JP2003080500A - Cantilever and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cantilever that can be produced by less number of processes, and a method for producing it, and also a method for producing a cantilever adaptable to a more three-dimensional shape. SOLUTION: In order to produce a fine cantilever, while condensing an excitation light and irradiating a photo-curing resin with the excitation light and photo polymerizing near the focal point, a condensing position is moved, whereby the cantilever and a supporting part thereof are integrally formed with the photo-curing resin. Further, a light axis of the excitation light is allowed to have the same direction as a lever face of the cantilever, so that a thin film-like lever can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cantilever with a probe used for atomic force microscopes, near-field optical microscopes, etc., and a minute cantilever for detecting minute mass changes.

[0002]

2. Description of the Related Art Conventionally, a cantilever with a probe and a minute cantilever for detecting a small mass used in an atomic force microscope, a near-field optical microscope, etc. are mainly manufactured by a semiconductor process using photolithography or the like, and silicon, It is made of a material such as silicon oxide or silicon nitride.

[0003]

In the method of manufacturing a cantilever by a semiconductor process utilizing photolithography as described above, there are many steps and the process requires a long time, and an etching step is required. There is a problem in that chemicals such as etching gas and etching gas are consumed. Further, since it is a so-called 2.5-dimensional processing method, the height of the probe is limited by the thickness of the substrate and the shape of the pattern.

In view of the above, it is an object of the present invention to provide a cantilever that can be manufactured in a small number of steps and a method of manufacturing the cantilever, and to provide a method of manufacturing a cantilever that can handle a more three-dimensional shape. .

[0005]

Therefore, in the present invention,
In order to make a fine cantilever, the excitation light is focused and irradiated on the photo-curable resin to perform photopolymerization in the vicinity of the focal point, and the focusing position is moved to integrate the cantilever and its supporting portion. It was decided to use a photo-curable resin. In the case of a cantilever with a probe used for an atomic force microscope, a near-field optical microscope, etc., the probe tip is integrally formed at a position near the cantilever and its supporting part and the end of the cantilever apart from the supporting part. It was to be. Furthermore, by making the optical axis of the excitation light the same direction as the lever surface of the cantilever, the lever can be formed in a thin film shape. On the other hand, as one method of forming the probe portion, by making the optical axis of the excitation light to be in the same direction as the surface of the film forming the probe, the probe portion becomes the apex of the thin film structure. The method of forming was devised. Another method of forming the probe portion is to irradiate the optical axis of the excitation light as a direction perpendicular to the lever surface of the cantilever and shift the focal point of the excitation light within the cantilever surface to propagate the cantilever. The light was caused to undergo photopolymerization on the surface opposite to the surface irradiated with the light to form a probe shape. Further, as one method of detecting displacement, a block or a cantilever having a resonance frequency higher than that of the cantilever is integrally formed as a counter electrode support body in parallel with the cantilever and with a slight gap therebetween, and the cantilever and the counter electrode are opposed to each other. Electrodes formed on the electrode support can detect electrostatic displacement of the cantilever.

Further, the tip of the opening mask needle held by the support arm integrally formed with the cantilever support is disposed close to the tip of the probe integrally formed with the cantilever, Then, by depositing a light-reflecting film on the surface on which the probe is formed, the reflecting film is not deposited on the tip of the probe because the tip of the opening mask needle is arranged close to the tip of the probe. By utilizing that
A probe having a minute optical aperture at the tip of the probe can be manufactured.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
A description will be given with reference to the drawings.

FIG. 1 schematically shows a cantilever according to the present invention and a method for producing the cantilever. In FIG. 1A, a container 101 filled with an uncured photocurable resin
In addition, by collecting and irradiating the excitation light 102,
It is schematically shown that the cantilever 104 and its supporting portion 105 are integrally formed of a photocurable resin by moving the light collecting position while performing photopolymerization at 03. Also in FIG. 1B, while the container 101 filled with the uncured photo-curable resin is condensed and irradiated with the excitation light 102, photopolymerization is performed in the vicinity of the focus 103,
It is shown that the cantilever 104 and its supporting portion 105 are integrally formed of the photocurable resin by moving the light collecting position, and further, the position near the end of the cantilever 104 apart from the supporting portion 105 is shown. The probe 106 is formed integrally with the. As described above, by forming the cantilever using the photocurable resin, it becomes possible to form the shape which was difficult in the conventional semiconductor process using photolithography or the like. Here, in particular, FIG.
In the case shown by, by setting the optical axis of the excitation light in the same direction as the lever surface of the cantilever, the resolution can be increased and a thinner lever can be formed as compared with the case where the optical axis is perpendicular to the lever surface. be able to. By making the cantilever thin, in the measurement of minute mass changes,
The detection sensitivity can be increased, and a weaker force can be detected by the atomic force microscope probe.

Next, FIG. 2 shows an example in which the probe portion is formed as an apex of a thin film structure by setting the optical axis of the excitation light in the same direction as the surface of the film forming the probe. It is shown. FIG. 2A is an example in which the surface of the cantilever 201 is positioned perpendicular to the optical axis of the excitation light, and the probe 202 is formed as a combination of thin film structures. The tip 203 is formed to have a minute apex. FIG. 2B shows the cantilever 20.
This is an example of the case where the surface No. 4 is oriented in the same direction with respect to the optical axis of the excitation light. The probe 205 is formed as a combination of thin film structures, and the tip 206 of the probe becomes a minute vertex. Is formed. As described above, the present invention has an advantage that the length of the probe can be arbitrarily set and that there is no restriction on the chip height which is a problem in etching a silicon wafer or depositing a thin film.

FIG. 3 is a diagram explaining the use of the probe of the present invention as an optical probe. As the photo-curable resin, urethane acrylate-based or epoxy-based photo-curable resin can be used. Since these materials have a certain light transmittance, the tip of the probe and the back of the probe are Light can be propagated to and from the cantilever surface located.
For example, as shown in FIG. 3A, the light 311 is introduced from the back surface of the probe, and the light 312 is emitted from the probe 312.
As in (b), the light 322 incident on the tip 321 of the probe and the light 323 propagating in the cantilever can be extracted from the back surface of the probe.

As the excitation light source of the present invention, a helium-cadmium laser, an argon laser or the like which can generate ultraviolet light having a wavelength of about 300 to 400 nm, or a titanium sapphire laser having a wavelength of 700 to 400 nm can be used.
A material capable of causing two-photon absorption at 800 nm can be used.

Further, FIG. 4 shows an example in which a lens shape 411 is formed on the lever surface on the back surface of the probe. As shown in FIG. 4A, when the parallel light 412 is introduced from the back surface of the probe, light can be condensed at the tip of the probe due to the lens shape, and the light 413 having a higher density is emitted from the probe. Can be emitted. As shown in FIG. 4B, when the light 422 incident on the tip 421 of the probe propagates the light 421 propagating in the cantilever from the back surface of the probe, the emitted light can be collimated by the lens shape. The detection efficiency can be improved.

FIG. 5 shows an example in which a light reflecting film for detecting displacement by light is formed when used as a probe for an atomic force microscope. FIG. 5A shows an example in which a metal thin film 511 such as aluminum or chromium is formed as a light reflecting film on the cantilever surface on the back side of the probe. The displacement detection light beam 512 is reflected by the metal thin film, and the displacement of the cantilever can be detected as an angle change of the reflected light beam. FIG. 5B shows an example in which a light reflecting film is formed on the surface of the cantilever on the side of the probe, and the light beam 522 for displacement detection passes through the inside of the cantilever.
Reflected by the metal thin film 521, in this case also, the displacement of the cantilever can be detected as an angle change of the reflected light beam.

FIG. 6 schematically shows a method of manufacturing a cantilever with a probe having an optical minute aperture. In FIG. 6A, the tip of the opening mask needle 613 is arranged close to the tip of the probe 612 integrally formed with the cantilever 611, and the cantilever support 615 is provided together with the support arm 614 thereof. It is formed integrally. As shown in FIG. 6B, when the light reflection film 626 is deposited on the probe side, the opening mask needle 61 is formed.
Since the tip of the probe 3 is arranged close to the tip of the probe 612, no reflective film is deposited on the probe tip. Next, as shown in FIG. 6C, the opening mask needle 613 and the support arm 614 are removed to complete the optical probe. Here, the support arm does not become a shadow on the cantilever surface when the light reflection film is deposited,
The structure must be thin and away from the cantilever surface. Here, a light beam 631 for displacement detection
Is reflected by the light reflection film 626 via the inside of the cantilever, and the displacement of the cantilever can be detected as an angle change of the light beam reflected by the cantilever.
Further, when the light 632 is introduced from the back surface of the probe, it can be made to function as a micro aperture type near-field optical microscope probe that takes out light from the micro aperture at the tip of the probe.

FIG. 7 schematically shows the structure of a cantilever when electrostatic displacement detection is performed. Figure 7
In (a), a block 712, which is parallel to the cantilever 711 and which is a counter electrode support, is formed integrally with the cantilever 711 with a slight gap. The electrode 713 on the cantilever 711 and the electrode 714 formed on the counter electrode support can electrostatically detect the displacement of the cantilever. In the example of FIG. 7A, a separation region 715 having a step is formed for insulation between electrodes. The counter electrode support may be a cantilever having a resonance frequency higher than that of the cantilever. In this case, as shown in FIG.
As shown in (b), a plurality of cantilevers 721 and a counter electrode support 722 may be paired to form a multi-cantilever array formed on a support 723.
By attaching a sensitive film to each of the multi-cantilever arrays, it is possible to construct a minute weight sensor selective for a plurality of chemical substances. FIG. 8 is a diagram showing an example of a method of forming a probe different from the above. In FIG. 8, by irradiating the optical axis of the excitation light 811 from a direction perpendicular to the lever surface of the cantilever 812 and shifting the focal point 813 of the excitation light within the cantilever surface, the light 814 propagating through the cantilever changes the light. On the surface opposite to the irradiated surface, photopolymerization occurs, and the probe shape 8
15 is formed.

FIG. 9 shows an example of a shear force type cantilever for a probe microscope. In FIG. 9, a probe 91 whose axial tip is directed to the tip of the cantilever 912 formed on the support portion 911 in the lever axis direction.
3 is formed. By applying vibration to the lever in the vertical direction, it can be used as a shear force type probe due to the elastic property of the cantilever. Also in this example, as described above, light can be propagated in the cantilever and used as an optical probe.

[0017]

As described above, according to the present invention, it is possible to reduce the number of steps without being restricted by the complexity of steps and the height of the probe, which are problems in the manufacturing method of the cantilever by the semiconductor process using photolithography. It has become possible to provide a cantilever that can be manufactured and a method for manufacturing the cantilever, and it has become possible to manufacture a cantilever that can handle a more three-dimensional shape.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a cantilever of the present invention and a method for producing the cantilever.

FIG. 2 is a diagram schematically showing a configuration of a probe portion of a cantilever of the invention.

FIG. 3 is an illustration of an example of using the probe of the present invention as an optical probe.

FIG. 4 is a schematic view of a cantilever in which a lens shape is formed on the lever surface on the back surface of the probe of the present invention.

FIG. 5 is a schematic diagram of a cantilever formed with a light reflecting film of the present invention.

FIG. 6 is a schematic view showing a method for manufacturing a cantilever with a probe having an optical microscopic aperture according to the present invention.

FIG. 7 is a schematic diagram of a cantilever for detecting electrostatic displacement according to the present invention.

FIG. 8 is a diagram showing an example of a method for forming a probe according to the present invention.

FIG. 9 is a schematic view of a shear force type cantilever for a probe microscope of the present invention.

[Explanation of symbols]

101 container 102 Excitation light 103 near focus 104 cantilever 105 Support 106 probe 201 cantilever 202 probe 203 Tip of probe 204 cantilever 205 probe 206 Tip of the probe 311 Introduction light 313 Synchrotron radiation 321 probe tip 322 incident light 411 lens shape 412 parallel light 413 Synchrotron radiation 421 probe tip 511 metal thin film 512 light beam 521 metal thin film 522 light beam 611 cantilever 612 probe 613 Needle for opening mask 614 Support arm 615 cantilever support 626 Light reflection film 631 light beam 632 Introduction light 711 cantilever 712 Counter electrode support 713 electrode 714 electrode 715 Separation area 721 cantilever 722 Counter electrode support 811 Excitation light 812 cantilever 813 Focus of excitation light 814 propagated light 815 probe shape 911 support 912 cantilever 913 probe

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 13/16 G01N 13/16 C G12B 21/06 G12B 1/00 601C 21/08 601D F term (reference) 2F063 AA02 BA30 BB05 DA01 DC08 HA04 KA01 KA03 4F213 AA44 AH05 WA25 WL03 WL43 WL53

Claims (17)

[Claims] 1. A fine cantilever is formed by moving excitation light while condensing excitation light onto a photo-curing resin to cause photopolymerization in the vicinity of a focal point to move the light collection position, and the cantilever and its supporting portion. A cantilever characterized by being integrally formed. 2. The cantilever according to claim 1, wherein a probe tip is integrally formed at a position near the end of the cantilever and a supporting portion thereof, and a position apart from the supporting portion. 3. The cantilever according to claim 1, wherein the cantilever is formed into a thin film by making the optical axis of the excitation light the same direction as the lever surface of the cantilever. 4. The probe portion is formed as an apex of a thin film structure by setting the optical axis of the excitation light to be in the same direction as the surface of the film forming the probe. The cantilever according to claim 1. 5. The light-curable resin is a light-transmissive material and is capable of propagating light between the tip of the probe and the cantilever surface located on the back surface of the probe. The cantilever according to item 2. 6. The cantilever according to claim 5, wherein a lens shape is formed on the tip of the probe and the back surface of the probe. 7. The cantilever according to claim 1, wherein at least one surface of the cantilever is coated with a light reflecting film. 8. The cantilever according to claim 2, wherein one surface of the cantilever on the probe side is coated with a light reflecting film. 9. The cantilever according to claim 2, wherein a light-reflecting film is coated on one surface of the cantilever on the probe side except the tip of the probe. 10. A block or a cantilever having a resonance frequency higher than that of the cantilever is integrally formed as a counter electrode support body in parallel with the cantilever and with a slight gap therebetween. The electrostatic displacement of the cantilever can be detected by an electrode formed on the substrate.
The described cantilever. 11. By irradiating the optical axis of the excitation light from a direction perpendicular to the lever surface of the cantilever and shifting the focus of the excitation light within the cantilever surface,
3. The cantilever according to claim 2, wherein the cantilever has a probe formed by causing photopolymerization on the surface opposite to the surface irradiated with the excitation light, the excitation light propagating through the cantilever. 12. A method of manufacturing a fine cantilever, wherein a photocurable resin is condensed and irradiated with excitation light to cause photopolymerization in the vicinity of a focal point, and the condensing position is moved to thereby move the cantilever. A method of manufacturing a cantilever, which comprises integrally forming a supporting portion and a supporting portion thereof with a photocurable resin. 13. The probe tip is integrally formed at a position near the end of the cantilever and the supporting portion thereof and the end of the cantilever separated from the supporting portion.
A method for producing the described cantilever. 14. The method of manufacturing a cantilever according to claim 12, wherein the lever is formed in a thin film shape by setting the optical axis of the excitation light in the same direction as the lever surface of the cantilever. 15. The probe part is formed as an apex of a thin film structure by setting the optical axis of the excitation light in the same direction as the lever surface of the probe of the cantilever. How to make a cantilever. 16. By irradiating the optical axis of the excitation light from a direction perpendicular to the lever surface of the cantilever and shifting the focus of the excitation light within the cantilever surface,
14. The method for producing a cantilever according to claim 13, wherein light propagating through the cantilever causes photopolymerization on the surface opposite to the surface irradiated with the light to form a probe shape. 17. A distal end of an opening mask needle held by a support arm integrally formed with a cantilever support is disposed in close proximity to the distal end of a probe integrally formed with the cantilever. Then, by depositing a light-reflecting film on the surface on which the probe is formed, the reflecting film is not deposited on the tip of the probe because the tip of the opening mask needle is arranged close to the tip of the probe. 14. The method for producing a cantilever according to claim 13, wherein a probe having a minute optical aperture at the tip of the probe is produced by utilizing this fact.