JP3517818B2 - Near field microscope - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a near-field microscope, and more particularly to a near-field microscope that is versatile and that can obtain observation results with high resolution.

[0002]

2. Description of the Related Art Optical microscopes using light are widely used for not only unevenness information of an object to be observed (sample) but also polarization or wavelength dependence observation, which is not useful for grasping characteristics of the object to be observed. Needless to say. In an ordinary light microscope, the spatial resolution is limited by the diffraction limit of light. It is well known that the resolution of an optical microscope is generally given by (wavelength of light) / (numerical aperture of lens), and its value is on the order of wavelength. That is, there is a theoretical limit to the resolution in the observation of polarization / wavelength dependence by an ordinary optical microscope.

A near-field microscope is known as a means for overcoming this limitation. Generally, scattered light is generated from the observed object irradiated with light, and this scattered light is composed of two components, a component propagating to infinity and a non-propagating component localized near the observed object. The non-propagating component is rapidly attenuated as it moves away from the object to be observed, and exists only at a distance about the size of the fine structure of the object to be observed. Of the structural spatial frequency of the observed object, the propagation component transmits only a component having a size as large as the wavelength of light.

Since an ordinary optical microscope has a photodetector arranged at a distance from an object to be observed and detects only a propagating component of scattered light, in principle, only a spatial resolution of about the wavelength can be realized. On the other hand, the near-field microscope brings the observed object close to the photodetector, and detects the non-propagating component existing only in the vicinity of the observed object.

This non-propagating component contains a spatial frequency component equal to or less than the wavelength of the structure of the object to be observed. A near-field microscope can realize a spatial resolution of a wavelength or less by detecting a non-propagating component in scattered light from an observed object.

In an actual near-field microscope, a probe is brought close to an object to be observed, non-propagating light from the object to be observed is scattered, and scattered light from the tip of the probe is detected by a photodetector.
Since the resolution is about the size of the probe tip, it is necessary to reduce the size of the probe tip in order to improve the resolution. Currently, a probe having an effective size diameter on the order of 10 nm is used.

However, in the near field microscope,
When the effective size of the probe tip is reduced, the intensity of the scattered light due to it is drastically reduced. Further, the illumination light that illuminates the observed object illuminates the observed object in a range sufficiently larger than the size of the probe tip. Therefore, the intensity of the background light becomes larger than the intensity of the scattered light from the tip of the probe, and it is necessary to reduce the background light intensity in order to obtain a near field image with a good SN ratio.

In the near-field microscope, as a conventional method for reducing the intensity of the background light, an evanescent light illuminating method or a method using a fine aperture type probe is known.

The evanescent light illumination method is a method of generating evanescent light that is localized only in the vicinity of the wavelength of the object to be observed. Convert and detect. Since the evanescent light from the other part of the observed object does not reach the photodetector, the background light can be reduced.

Further, in the method using the micro-aperture type probe, a probe coated with an object that absorbs the irradiation light is used while leaving the micro-aperture at the tip. Since the light from the observed object reaches the photodetector only through the minute opening at the tip, the background light can be reduced.

FIG. 5 is a schematic view showing a schematic structure of a near-field microscope adopting a conventional evanescent light illumination method.

In the figure, 1 is a light source, 2 is a prism,
3 is an observed object, 4 is evanescent light, 5 is a photodetector, 9 is a scanning mechanism, 91 is a probe, and 92 is a probe 9.
1, a probe 501, an optical system 501 such as a condenser lens,
02 is a preamplifier.

As shown in the figure, the light source 1 and the prism 2 are arranged so that the irradiation light 7 from the light source 1 is totally reflected on the upper surface of the prism 2. Here, the central wavelength of the light source 1 is λ. In the case of such an arrangement relationship, as shown schematically in the same figure, the exudation of light of a wavelength (λ) called evanescent light 4 occurs on the upper surface of the prism 2. The evanescent light 4 is modulated by the observed object 3.

The modulated evanescent light 4 is scattered by the probe 92 provided on the probe 91, and the scattered light is condensed by the optical system 501 such as a scattered light condensing lens.
It is converted into an electric signal (photocurrent) by the photodetector 5 and amplified by the preamplifier 502. Further, by scanning the probe 92 provided on the probe 91 with the scanning mechanism 9 in the plane of the observed object 3, a two-dimensional light distribution image can be obtained.

The tip of the probe 92 is sharpened so as to have a wavelength (λ) or less, and the evanescent light 4 is emitted from the tip.
Are scattered. The spatial resolution is about the diameter of the curvature of the tip of the probe 92. Further, the evanescent light 4 is localized in the vicinity of the object 3 to be observed, and is abruptly attenuated as it moves away from the object 3 to be observed, and does not reach the photodetector 5, so that the background light can be reduced. it can.

Regarding this evanescent light illumination method,
It is described in the following document (a).

(A) Appl.Phys.Lett, (1993), vol.62 (5),
p461 FIG. 6 is a schematic diagram showing a schematic configuration of a near-field microscope adopting a conventional microaperture probe.

In the figure, 1 is a light source, 3 is an object to be observed, 5 is a photodetector, 9 is a scanning mechanism, 20 is a sample stage, and 63.
Is a minute aperture, 612 is an optical fiber (probe) with a sharpened tip, and 622 is a metal layer. Here, the metal layer 62
No. 2 is coated so that a minute opening 63 having a diameter of (λ) or less is formed at the tip of the optical fiber 612.

Of the irradiation light 7 from the light source 1 that has passed through the object 3 to be observed, the irradiation light 32 immediately below the optical fiber passes through the minute aperture 63, reaches the photodetector 5, and is converted into an electric signal. It A two-dimensional image of the observed object 3 can be obtained by two-dimensionally scanning the optical fiber 612 in the plane of the observed object 3 by the scanning mechanism 9.

In this case, of the irradiation light 7 transmitted through the object 3 to be observed, the background light 31 which is the irradiation light other than the irradiation light directly below the optical fiber is reflected and absorbed by the metal layer 622, and is reflected by the photodetector 5. Does not reach. As a result, the background light can be reduced, and the resolution is almost equal to the diameter of the minute aperture 63, so that the resolution that breaks the diffraction limit is possible.

The method using this microaperture probe is described in the following document (b).

(B) Science, (1992), vol.257, p189

[0023]

However, the conventional proximity microscopes shown in FIGS. 5 and 6 have the following problems.

In the evanescent light irradiation method shown in FIG. 5, when the area of the part where the evanescent light 4 is generated is large, the scattered light generated by the unevenness of the observed object 3 or minute dust or the like becomes the background light. That is, in order to remove the background light, an optical system for limiting (squeezing) the size of the totally reflected portion of the irradiation light 7 from the light source 1 is required, and the optical system is complicated and has many restrictions. There was a problem.

Further, in the method using the evanescent light 4, the irradiation light does not reach the observed object 3 having a height equal to or more than the length of the seeping out of the evanescent light 4.
Objects with large irregularities or objects with large thickness 3
However, the object 3 to be observed is difficult to apply only to a thin film or a transparent plate-like object.

In order to eliminate such limitation of the object 3 to be observed, the illumination light 7 is applied to the object 3 to be observed by the probe 91.
It is necessary to use reflection type illumination that irradiates from the same side. However, the reflection type illumination cannot illuminate the observed object 3 with the evanescent light 4. That is, the evanescent light irradiation method shown in FIG. 5 has a problem that there is a limit to the observed object 3 that can be observed.

In the method using the micro-aperture type probe shown in FIG. 6, it is necessary to form the micro-aperture 63 on the order of 10 nm at the tip of the sharpened optical fiber (probe) 612. The conventional method of making microscopic apertures has poor mass productivity,
In addition, the optical fiber 612 is easily broken during observation and is not suitable for industrialization.

Although aluminum is used as the metal layer 622 shown in FIG. 6, the absorption coefficient of aluminum for visible light is about 15 nm, and the thickness of the metal layer 622 needs to be about several tens of nm. Therefore, the tip diameter of the optical fiber 612 is about 50 nm or more. That is, the tip diameter of the optical fiber 612 is larger than the opening diameter of the minute opening 63.

Generally, in the near-field microscope, in order to obtain high-resolution optical information from the object 3 to be observed, which has irregularities, it is necessary to control the gap between the object 3 to be observed and the tip of the probe (91, 612). Is. In this case, in the method using the micro-aperture probe shown in FIG. 6, the spatial resolution in the object 3 to be observed in the gap control is the metal layer (aluminum film).
Since the optical spatial resolution is about the tip diameter of the optical fiber 612 including 622 and the aperture diameter of the minute aperture 63,
The spatial resolution of the gap control is lower than the optical spatial resolution,
The optical spatial resolution could be limited to the spatial resolution of the gap control.

Further, in the method using the micro-aperture probe shown in FIG. 6, as a method for performing the reflection type illumination in order to eliminate the limitation of the object 3 to be observed, as shown in FIG. The light 701 is irradiated through the optical fiber 612 from the minute opening 63 onto the observed object 3. Then, there is a method of detecting the light 702 (signal light that is reflected by the object 3 to be observed and includes optical information of the object 3 to be observed) that has entered the minute aperture 63 and passed through the optical fiber 612. Since the signal light passes through twice, there is a possibility that a sufficient amount of light cannot be obtained because the signal light becomes very small.

As another method for performing the reflection type illumination in order to eliminate the limitation of the object to be observed 3, as shown in FIG. 8, an optical system 501 such as a condenser lens and a photodetector 5 are used. The illumination light 7 from the light source 1 is placed outside the optical fiber 612.
01 is irradiated through the optical fiber 612 from the minute opening 63 to the object 3 to be observed. Then, the 703 light reflected from the observed object 3 is condensed by the optical system 501 such as a condensing lens and then converted into an electric signal by the photodetector 5, so that the light 703 reflected from the observed object 3 is converted. There is a method of detecting the light without passing through the optical fiber 612, but the light that can be condensed outside the optical fiber 612 passes through the minute opening 63 near the surface of the observed object 3 by the thickness of the metal layer 622 of several tens nm. It is only the light 703 that has passed out of the optical fiber 612.

Moreover, since the gap between the portion of the metal layer 622 and the surface of the object 3 to be observed is equal to or less than the wavelength of the illumination light 701 from the light source 1, interference may occur due to multiple reflection of light in the gap. However, outside the thickness of the metal layer 622, there is a possibility that a sufficient amount of light for converting into an electric signal by the photodetector 5 cannot be obtained. Further, there is a problem that the solid angle of light converted into an electric signal by the photodetector 5 is also limited.

The optical path opposite to this is taken and the optical fiber 6
The method of collecting light from the outside of 12 to the observed object 3 in the vicinity of the minute aperture and detecting the light reflected by the observed object 3 and incident on the minute aperture 63 via the optical fiber 612 is the same as in the above case. Similarly, it goes without saying that a sufficient amount of light may not be obtained. That is, the micro-aperture probe shown in FIG. 6 has a problem in that reflection-type illumination is difficult and the observed object 3 that can be observed is limited.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a simple point light source at the probe tip in a near-field microscope. It is an object of the present invention to provide a technique capable of reducing background light with an optical system.

Another object of the present invention is to provide a point light source at the probe tip in a near field microscope,
An object of the present invention is to provide a technique suitable for industrialization, which enables reflective illumination and has no limitation on the observed object.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0037]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

Light irradiating means for irradiating the object to be observed with the input light having the central wavelength λ, and transmitting the input light having the central wavelength λ
A probe made of a material to be provided, which is provided in a portion closest to the observed object of the probe, outputs light having a shorter wavelength than the wavelength of the input light from the light irradiation means , and
Point light source that irradiates the object to be observed with the light of the short wavelength
The infrared-visible conversion phosphor and the short wavelength light are
Light detecting means for detecting the light modulated by the near field of the observation object, a proximity field microscopy to have a scanning means for changing the relative positional relationship between the probe, the light irradiation
The means for projecting the projection on the surface of the observed object
The input light is radiated from a region spatially identical to the probe, and the distance between the object to be observed and the probe is λ or less.

That is, in the present invention, the light wavelength conversion means is added to the tip of the probe, and the illumination light has, for example, a central wavelength λ.
The infrared ray having the center wavelength λ is converted into visible light by the light wavelength conversion means, and only the converted visible light is detected by the light detection means.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In all the drawings for explaining the embodiments, parts having the same functions are designated by the same reference numerals, and the repeated description thereof will be omitted.

[First Embodiment] FIG. 1 is a schematic diagram showing a schematic configuration of a near-field microscope which is an embodiment of the present invention.

The purpose of this embodiment is to reduce background light and to observe a more general object to be observed.
In, the case of using a cantilever beam-shaped probe will be described.

In FIG. 1, 3 is an object to be observed, 9 is a scanning mechanism, 11 is an infrared light source, 20 is a sample stage, 51 is a photodetector, 81 is a laser light source, 82 is a laser spot position detector, and 91 is A cantilevered probe, 92 is a probe provided at the tip of the cantilevered probe 91, 100 is an infrared-visible conversion phosphor, 501 is an optical system such as a condenser lens, 502
Is a preamplifier and 503 is a wavelength filter. The infrared light source 11 irradiates the observed object 3 with infrared light having a wavelength of 1.5 μm, for example. A sharpened probe 92 is provided at the tip of the cantilever probe 91.

The laser light source 81 and the laser spot position detector 82 are for controlling the gap between the cantilever probe 91 and the object 3 to be observed. When the atomic force acting between the tip of the probe 92 provided at the tip of the cantilever-shaped probe 91 and the observed object 3 changes, the reflected light of the laser light source 81 reflected by the cantilever-shaped probe 91 changes. The spot position changes. This change is detected by the laser spot position detector 82, and the distance between the tip of the probe 92 and the observed object 3 is controlled by the scanning mechanism 9 based on the signal from the laser spot position detector 82.

A method of controlling the gap between the probe 92 and the observed object 3 from the atomic force acting between the tip of the probe 92 and the observed object 3 is described in the following document (C). This method is called an optical lever method, and can be controlled with a resolution of 1 angstrom or less.

(C) Applyed Physics Letters (1988) vo
l.53, p1045 Infrared-visible conversion phosphor 100 is 10n at the tip of the probe 92.
The size is added in the order of m. The infrared-visible conversion phosphor absorbs infrared light (wavelength 0.8 to 1.6 μm) and emits visible light (generally wavelength 0.3 to, as described in the following document (d)). It is a fluorescent substance that emits 0.8 μm).

(D) Appl. Phys. Lett. 39 (8), 1981, pp587,
Appl.Phys.Lett.65 (2), 1994, p129 As a material of the infrared-visible conversion phosphor 100, Er ³⁺
Among those containing ions, chlorides, oxides, sulfides, fluorides, oxyhalides and the like are known. In the present embodiment, the infrared-visible conversion phosphor 100 is Er ^3+.
YCl ₃ , PbCl ₂ , KCl, ErCl ₃ containing ions
The case of using a sintered body of a chloride mixture such as These materials absorb light having a wavelength of 1.5 μm and emit light having a wavelength of 0.55 μm.

The infrared-visible conversion phosphor 100 is an infrared light source 1
The irradiation light 71 from 1 is converted into visible light 72. As a result, the infrared-visible conversion phosphor 100 becomes a point light source that irradiates the observed object 3 with the visible light 72.

The visible light 72 is modulated by the near field with the object 3 to be observed (illustrated schematically by 41 in the figure), and the modulated light 73 is collected by the optical system 501 such as a condenser lens. After the light is emitted, it is converted into an electric signal (photocurrent) by the photodetector 51, amplified by the preamplifier 502, and measured as signal light. As a result, a two-dimensional light distribution image of the observed object 3 can be finally obtained.

The wavelength filter 503 attenuates the intensity of infrared light. Therefore, the photodetector 51 is made more sensitive to the visible light (72, 73) than the irradiation light 71 from the infrared light source 11. Alternatively, when a single crystal Si photodiode is used as the photodetector 51, the photoelectric conversion efficiency for infrared rays having a wavelength of 1.2 μm or more is generally 1 / 100,000, which is a wavelength of 0.8 μm or less. Almost no detection of infrared rays 71 of 5 μm,
Only the visible light 72 can be detected.

Therefore, even if the irradiation area of the infrared ray 71 is large, it does not become background light, and only the visible light (72, 73) from the phosphor 100, which can be regarded as a point light source with a diameter of the order of 10 nm, is detected. Be subject to.

When the cantilever beam-shaped probe 91 is made of Si, the cantilever beam-shaped probe 9 emits infrared light having a wavelength of 1.5 μm.
The infrared light 71 can be emitted from the side of the cantilevered probe 91 because it is not absorbed by 1.

As described above, in the present embodiment, it is possible to perform the reflection type illumination without using the evanescent light, and the observable object 3 to be observed has its shape, thickness,
It is no longer limited by transparency. As a result, in the present embodiment, it is possible to reduce the background light and remove the limitation on the observed object.

[Embodiment 2] FIG. 2 is a schematic diagram showing a schematic configuration of a near-field microscope which is another embodiment of the present invention.

This embodiment is intended to further reduce the background light as compared with the above-mentioned embodiments, and in FIG. 2, a case where a cantilever-shaped probe is used will be described.

In FIG. 2, 2 is a prism, 3 is an object to be observed, 4 is evanescent light schematically shown, 9 is a scanning mechanism, 11 is an infrared light source, 51 is a photodetector, 81 is a laser light source, and 82 is a light source. A laser spot position detector, 91 is a cantilevered probe, 92 is a probe at the tip of the cantilevered probe 91, 100 is an infrared-visible conversion phosphor, 501 is an optical system such as a condenser lens, 502 Is a preamplifier and 503 is a wavelength filter.

Also in this embodiment, the cantilever beam-shaped probe 9 is used.
The infrared-visible conversion phosphor 100 is attached to the tip of the first probe 92.
It is added with a size of 0 nm order. Irradiation light 71 from the infrared light source 11 is totally reflected on the upper surface of the prism 2,
The evanescent light 4 exudes on the opposite side. Since the observed object 3 is on that surface, the evanescent light 4 is modulated. The evanescent light 4 is localized in the vicinity of the object 3 to be observed, abruptly attenuates as it moves away from the object 3 to be observed, and does not reach the photodetector 51.

The scanning mechanism 9 scans the object 3 to be observed with the probe 92, so that the evanescent light 4 exuding several tens of nm is converted by the infrared-visible conversion phosphor 100 added to the tip of the probe 92. It is converted into visible light 72 and scattered. The scattered light 73 is generated by the optical system 5 such as a condenser lens.
After being condensed by 01, it is converted into an electric signal (photocurrent) by the photodetector 51, amplified by the preamplifier 502, and measured as signal light. As a result, a two-dimensional light distribution image of the observed object 3 can be finally obtained.

In the case of the present embodiment, even when the size of the infrared-visible conversion phosphor 100 added to the tip of the probe 92 is larger than the diameter of the order of 10 nm, only the portion irradiated with the evanescent light 4 serves as a scatterer. Since it works, the effective size of the infrared-visible conversion phosphor 100 is approximately the length of the evanescent light 4 oozing out, and high resolution can be obtained.

As a result, in the present embodiment, even if the size of the infrared-visible conversion phosphor 100 is large, high resolution can be obtained, so that the cantilever-shaped probe 91 can be easily manufactured.

[Third Embodiment] FIG. 3 is a schematic diagram showing a schematic configuration of a near-field microscope which is another embodiment of the present invention.

In the present embodiment, a photodetector (photodiode) is incorporated in a cantilever beam probe, and an external photodetector is unnecessary.

In FIG. 3, 3 is an object to be observed, 9 is a scanning mechanism, 11 is an infrared light source, 20 is a sample stage, 81 is a laser light source, 82 is a laser spot position detector, 911 is a cantilever probe, Reference numeral 92 is a probe at the tip of the cantilever probe 911, 100 is an infrared-visible conversion phosphor, 2001 is a photodiode, 502 is a preamplifier, and 921 is a signal line. The cantilevered probe 911 is a cantilevered probe having a photodiode formed at its tip, and the infrared-visible conversion phosphor 100 having a size of the order of 10 nm is added to this tip.

Also in this embodiment, the irradiation light 71 from the infrared light source 11 irradiates the infrared-visible conversion phosphor 100.
The infrared-visible conversion phosphor 100 converts the irradiation light 71 from the infrared light source 11 into visible light 72. As a result, the infrared-visible conversion phosphor 100 becomes a point light source that irradiates the observed object 3 with the visible light 72.

The visible light 72 is modulated in the near field with the object 3 to be observed, and the modulated light 73 is, as shown in FIG. 3B, the photodiode 2 of the cantilever beam probe 911.
In 001, it is converted into an electric signal (photocurrent), and the preamplifier 5
At 02, current-voltage conversion and amplification are performed, and the signal light is measured. As a result, finally 2 of the observed object 3
It is possible to obtain a three-dimensional light distribution image.

In this embodiment, unlike the second embodiment, the light 73 modulated by the near field with the observed object 3 is used.
Is the photodiode 20 of the cantilevered probe 911.
At 01, it is converted into an optical signal.

At this time, since the photodiode 2001 is a single crystal Si photodiode, a wavelength of 1.2 is generally used.
The photoelectric conversion efficiency for infrared rays of μm or more has a wavelength of 0.8.
Since it is 1 / 100,000 or less of μm, infrared rays 71 having a wavelength of 1.5 μm are hardly detected, and only visible light 73 can be detected. Therefore, the infrared light 71 that is the background light can be filtered and removed. Accordingly, in the present embodiment, the optical system 501 such as the condenser lens is used.
Therefore, the photodetector 51 becomes unnecessary, and the device configuration can be downsized and simplified.

FIG. 4 shows a cantilever beam-shaped probe 9 shown in FIG.
It is a figure which shows schematic structure of an example of 11.

In FIG. 4, reference numerals 21 and 22 are electrodes, 23 is a p region, 24 is an n region, 231 is a high-concentration p region, and 24.
1 is a high-concentration n region, 30 is an antireflection film, 50 is a protrusion,
502 is a preamplifier and 921 is a signal line.

The electrodes 21 and 22 are made of aluminum,
Under the electrodes 21 and 22, in order to make ohmic contact with the electrodes 21 and 22, a high concentration region 23 of p and n is formed.
1,241 are provided. When light is incident on the pn junction to which a constant voltage is applied, a photocurrent according to the intensity of the incident light flows through the pn junction. Therefore, the scattered light scattered by the observed object 3 is reflected by the pn junction. The light intensity of scattered light can be measured by converting the current into a current and measuring the photocurrent.

Further, a silicon oxide film having a thickness of about 100 nm is provided as the antireflection film 30, and the reflectance thereof is reduced to about several%. As a material of the antireflection film 30, a material having a refractive index of about 2 is suitable for silicon, and it goes without saying that silicon nitride, for example, is effective in addition to silicon oxide.

The cantilever beam probe 911 shown in FIG.
Since the needle-like protrusion 50 is provided at the tip of the needle-shaped protrusion 50, the object 3 to be observed can be observed even when the object 3 to be observed has large irregularities such as grooves, which is advantageous in terms of versatility.

The cantilever beam probe 91 shown in FIG.
1 includes Japanese Patent Application No. 6-222, which has already been filed by the same applicant, in addition to the cantilever beam probe 911 shown in FIG.
Those described in No. 060 can be used.

Further, in the present embodiment, the case of the pn junction has been described, but instead of the pn junction, a pin junction in which an insulating layer is sandwiched between PN junctions or a Schottky junction (metal-semiconductor junction) is used. Is also possible.

As described above, the invention made by the present inventor is
Although the specific description has been given based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and needless to say, various modifications can be made without departing from the scope of the invention.

[0077]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) According to the present invention, in the near-field microscope, when the surface of the object to be observed is scanned by the probe and the intensity distribution of light near the surface is detected, an optically complicated system is not used, It is possible to perform measurement with less background light than signal light.

(2) According to the present invention, in the near-field microscope, not only transmissive evanescent light illumination but also reflective illumination is possible.

(3) According to the present invention, it is possible to provide a near-field microscope which is versatile and suitable for industrialization without being limited by the object to be observed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a near-field microscope which is an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of a near-field microscope which is another embodiment of the present invention.

FIG. 3 is a schematic diagram showing a schematic configuration of a near-field microscope that is another embodiment of the present invention.

FIG. 4 is a diagram showing a schematic configuration of an example of the cantilever beam probe shown in FIG.

FIG. 5 is a schematic diagram showing a schematic configuration of a near-field microscope adopting a conventional evanescent light illumination method.

FIG. 6 is a schematic diagram showing a schematic configuration of a near-field microscope that employs a conventional micro aperture probe.

FIG. 7 is a diagram for explaining a problem in the case of performing reflection-type illumination in order to eliminate restrictions on an object to be observed in a near-field microscope that employs a conventional small aperture probe.

FIG. 8 is a diagram for explaining a problem in the case of performing reflection-type illumination in order to eliminate restrictions on an object to be observed in a near-field microscope adopting a conventional micro aperture probe.

[Explanation of symbols]

1 ... Light source, 2 ... Prism, 3 ... Observed object, 4 ... Evanescent light, 5, 51 ... Photodetector, 9 ... Scanning mechanism, 11
... infrared light source, 20 ... sample stand, 21, 22 ... electrode, 23
... p region, 24 ... n region, 231 ... high-concentration p region, 2
41 ... High-concentration n region, 30 ... Antireflection film, 50 ... Protrusion, 63 ... Minute aperture, 81 ... Laser light source, 82 ... Laser spot position detector, 91, 911 ... Probe, 92
... Probe, 100 ... Infrared-visible conversion phosphor, 502 ... Preamplifier, 503 ... Wavelength filter, 612 ... Optical fiber, 6
22 ... Metal layer, 921 ... Signal line, 2001 ... Photodiode.

Continuation of front page (56) Reference JP-A-5-173076 (JP, A) JP-A-8-86793 (JP, A) JP-A-5-134189 (JP, A) JP-A-9-257812 (JP , A) JP 8-88252 (JP, A) JP 8-82633 (JP, A) JP 8-21843 (JP, A) JP 8-62228 (JP, A) JP 8-334521 (JP, A) JP-A-7-174770 (JP, A) JP-A-8-210829 (JP, A) JP-A-7-13082 (JP, A) JP-B 7-27118 (JP, A) B2) International Publication 95/33207 (WO, A1) U.S. Pat. , USA, American Institute of Physics, October 15, 1981, Vol. 39, No. 8, p. 587-589 Junichi Ohwaki, Yuhu Wang, "1.3 [mu] m to visible upconversion ion Dy3 + -and Er3 + -codoped Basicth 11th, 1994, Phys. Volume 65, Issue 2, p. 129-131 N.I. F. van Hulst, M .; H. P. Moers, OF J. Noordman, R .; G. Tack, F.M. B. Segerink, and B.C. Boelger, "Near-field optical microscopic using a silicon-nitride probe", Applied Physics Letters, No. 62, May 1993, May 1993, October of 1993. 461-463 (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 13/10-13/24 G12B 21/00-21/24 JISST file (JOIS)

Claims (4)

(57) [Claims] 1. A light irradiating means for irradiating an object to be observed with an input light having a central wavelength λ , a probe made of a material which transmits the input light having the central wavelength λ, and the probe. The output of light having a shorter wavelength than the wavelength of the input light from the light irradiating means provided in the portion closest to the observed object, for the observed object, of the short wavelength
An infrared-visible conversion phosphor that serves as a point light source that irradiates light, and the short-wavelength light is modulated in the near field of the observed object.
Light detecting means for detecting the light was directed to a proximity field microscopy to have a scanning means for changing the relative positional relationship between the probe, the light irradiation means, to the surface of the object to be observed object ,Previous
A near-field microscope characterized in that input light is emitted from the same spatial area as the probe, and the distance between the object to be observed and the probe is λ or less. 2. The output wavelength of light from the infrared-visible conversion phosphor is 1.1 μm or less, and the photodetection means includes a photodetector sensitive to light having a wavelength of 1.1 μm or less. The near-field microscope according to claim 1. 3. The output wavelength of the light from the infrared-visible conversion phosphor is 1.1 μm or less, and the light detecting means has a light wavelength discriminating means for discriminating light having a wavelength of 1.1 μm or less. The near-field microscope according to claim 1. 4. The photodetector of the photodetection means is the professional photodetector.
The photodetector of the photodetection means is a pn junction or a pin junction.
Or a semiconductor device including a Schottky junction, and the pn
Light generated in junction, pin junction or Schottky junction
Proximity field microscope according to 請 Motomeko 2 <br/>; and a electrode and a wiring for measuring the current.