JP2002340771A - Scanning proximity field optical microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an easy-to-set high S/N scanning proximity field optical microscope in which the incident system and the optical microscope section are integrated while reducing the cost and the size. SOLUTION: The scanning proximity field optical microscope comprises a probe 2, a probe holding member 3, means for bringing the forward end of the probe 2 close to a sample 1, means 7 for irradiating the vicinity of the forward end of the probe 2 with light from a light source 16, means for detecting light from the vicinity of the forward end of the probe 2 through a detector 15, and an optical microscopic means for observing the sample 1 substantially perpendicularly from above. The observing means comprises an objective lens 7 disposed substantially perpendicularly to the sample 1 wherein at least one line starting from the forward end part of the probe 2 is disposed to traverse at least a part of the effective diameter of the objective lens 7 without being blocked by the probe 2 and the probe holding member 3 and the objective lens 7 also serves a part of means for irradiating the tip of the probe 2 with light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning near-field optical microscope, and more particularly, to a scanning near-field optical microscope having a low cost, a small size, easy setting, and a high S / N ratio.

[0002]

2. Description of the Related Art A scanning near-field optical microscope (hereinafter referred to as SNO)
M: Scanning Near-Field Opt
ical Microscope) is a probe having an opening with a diameter smaller than the wavelength of light at the tip or a probe with a sharpened non-opening tip with a curvature smaller than the wavelength of light near the sample. This is an apparatus for measuring optical information of a minute region of a sample by scanning relatively with the sample.

The scanning near-field optical microscope can obtain a resolution up to the above-mentioned aperture diameter or a radius of curvature of a tip portion (up to several tens of nm) as compared with an optical microscope whose resolution is limited by a diffraction limit. That is what is expected.

[0004] SNOMs can be classified according to the type of probe, but can be broadly classified into an aperture type having an aperture and a non-aperture scattering type as described above. The differences are as follows. First, the aperture type irradiates a sample with light through the opening or detects light from the sample through the opening to obtain optical information of the sample. On the other hand, in the scattering type, a local electric field generated on the surface of a sample due to incident light from the outside is scattered by a sharpened probe tip, and optical information of the sample is obtained by detecting the scattered light.

[0005] Among these, the scattering type SNOM can be smaller in diameter than the opening type of the opening type, and is expected to be a higher resolution type SNOM. The operation is shown in FIG.
This will be described below with reference to 0.

FIG. 10 is a diagram showing a scattering SNOM in which a probe and a cantilever are optically opaque. This type of SNOM is described, for example, in Knoll and
F. Keilmann, Science 399 (19
99) p. 134 etc.

In order to maintain a sufficiently close constant distance between the tip of the probe 2 and the surface of the sample 1, an atomic force microscope (hereinafter, AFM: Atomic Force Micror) is used.
In general, the principle of oscilloscope) is used. This is because when the tip of the probe 2 approaches the sample 1, the atomic force acting between the tip of the probe 2 and the sample 1 causes
Utilizing that the cantilever 3 as a holding member bends, by driving the actuator 4 for the probe or the actuator 26 attached to the sample stage between the cantilever 3 and the sample 1 so as to always have a constant amount of bending, the vertical direction is obtained. (DC mode).

The deflection of the cantilever 3 is measured by, for example, a detector 25 using the principle of an optical lever. In addition, by using the probe actuator 4 to vibrate the probe 2 vertically or in a direction substantially parallel to the surface of the sample 1, the amplitude of the tip of the probe 2 changes with the distance from the surface of the sample 1.
By making this constant, the interval control can be performed (AC mode).

The probe 2 is applied so that the central axis is substantially perpendicular to the sample 1, and when the cantilever 3 is installed substantially perpendicular thereto, there is no slip on the surface of the sample 1 and the force can be applied to the cantilever 3 most efficiently. Since it is converted into deflection, distance control can be performed with high sensitivity. However, when the cantilever 3 is installed substantially parallel to the surface of the sample 1, the sample 1 may come into contact with the cantilever 3 itself depending on the unevenness of the sample 1, so that the cantilever 3 is usually inclined by about 10 °.

[0010] Scanning is performed with the tip of the probe 2 approaching the sample 1 by the above-mentioned method.
6 is operated to perform raster scanning in a direction substantially parallel to the surface of the sample 3.

Irradiation of light to the tip of the probe 2 is performed by a light source 16.
This is performed by irradiating light from the vicinity of the tip of the probe 2 by the irradiation optical system 23. The light source 16 emits parallel light by appropriately combining a laser, a xenon lamp, or the like with an expander, a collimator, or the like.

The scattered light from the vicinity of the tip of the probe 2 caused by the light irradiation is condensed by using the condenser lens 97 and the imaging lens 8. By placing the pinhole 14 at the focusing position, light from other than near the tip of the probe 2 is cut,
Light noise from surroundings is reduced. The light that has passed through the pinhole 14 is converted into an electric signal by a photomultiplier tube 15, processed by a computer 17, and displayed on a monitor 18 as a measurement result.

When distance control is performed by vibrating the tip of the cantilever 3 in addition to the pinhole 14, the modulation of light at the tip of the probe 2 by this vibration is used to lock in only the optical signal synchronous component. The S / N ratio is also improved by detecting with the detector.

According to the above-described method, when a substance having a different material is mixed in the sample 1, the amount of scattered light or the like fluctuates. Therefore, the presence thereof can be displayed in the order of the tip diameter of the probe 2.

The objective lens 7 is arranged on the upper part of the sample 1, an image of the upper part of the sample 1 is taken by an image pickup device 99 through an imaging lens 98, and the image is displayed on a monitor 100 for an optical microscope. If you can observe with optical microscope,
The positioning of the probe 2 for SNOM observation becomes easy. A scattering type SNOM having such an ordinary optical microscopic observation means and having an observation system using an appropriately shaped probe 2 so that the objective lens 7 also serves as a condenser lens of the detection system is disclosed in No. 54099.

[0016]

The scattering-type scanning near-field optical microscope described above often uses an opaque probe, and the probe holder is often opaque. When such an opaque probe is used, light is incident obliquely from a separate incident system. Therefore, there are problems that the device becomes large and adjustment of illumination light is complicated.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a scanning near-field optical microscope which is easy to set while reducing cost and size. It is another object of the present invention to provide means for increasing the S / N ratio in such a configuration.

[0018]

A scanning near-field optical microscope according to the present invention, which achieves the above object, comprises a probe having a sharp tip having a tip diameter smaller than the center wavelength of irradiation light, and a probe supporting the probe. A holding member, means for approaching the tip of the probe near the sample from substantially vertically above the sample, means for irradiating light near the tip of the probe including a light source, and a detector including In a light measuring device having means for detecting light, the optical microscopic observation means from substantially vertically above the sample, the optical microscopic observation means includes an objective lens disposed substantially perpendicular to the sample, the probe, Near the focal position of the objective lens, at least one straight line starting from the tip of the probe and having a center wavelength or less as a starting point is at least part of the effective diameter of the objective lens without being blocked by the probe and the probe holding member. You can cross Disposed, the objective lens is characterized in that also serves as a part of the means for irradiating light to the probe tip.

Another scanning near-field optical microscope of the present invention is a probe having a sharp tip having a tip diameter smaller than the center wavelength of irradiation light, a probe holding member for supporting the probe, and the probe tip. Means for approaching the sample near the sample from substantially vertically above the sample, means for irradiating light near the tip of the probe including a light source, and means for detecting light from near the tip of the probe including a detector. In the optical measurement device, the optical microscope has an optical microscopic observation means from substantially vertically above the sample, the optical microscopic observation means includes an objective lens arranged substantially perpendicular to the sample, and the probe is located near the focal position of the objective lens. At least one straight line starting from the tip of the probe and having a center wavelength or less as a starting point is arranged so that it can cross at least a part of the effective diameter of the objective lens without being blocked by the probe and the probe holding member. This objective The device also has a means for irradiating the tip of the probe with light, has a light modulating means using the probe, and the light detecting means includes means for detecting a component synchronized with the modulation. is there.

In these, it is desirable that the means for irradiating the light include means for removing scattering.

In this case, it is desirable that the scattering removing means is a light shielding means which is disposed between the light source and the objective lens and includes an optical axis.

Further, a means having a means for giving a phase distribution to the irradiation light beam cross section may be used.

In this case, a phase difference of a half wavelength can be given to at least two points symmetrical to the optical axis.

In the above description, the incident light is monochromatic light and may be detected as light having a different wavelength from the incident light.

The light having a wavelength different from that of the incident light is, for example, Raman scattering light or luminescence light.

In the above description, the objective lens may also be used as a part of the detecting means.

The detecting means may include a sample reflected light removing means.

In this case, the sample reflected light removing means may be arranged between the objective lens and the detector, and may be a light blocking means for blocking the reflected light on the sample surface.

In this case, means for giving a phase distribution to the cross section of the detection light may be provided.

Then, a phase difference of a half wavelength can be given to at least two points on the section of the detection light symmetrical to the optical axis.

In the above, the scanning means for relatively scanning the sample and the probe, the feedback means for maintaining the probe near the sample, the storage means for storing the result at each point, and the display means for displaying the result are provided. It can be configured to have.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the scanning near-field optical microscope of the present invention will be described below, and then embodiments thereof will be described with reference to the drawings. In the description of each drawing, the same reference numeral indicates an element having a similar function.

(First Embodiment) FIG. 1 shows a first embodiment. Also in this embodiment, the positional relationship of the probe 2 and the cantilever 3 used as a probe holding member with respect to the sample 1 is the same as the configuration described in the related art. However, the present embodiment is characterized in that the observation optical system in the prior art is also used as an illumination optical system.

In this embodiment, the observation optical system in the prior art, that is, the objective lens 7 and the imaging lens 98 for imaging the light flux from the sample 1 made parallel by the objective lens 7 on the image sensor 99 are provided. Since the observation optical system including the optical microscope monitor 100 for displaying the image of the sample 1 captured by the imaging device 99 is also used as the illumination optical system, the half mirror 92 is provided between the objective lens 7 and the imaging lens 98. Is arranged. Thereby, light from the light source device 16 is guided to the objective lens 7. As the light source of the light source device 16,
A laser or a xenon lamp is used. The light source device 16 is provided with an optical system such as an expander and a collimator. The optical system enlarges / reduces the diameter of the light beam so that the light beam emitted from the light source fills the pupil of the objective lens 7.

With the above configuration, the illumination optical system 23 provided separately from the observation optical system in the prior art is provided.
(FIG. 10) becomes unnecessary. Therefore, it is possible to realize an SNOM in which the entire apparatus is compactly configured. Further, the elimination of the illumination optical system increases the free space around the sample 1. Therefore, the detection optical system (condensing lens 97, imaging lens 8, pinhole 14, photomultiplier tube 1)
The degree of freedom when arranging 5 is increased. As a result, for example,
The detection optical system can be arranged at a position where the detection sensitivity is highest.

In the present embodiment, since the illumination is performed via the objective lens 7, the illumination of the tip of the probe 2 is performed from a substantially vertical direction. Here, in order to make the illumination light reach the tip of the probe 2, the present embodiment uses an objective lens 7 having a large numerical aperture. Further, when the probe 2 extends a line connecting the distal end portion of the probe 2 to the base portion (that is, a portion in contact with the cantilever 3) toward the objective lens 7, the extended line corresponds to the effective diameter of the objective lens 7. It has at least a shape that crosses at least a part thereof. In other words, the probe 2 has a numerical aperture determined by the extended line and the optical axis O of the objective lens 7.
It is necessary to have a shape that is smaller than the numerical aperture.

For example, a perspective view seen from below in FIG.
The probe A1 shown in the side view in FIG. 1B is a conventional probe, and has a triangular pyramid shape. Tip A of this probe A1
Since the ridge line L1 is parallel to the optical axis O of the objective lens, for example, the ridge line L1 is parallel to the optical axis O of the objective lens. Reach within the effective diameter. Therefore, of the illumination light emitted from the objective lens 7, the illumination light having a large numerical aperture indicated by an arrow (FIG. 2B) reaches the surfaces A4 and A5 of the probe A1. As a result, detection using scattered light can be performed as in the related art.

Further, as shown in FIG. 3, when the shape of the probe B1 is a cone, a line L2 connecting the tip B2 of the probe B1 to the base B3 is a generatrix of the cone. Therefore,
The angle between the bus L2 and the optical axis O of the objective lens 7 is θ
1. Assuming that the angle determined by the maximum numerical aperture of the objective lens 7 is θ2, if the probe B1 is formed into a conical shape such that θ1 <θ2, the illumination light having a large numerical aperture indicated by an arrow is emitted from the probe B1. Reach the conical surface. Therefore, even with the probe B1 having such a shape, detection using scattered light can be performed as in the related art.

Returning to FIG. 1, the scattered light from the vicinity of the tip of the probe 2 caused by the irradiation of the illumination light is condensed using the condenser lens 97 and the imaging lens 8. By locating the pinhole 14 at the focusing position, signals from areas other than the vicinity of the tip of the probe 2 are cut, and optical noise from the surroundings is reduced. Light passing through the pinhole 14 is converted into a photomultiplier tube 15
Then, only the optical signal component synchronized with the vibration of the tip of the cantilever 3 is detected by the lock-in detector 93, processed by the computer 17, and displayed on the monitor 18 as a measurement result. Since the synchronization signal is detected, an image can be obtained with a better S / N ratio than when no synchronization signal is detected.

According to the above method, only the scattered light at the tip of the probe 2 can be obtained. If the sample 1 is mixed with a different material, the amount of scattered light or the like fluctuates. Its presence can be displayed in the order of the tip diameter.

In addition, the photomultiplier tube 15 is replaced by a spectroscope, and Raman spectrum or luminescence spectrum of scattered light or data of one wavelength among them is stored and displayed corresponding to each point while scanning. Thus, a Raman SNOM or a luminescence SNOM image is obtained. In this case, since unnecessary scattering from the cantilever 3 or the like has a different wavelength and does not affect Raman and luminescence data, an image with a high S / N ratio can be obtained without synchronous detection. If the Raman signal is weak and it takes too much time to obtain a Raman SNOM image, for example, an AFM image or an optical microscope image alone is used to select a region or point of interest, and the actuator 26 scans that region. If a high-resolution image is obtained, a Raman signal is obtained by moving to that point and a Raman signal is obtained. (Second Embodiment) FIG. 4 shows a second embodiment. In the present embodiment, as in the first embodiment, the observation optical system and the illumination optical are integrally configured. However, the present embodiment is characterized in that the light shielding means 106 is disposed between the light source device 16 and the half mirror 92. As shown in FIG. 5, the light shielding unit 106 includes a light shielding unit 101 and an opening 102. The opening 102 is provided at a position eccentric from a position 104 intersecting with the optical axis of the illumination optical system when the light shielding means 106 is arranged in the optical path. In addition, the position of the opening 102 is within the range 1
It is inside from 03.

When such a light shielding means 106 is arranged in the illumination optical system, the illumination light
Only the illumination light passing through the opening 102 enters the objective lens 7. At this time, since the opening 102 is provided at a position decentered from the optical axis of the illumination optical system, the illumination light flux passing through the opening 102 enters a position away from the optical axis O of the objective lens 7. . Therefore, the illumination light emitted from the objective lens 7 becomes a light flux having a large numerical aperture range, that is, a light flux greatly inclined with respect to the optical axis O of the objective lens 7, so that the tip of the probe 2 is irradiated. Can be. In addition, the illumination light other than the illumination light that has passed through the opening 102 is shielded by the light shielding unit 101, so that the cantilever 3 is not illuminated as in the first embodiment. As described above, according to the configuration of the present embodiment, the scattering of the illumination light in the cantilever 3 does not occur, so that a detection with a higher S / N ratio can be performed.

In this embodiment, the light shielding means 106 is used to illuminate only the tip of the probe 2.
6, the same operation as the light shielding means 106 can be realized. For example, a collimator provided in the light source device 16 generates a light beam smaller than the effective diameter of the objective lens 7,
The position of the light source may be adjusted by a stage capable of adjusting the position of the light source so that the light beam enters a position eccentric with respect to the optical axis O of the objective lens 7.

Then, scattered light from the vicinity of the tip of the probe 2 caused by the irradiation of the illumination light is condensed by the condensing lens 97. By locating the pinhole 14 at the focusing position, signals from areas other than the vicinity of the tip of the probe 2 are cut, and optical noise from the surroundings is reduced. Pinhole 1
The light passing through 4 is converted into an electric signal by the photomultiplier tube 15, and only the optical signal component synchronized with the vibration of the tip of the cantilever 3 is detected by the lock-in detector 93, processed by the computer 17, and then measured. The result is displayed on the monitor 18. Since the synchronization signal is detected, an image can be obtained with a better S / N ratio than when no synchronization signal is detected.

By the above method, only the scattering at the tip of the probe 2 can be obtained. If the sample 1 is mixed with a different material, the amount of scattered light or the like fluctuates. Its presence can be indicated in the order of the diameter.

Further, as the light shielding means 106, a light shielding means having a structure as shown in FIG. 6 can be used. The light shielding means of FIG. 6 has two openings 102, which are arranged symmetrically with respect to the axis 104. Then, the phase of the light passing through one of the openings is delayed (or advanced) by λ / 2.
A half-wave plate 105 is provided (λ is a wavelength). With such a configuration, each illumination light that has passed through the opening 102 enters a position decentered from the optical axis O of the objective lens 7 as shown in FIG. Here, the difference in the direction of the arrow in the figure indicates that the polarization direction is the same, but the phase is different. Since each of the illumination lights emitted from the objective lens 7 is a light flux having a large numerical aperture, both of them reach the tip of the probe 2. At the tip of the probe 2, both illumination lights are combined, but at this time, light polarized in a direction along the optical axis is generated. The light polarized in this direction is considered to be the light that has the strongest interaction with the sample 1, and therefore has a higher S
The detection with a high / N ratio becomes possible. Depending on the shape of the tip of the probe 2, other polarized light may be appropriate, but any polarized light can be generated by appropriately changing the phase difference between the apertures. If the light source is a laser, the light is already polarized. However, depending on the light source, a polarization rotating means or a polarization limiting means such as a polarizer may be used in combination.

(Third Embodiment) FIG. 8 shows a third embodiment. The positional relationship between the probe 2 and the cantilever 3 used as a probe holding member with respect to the sample 1 is the same as the configuration described in the related art. The method of scanning the tip of the probe 2 and the surface of the sample 1 so as to maintain a sufficiently close constant distance is the same as in the related art. In this embodiment, distance control in the AC mode is used.

The light from the light source device 16 is guided to the objective lens 7 via the half mirror 92 disposed between the objective lens 7 and the imaging lens 98, and the light is irradiated to the tip of the probe 2 near the tip of the probe 2. Irradiation is performed. The light source device 16 emits parallel light by appropriately combining a laser, a xenon lamp, and the like with an expander, a collimator, and the like.

The scattered light from the vicinity of the tip of the probe 2 caused by the irradiation of light is received by the objective lens 7 again, transmitted through the half mirror 92, and another half mirror 91 disposed between the objective lens 7 and the imaging lens 98. And condensed by the imaging lens 8. With this configuration, a scattering SNOM having a more compact configuration is realized.

The pinhole 14 is located at the converging position of the imaging lens 8.
Is arranged, the portion other than the vicinity of the tip of the probe 2 is cut, and optical noise from the surroundings is reduced. The light that has passed through the pinhole 14 is converted into an electric signal by the photomultiplier tube 15, and only the optical signal component synchronized with the vibration of the tip of the cantilever 3 is detected by the lock-in detector 93 and processed by the computer 17. Monitor 18 as the measurement result.
Will be displayed. Since the synchronization signal is detected, an image can be obtained with a better S / N ratio than when no synchronization signal is detected.

In order to avoid the back surface of the probe 2 placed substantially vertically and the tip of the cantilever 3 near the back of the probe 2, only a portion away from the optical axis O is opened and the remaining portion is shielded from the illumination light incident path. Is placed so as to avoid scattering of light at portions other than the tip of the cantilever 3 and the tip of the probe 2. This configuration has the further effect of improving the S / N ratio.

Further, on the optical path of the detection light, there is provided a light shielding means 107 for avoiding the reflected light of the incident light on the sample surface.
Avoids noise due to reflected light. This further increases S
This has the effect of improving the / N ratio.

With the above arrangement, only the scattering at the tip of the probe 2 can be obtained. If the sample 1 contains a mixture of different materials, the amount of scattered light or the like fluctuates. Its presence can be displayed in the order of the tip diameter.

Further, the light shielding plate 106 having a shape as shown in FIG. 6 is used, and the light shielding plate 106 is appropriately rotated so that the light flux passing through the opening 102 does not hit the cantilever 3 or the like. When the same light-shielding means 107 is used to appropriately rotate the light from the incident-side light-shielding plate 106 so that the reflected light on the sample surface is shielded, light as shown in FIG. Polarized light of opposite directions as shown in FIG. 9 returns to the detection side opening, and only this polarized light component can be selectively detected. This is because one of the polarizations is inverted by the half-wave plate 105, so that they are mutually strengthened on the photomultiplier tube 15. On the other hand, if there is a component polarized in the same plane at the tip of the probe 2, This is because, on the contrary, the half-wave plate 105 cancels out each other. In a probe having an ideal shape, it is considered that polarized light in this direction interacts more strongly with the sample 1 to generate a strong contrast (B. Knolla
ndF. Keilmann, Optics Commu
nications 182 (2000) p. 32
1) This method has the effect of improving the S / N ratio. Probe 2
Depending on the shape of the tip, other polarized light may be appropriate, but any polarized light can be generated by appropriately changing the phase difference between the apertures. If the light source is a laser, the light is already polarized. However, depending on the light source, a polarization rotating means or a polarization limiting means such as a polarizer may be used in combination. If necessary, a polarization limiting means may be provided on the detection side to improve the S / N ratio.

The above-mentioned scanning near-field optical microscope of the present invention can be constituted, for example, as follows.

[1] A probe having a sharp tip with a tip diameter smaller than the center wavelength of irradiation light, a probe holding member for supporting the probe, and the tip of the probe approaching the sample near substantially vertically above the sample. Means for irradiating light near the tip of the probe, including a light source, and means for detecting light from near the tip of the probe, including a detector. Optical microscope observation means, the optical microscope observation means includes an objective lens arranged substantially perpendicular to the sample, and the probe is located near the focal position of the objective lens, and has a tip portion less than the center wavelength from the tip of the probe. At least one of the straight lines starting from is arranged so as to be able to cross at least a part of the effective diameter of the objective lens without being interrupted by the probe and the probe holding member. Part of the means for irradiating A scanning near-field optical microscope, which also serves as a light source.

[2] A probe having a sharp tip having a tip diameter smaller than the center wavelength of the irradiation light, a probe holding member for supporting the probe, and the tip of the probe approaching the vicinity of the sample from substantially vertically above the sample. Means for irradiating light near the tip of the probe, including a light source, and means for detecting light from near the tip of the probe, including a detector. Optical microscope observation means, the optical microscope observation means includes an objective lens arranged substantially perpendicular to the sample, and the probe is located near the focal position of the objective lens, and has a tip portion less than the center wavelength from the tip of the probe. At least one of the straight lines starting from is arranged so as to be able to cross at least a part of the effective diameter of the objective lens without being interrupted by the probe and the probe holding member. Part of the means for irradiating A scanning near-field optical microscope, characterized in that the scanning near-field optical microscope further comprises a light modulating means using a probe, and the light detecting means includes means for detecting a component synchronized with the modulation.

[3] The scanning near-field optical microscope according to the above [1] or [2], wherein the means for irradiating the light includes a scattering removing means.

[4] The scanning near-field optical microscope according to the above item 3, wherein the scattering removing means is a light shielding means including an optical axis, disposed between the light source and the objective lens.

[5] The scanning near-field optical microscope according to the above item 3, wherein the scanning near-field optical microscope has means for giving a phase distribution to the cross section of the irradiation light beam.

[6] At least two points symmetrical to the optical axis
5. The method of claim 5, wherein a phase difference of one-half wavelength is provided.
The scanning near-field optical microscope according to the above.

[7] The scanning near-field optical microscope according to any one of [1] to [6], wherein the incident light is monochromatic light and is detected by light having a wavelength different from that of the incident light.

[8] The scanning near-field optical microscope according to the above item 7, wherein the light having a wavelength different from the incident light is Raman scattering light or luminescence light.

[0064]

[9] The scanning near-field optical microscope according to any one of [1] to [8], wherein the objective lens also functions as a part of a detection unit.

[10] The scanning near-field optical microscope according to any one of the above items 1 to 9, wherein the detecting means includes a sample reflected light removing means.

[11] The scanning device according to the above item 10, wherein the sample reflected light removing means is a light shielding means disposed between the objective lens and the detector, for shielding light reflected on the sample surface. Type near-field optical microscope.

[12] The scanning near-field optical microscope according to the above item 11, wherein the scanning near-field optical microscope has a means for giving a phase distribution to the cross section of the detection light.

[13] The scanning near-field optical microscope according to the above item 12, wherein a phase difference of a half wavelength is given to at least two points of the detection light section symmetrical to the optical axis.

[14] Scanning means for relatively scanning the sample and the probe, feedback means for keeping the probe near the sample, storage means for storing results at each point, and displaying the results 14. The scanning near-field optical microscope according to any one of the items 1 to 13, further comprising a display unit that performs the operation.

[0070]

As is apparent from the above description, according to the present invention, the objective lens constituting a part of the optical microscope unit installed for positioning is used as a part of the incident system, so that the incident system is improved. And the optical microscope unit to reduce costs,
It is possible to provide a scanning near-field optical microscope that is easy to set while achieving downsizing, and has a high S /
A scanning near-field optical microscope having an N ratio can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a scanning near-field optical microscope according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining that scattered light can be detected by a triangular pyramid-shaped probe according to the principle of the present invention.

FIG. 3 is a diagram for explaining that scattered light can be detected by a cone-shaped probe according to the principle of the present invention.

FIG. 4 is a diagram showing a configuration of a scanning near-field optical microscope according to a second embodiment of the present invention.

FIG. 5 is a view showing one shape of a light shielding means used in the present invention.

FIG. 6 is a view showing the shape of another light shielding means used in the present invention.

FIG. 7 is a diagram illustrating a state of polarization of illumination light when the light shielding unit of FIG. 6 is used.

FIG. 8 is a diagram showing a configuration of a scanning near-field optical microscope according to a third embodiment of the present invention.

FIG. 9 is a diagram illustrating a state of polarization of illumination light and detection light when the light shielding unit of FIG. 6 is used.

FIG. 10 is a diagram showing a configuration of a conventional scanning near-field optical microscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sample 2 ... Probe 3 ... Cantilever 4 ... Actuator (for probe) 6 ... Controller 7 ... Objective lens 8 ... Imaging lens (detection system) 14 ... Pinhole 15 ... Photomultiplier tube 16 ... Light source (light source device) 17 ... Computer 18 ... Monitor 23 ... Irradiation optical system 25 ... Detector 26 ... Actuator (for sample stage) 91 ... Half mirror (detection side) 92 ... Half mirror (irradiation side) 93 ... Lock-in detector 97 ... Condenser lens ( Detection system) 98 imaging lens 99 imaging device 100 optical microscope monitor 101 light blocking unit 102 opening 103 103 range of illumination light flux 104 position (axis) intersecting with the optical axis 105 1/2 wavelength plate 106 ... Light-shielding means (light-shielding plate: irradiation side) 107. Light-shielding means (light-shielding plate: detection side) O. Optical axis of objective lens A1. Probe A2 ... Probe tip A3. Probe base A4, A5. Probe face B1. Probe B2. Probe tip B3. Probe base L1.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2F065 DD02 DD04 FF49 GG03 GG04 GG22 HH13 JJ03 JJ26 LL00 LL04 LL09 LL30 LL33 LL35 MM03 MM07 NN05 NN08 PP24 QQ04 QQ24 SS02 SS13 2H052 AA07 AC30 AC09

Claims (3)

[Claims] 1. A probe having a sharp tip with a tip diameter smaller than the center wavelength of irradiation light, a probe holding member for supporting the probe, and bringing the tip of the probe closer to the vicinity of the sample from substantially vertically above the sample. A light measuring device having means for irradiating light near the tip of the probe including a light source, and means for detecting light from near the tip of the probe including a detector. Optical microscope observation means includes an objective lens arranged substantially perpendicular to the sample, and the probe has a tip near the focal point of the objective lens, which is less than the center wavelength from the tip of the probe. At least one of the straight lines as the starting point
The book is arranged so that it can cross at least a part of the effective diameter of the objective lens without being blocked by the probe and the probe holding member, and the objective lens forms a part of a means for irradiating the tip of the probe with light. A scanning near-field optical microscope characterized by also serving as a near-field optical microscope. 2. The scanning near-field optical microscope according to claim 1, wherein the means for irradiating the light includes a scattering removing means. 3. The scanning near-field optical microscope according to claim 2, further comprising means for giving a phase distribution to a cross section of the irradiation light beam.