JP4498081B2 - Scattering near-field microscope and measuring method thereof - Google Patents

Description

The present invention generates an evanescent field on the sample surface, brings the probe close to or in contact with the sample surface, scatters the evanescent field at the probe tip, and detects the scattered light with a photodetector, thereby achieving a resolution exceeding the diffraction limit. The present invention relates to a scattering near-field microscope for measuring local optical characteristics of a sample surface and a measuring method thereof.

  An apparatus configuration of a conventional scattering near-field microscope is shown in FIG. 7 (see, for example, Non-Patent Document 1).

  In the prior art of FIG. 7, a cantilever 101 for an atomic force microscope having a sharpened probe 102 at the tip and coated with silver having a thickness of 40 nm is used.

  In addition, an oil immersion objective lens 106 with a numerical aperture of 1.4 is arranged behind the measurement surface of the sample 104 via oil immersion oil 105, and an annular shape is formed in a region where the numerical aperture of the oil immersion objective lens 106 exceeds 1.0. Of the evanescent field is formed on the surface of the sample 104.

  The annular laser beam is formed by emitting laser beam from the laser light source 108, expanding the diameter of the laser beam by the beam expander 110, and blocking the light at the central portion of the laser beam 109 by the mask 111, and the half mirror 112 As a result, the optical path is bent 90 degrees and guided to the oil immersion objective lens 106.

  At this time, the laser beam 109 is incident on the objective lens 106 so that the image of the mask 111 is formed on the pupil portion of the oil immersion objective lens 106 by the two lenses 113 and 114, thereby forming a spot of the evanescent field on the sample surface. Let

  Next, the interatomic force acting between the probe 102 and the surface of the sample 104 is detected by the displacement of the cantilever 101, and the Z fine movement mechanism 115 arranged on the probe side so that the interatomic force is constant is used between the probe 102 and the sample 104. The probe 102 is brought into contact with a spot by the evanescent field on the surface of the sample 104 while performing the distance control.

  At this time, the spot of the evanescent field is scattered by the tip of the probe 102. The scattered light is collected by the same oil immersion objective lens 106 used for excitation. When condensing, not only the part having a numerical aperture of 1.0 or more, but also a part having a numerical aperture of 1.0 or less is used.

  In this prior art, rhodamine 6G which is a kind of pigment is measured as a sample. At this time, in the scattered light from the sample, Raman scattered light is generated in addition to Rayleigh scattered light having the same wavelength as the excitation light.

  Here, surface plasmon is excited on the surface of silver coated on the probe 102, and when the sample 104 and silver at the tip of the probe 102 are brought into contact, so-called surface enhanced Raman scattering (SERS: Surface Enhanced Raman Scattering) occurs, It becomes possible to enhance Raman scattered light.

  These scattered light is collected by the oil immersion objective lens 106, the Rayleigh scattered light is removed by the notch filter 116, imaged on the slit 119 of the spectroscope 118 by the imaging lens 117, and dispersed by the spectroscope 118. A local Raman spectrum can be obtained by measuring with a liquid nitrogen cooled CCD 120 and measuring the spectral spectrum.

  In addition, while the distance between the sample 104 and the probe 102 is controlled by the Z fine movement mechanism 115, the XY fine movement mechanism 121 that scans the sample arranged on the sample side in a two-dimensional plane is raster-scanned, and the avalanche attached to the spectroscope By measuring the Raman scattered light intensity with a photodiode (APD) 122 and corresponding to the operation of the XY fine movement mechanism 121, the intensity distribution in the XY plane is displayed on a monitor (not shown) on the computer 123. It is also possible to measure the intensity distribution of Raman scattered light in the sample plane.

  The liquid nitrogen cooled CCD 120 and the spectroscope 118 are controlled by a controller 124, the XY fine movement mechanism 121, the Z fine movement mechanism 115, and a displacement detection unit (not shown) of the cantilever 101 are controlled by a controller 125, and these operations are performed by a computer. Controlled on 123. The avalanche photodiode 122 outputs a pulse signal corresponding to the detected photon, the number of pulses is counted by the photon counter 126, converted to an analog signal by the digital / analog converter 127, amplified by the amplifier 128, and then on the computer. Displayed on a monitor (not shown).

  Here, since the laser beam is incident with linearly polarized light, the spot of the evanescent field formed on the sample surface by the oil immersion objective lens 106 is perpendicular to the sample surface (P-polarized light) and parallel to the sample surface ( S-polarized light is included, and a plurality of different spots are formed for each polarization component. Of these, the surface-enhanced Raman scattering effect is obtained only for the P-polarized light component, and it is necessary to align the tip of the probe 102 and the measurement site of the sample 104 with the spot of the evanescent field formed by the P-polarized light.

  In this prior art, the probe 102 is brought close to the spot position of the evanescent field on the surface of the sample 104, and the spot of the evanescent field observed by the oil immersion objective lens 106 and the shadow of the probe 102 are observed on the monitor 133 of the oil immersion objective lens 106. Align with the image, and observe the tip of the probe 102 from the lateral direction with a microscope with respect to the central axis of the probe 102 (the microscope is not shown), and the Rayleigh scattered light at the tip of the probe 102 is the strongest by the observation image of the microscope The probe 102 is aligned with the observed position, and then the sample 104 is scanned by the XY fine movement mechanism 121 on the sample side.

Note that the observation of the probe 102 and the evanescent field spot by the oil immersion objective lens 106 is performed by arranging the half mirror 130 in the optical path, bending the optical path by 90 degrees, and forming an image on the observation CCD camera 132 by the imaging lens 131. The observation image of the CCD camera is displayed on the monitor 133.
Norihiko Hayazawa, Yasushi Inouye, Zouheir Sekkat, Satoshi Kawata, Near-field Raman imaging of organic molecules by an apertureless metallic probe scanning optical microscope, Journal of Chemical Physics, Vol.117, No.3, 15 July 2002, 1296-1301, (Fig.2, Fig3)

  However, the method of checking Rayleigh scattered light at the tip of the probe by visual observation or optical microscope observation as in the prior art decreases the accuracy of alignment between the probe and the evanescent field spot, and high scattering efficiency cannot be obtained. A sufficient amount of light as a microscope could not be obtained.

  In other words, the size of the evanescent field spot is usually several hundred nm or less in the XY plane, and there is an intensity distribution in the spot. It is necessary to obtain high scattering efficiency by accurately aligning both the probe and the sample in a strong place.

  Further, since the intensity of the evanescent field spot in the optical axis direction is exponentially attenuated in the region of about 100 nm, it is necessary to precisely perform spot focusing.

  Further, when the tip of the probe of the cantilever is observed with a microscope, the cantilever becomes a shadow. Therefore, in order to observe the tip of the probe, it is necessary to dispose the objective lens at a shallowest angle. In this case, it is necessary to observe the probe floating in the space with an optical microscope, the optical microscope image is dark, and it is difficult to observe the probe, and it takes a lot of time to find the probe.

  Further, when the cantilever type probe is observed from the lower side of the sample, it is difficult to confirm the probe tip because the probe tip and the cantilever image overlap, and it is difficult to align the spot of the evanescent field and the probe tip.

  The object of the present invention is to accurately and easily position the probe and the sample at a place where the intensity of the spot of the evanescent field formed on the sample surface is maximum in the XY plane and the Z direction, thereby achieving high scattering efficiency. And a measurement method of a scattering near-field microscope that achieves high resolution with a sufficient amount of light.

In order to solve the above problems, in the measuring method of the scattering near-field microscope of the present invention, an evanescent field generating means for generating an evanescent field on the sample surface, and a probe for scattering the evanescent field by approaching or contacting the sample surface And a Z fine movement mechanism for controlling the distance between the probe and the sample when the XY axis is taken in the sample plane and the direction perpendicular to the sample surface is the Z axis, and the probe and the sample are relatively sampled. XY fine movement mechanism moved in the plane, scattered light collecting means for collecting the scattered light scattered by the probe, a photodetector for measuring the intensity of the scattered light, and detected by the photodetector In a scattering near-field microscope having at least a display device that displays intensity,
While keeping the distance between the probe and the sample surface constant by the Z fine movement mechanism, the probe scans an area including an evanescent field generated on the sample surface by the XY fine movement mechanism provided on the probe side, The scattered light scattered by the probe is collected by the scattered light collecting means, the scattered light intensity is measured by the photodetector, the scattered light intensity is displayed by the display device, and the intensity of the evanescent field is displayed from the display result. The distribution is obtained, and the probe is positioned by the XY fine movement mechanism in the portion where the intensity of the evanescent field is maximized.

  Further, the evanescent field generating means includes an optical system for condensing the light on the sample surface by the lens, the lens is provided with a focusing mechanism, the Z fine movement mechanism is provided on both the sample and the probe, and the focal point of the lens is focused on the sample surface. XY fine movement mechanism on the probe side at the part where the intensity of the evanescent field in the XY plane is maximized while focusing by the mechanism and controlling the distance between the probe and the sample surface by the Z fine movement mechanism on either the probe side or the sample side After positioning the probe, move the other Z fine movement mechanism in the Z-axis direction, measure the scattered light intensity at that time, display the scattered light intensity on the display device, and display the evanescent in the Z-axis direction from the display result. Obtain the intensity distribution of the field, and place the two Z in the part where the intensity of the evanescent field is maximum. The rotation mechanism for positioning the probe and the sample.

  In the scattering near-field microscope of the present invention, in a scattering near-field microscope using a cantilever having a probe at the tip, a line connecting the probe tip and the side edge of the cantilever with the sample surface as a reference plane When the angle formed by the surface is θ, an objective lens for observing the probe tip is arranged so that the optical axis is in the range of 0 ° to 0 °, and the tip of the probe is irradiated with illumination light from the objective lens side. And a reflecting plate was provided on the optical axis conjugate with the optical axis of the objective lens with respect to the probe tip so that the scattered light at the probe tip could be observed.

  Further, in the scattering near-field microscope of the present invention, in the scattering near-field microscope using a cantilever having a probe at the tip, an objective lens is provided on the side facing the probe with respect to the sample, and the evanescent field of the sample is provided by the objective lens. Observe the image of the spot and the probe, irradiate the illumination light obliquely above the cantilever with respect to the optical axis of the objective lens, and the shadow of the probe tip reflected in the observation image by the objective lens is in the XY plane. It was made to observe so that it might not overlap with a shadow.

  In the measuring method of the scattering near-field microscope configured as described above, the region including the evanescent field generated on the sample surface is scanned with the probe while the distance between the probe and the sample surface is kept constant, and the probe is scattered by the probe. The scattered light intensity is displayed, the intensity distribution of the evanescent field is obtained from the display result, and the probe is positioned at the portion where the intensity of the evanescent field is maximum.

  By positioning the probe in this way, the tip of the probe can be reliably and easily aligned with the strongest part of the spot in the evanescent field, improving the scattering efficiency and improving the intensity of the detection signal. It becomes possible to make it.

  In addition, after positioning the probe at the strongest portion in the spot of the evanescent field, the sample was positioned at the probe tip by an XY fine movement mechanism arranged on the sample side. By positioning the sample in this manner, the position of the sample to be measured can be easily and reliably positioned.

  In addition, the Z fine movement mechanism is provided on both the sample and the probe, and the distance between the probe and the sample surface is controlled by the Z fine movement mechanism on either the probe side or the sample side, while the other Z fine movement mechanism is operated in the Z direction. Then, the scattered light intensity at that time was measured, and the focusing position of the lens that created the spot of the evanescent field was adjusted based on the measured data. In another embodiment, a Z fine movement mechanism is provided in the lens focusing mechanism, the fine movement mechanism for focusing is operated, the scattered light intensity at that time is measured, and the focusing position of the lens is adjusted based on the measurement data.

  By adjusting the focusing in this way, it is possible to easily and reliably align the probe tip and the sample measurement location at the highest intensity part in the depth direction of the evanescent field spot, and the scattering efficiency is improved. It is possible to improve the strength of the detection signal.

  One or more of an XY fine movement mechanism or Z fine movement mechanism provided on the probe side, an XY fine movement mechanism or Z fine movement mechanism provided on the sample side, and a focusing Z fine movement mechanism provided on the objective lens A displacement detection mechanism is provided in the fine movement mechanism to measure with a scattering near-field microscope.

  By providing the displacement detection mechanism in this manner, the position reproducibility and positioning accuracy of each fine movement mechanism can be improved, and further, drift after positioning can be suppressed.

  Also, observe the probe from the side with the objective lens, and place the reflector on the optical axis conjugate with the optical axis of the objective lens, and illuminate the illumination from the objective lens side. I tried to observe. By providing the reflection plate in this manner, it is possible to clearly observe the state of the probe tip, and it is possible to easily align the probe tip with the spot of the evanescent field while observing the scattered light at the probe tip.

  In addition, illumination light is irradiated from obliquely above the cantilever so that the shadow of the probe tip reflected on the objective lens arranged on the side facing the probe with respect to the sample does not overlap the shadow of the cantilever in the XY plane. As a result, the position of the probe tip can be reliably recognized, and the probe tip can be easily aligned within the spot of the evanescent field.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an overview of the apparatus configuration for a scattering near-field microscope according to the first embodiment of the present invention. In the following description, the vertical direction of the paper surface is the Z axis, the horizontal direction is the X axis, and the direction perpendicular to the paper surface is the Y axis.
In this embodiment, a scanning probe microscope cantilever 1 integrally formed of silicon having a probe 2 sharpened at the tip is used. In this cantilever 1, silver is deposited on the surface in order to enhance the Raman scattered light by using the surface enhanced Raman scattering to improve the scattering efficiency.

  The cantilever 1 is fixed to a cantilever holder 4, and the cantilever holder 4 is fixed to an optical lever type displacement sensor 5 for detecting the displacement of the cantilever. The displacement sensor 5 condenses the semiconductor laser light 6 with a condensing lens 7, bends the optical path with a mirror 8 and irradiates the back surface of the cantilever 1, receives the reflected light from the cantilever 1 with the mirror 9, and has a light receiving surface of 4 The intensity of the laser beam is detected by the divided photodetector 10. At this time, the laser spot on the photodetector 10 moves in the Z-axis direction according to the vertical deflection of the cantilever 1. At this time, it is possible to detect the displacement of the cantilever 1 by taking a difference in intensity between the upper two detector surfaces and the lower two detector surfaces of the photo detector 10 divided into four.

  The displacement sensor 5 and the cantilever holder 4 are fixed to a triaxial fine movement mechanism 14 on the probe side. The three fine movement mechanism 14 is configured by combining three fine movement mechanisms, that is, an X-axis fine movement mechanism 11, a Y-axis fine movement mechanism 12, and a Z-axis fine movement mechanism 13 that are driven by a multilayer piezoelectric element. The fine movement mechanisms 11, 12, and 13 of each axis incorporate displacement detectors composed of capacitance sensors 15, 16, and 17, respectively, and a voltage is applied to the piezoelectric element in accordance with the displacement commanded from the control device 18. Closed loop control is performed to be applied. The triaxial fine movement mechanism 14 is fixed on a manual XY stage 19, and the XY stage 19 is placed on a measurement head 20.

  The measuring head 20 is provided with a coarse movement mechanism 23 composed of a stepping motor 21 and a feed screw 22 and two micrometers 24 and 25 installed in a direction perpendicular to the paper surface of the figure. 3 points, the tips of the micrometers 24 and 25, are mounted on the base 26. When the feed screw 22 is moved in the Z-axis direction by the coarse movement mechanism 23 in this state, the tip of the probe 2 is moved in the Z-axis direction with the tips of the micrometers 24 and 25 as fulcrums. Here, the movement of the tip of the probe 2 is strictly an arc motion, but can be approximately regarded as a linear motion in the Z-axis direction.

  On the other hand, the sample 28 is placed on a sample holder 29 provided at a position facing the probe 2. Further, the sample holder 29 is fixed to a sample side triaxial fine movement mechanism 30. The triaxial fine movement mechanism 30 is provided with an opening serving as an optical path at the center, and is driven by a laminated piezoelectric element. In addition, a displacement detector comprising a capacitance sensor (not shown) is also provided inside the triaxial fine movement mechanism 30, and closed-loop control is performed so that a voltage is applied to the piezoelectric element according to the commanded displacement. Done.

  While controlling the distance by the Z fine movement mechanism 13 on the probe 2 side, the surface of the sample 28 is scanned in the XY plane by the three fine movement mechanism 30 on the sample side, thereby measuring an uneven image on the surface of the sample 28, and a computer 51 It is possible to display on a monitor (not shown) connected to. A series of these operations is performed by the control device 18 and the computer 51.

  Next, an evanescent field generating mechanism 31 for generating an evanescent field on the surface of the sample 28 will be described. The evanescent field generating mechanism 31 includes a laser light source 32 having a wavelength of 532 nm, a λ / 2 wavelength plate 33, a beam expander 34, two lenses 35a and 35b, a mask 36, a non-polarizing beam splitter 37, and an oil immersion objective lens 38. Composed.

  First, the beam diameter of the laser light 39 emitted from the laser light source 32 fixed so as to have vertical polarization in the vertical direction (Z-axis direction) in the drawing is expanded by the beam expander 34. Next, the mask 36 is provided between the two lenses 35a and 35b, and the optical path in which the two lenses 35a and 35b are arranged so that the image of the mask 36 is formed on the pupil plane of the oil immersion objective lens 38. The laser beam passes through. By expanding the beam by the beam expander 34, a region having a high intensity near the center of the laser light having a Gaussian distribution can be used. Then, the laser light is bent by the non-polarizing beam splitter 37 and guided to the oil immersion objective lens 38.

  Instead of the non-polarizing beam splitter 37, it is also possible to use a half mirror that can be used for a wider range of wavelengths at a lower cost and a dichroic mirror that has an efficient reflection characteristic for wavelengths in a specific region. it can. When a half mirror or a dichroic mirror is used, the reflectance may have polarization dependency. In the case of polarization dependence, a λ / 2 wavelength plate 33 is inserted in front of the laser 32, and the polarization plane is rotated by 90 ° to convert it into polarized light in the Y-axis direction.

  The oil immersion objective lens 38 is an objective lens having a numerical aperture (NA) of 1.4, and is disposed on the lower surface of the sample 28 via the oil immersion oil 41. The oil immersion objective lens 38 is provided with a focusing mechanism (not shown) that operates in the optical axis direction (Z-axis direction) for focusing adjustment, and the oil immersion objective lens is focused on the sample surface 28. 38 position is adjusted.

  An annular laser beam is incident on a region where the NA of the oil immersion objective lens 38 is 1.0 or more, whereby an evanescent field spot is formed on the sample surface 38. The shape of the mask 36 is such that the center of the laser beam is shielded by a circular mask so that an annular laser beam is formed in such a size that the laser beam having an NA of less than 1.0 is blocked and a laser beam of 1.0 or more can be incident. It is a shape to do.

  Next, the collection of scattered light will be described. In this example, a sample 28 in which carbon nanotubes are fixed on a cover glass is measured. When an evanescent field is excited on the carbon nanotube, Raman scattered light from the carbon nanotube is generated in addition to Rayleigh scattered light. By analyzing the Raman scattered light, the physical properties of the carbon nanotube can be known.

  The probe 2 is inserted into the evanescent field spot, and the evanescent field spot is scattered by the probe tip 2. In the near-field microscope of this example, the coarse motion mechanism 23 brings the probe 2 and the sample 28 close to the region where the interatomic force acts, and the deflection of the cantilever 1 due to the interatomic force is detected by the displacement sensor 5, and the amount of deflection is The distance is controlled so that the distance between the probe 2 and the sample 28 is constant by the Z fine movement mechanism 13 provided on the probe side so as to be constant.

  The scattered light scattered by the probe tip 2 is collected by an oil immersion objective lens 38 similar to that used for the evanescent field generation mechanism 31. In this case, light is collected including a portion where NA is 1.0 or less. In addition to the Raman scattered light from the carbon nanotube that is the object to be measured, the Rayleigh scattered light having the same wavelength as the laser light used for excitation is simultaneously collected as the scattered light collected at this time.

  The collected scattered light passes through the non-polarizing beam splitter 37, the optical path is bent by the total reflection mirror 45, the Rayleigh scattered light is removed by the notch filter 46, and the image is formed on the slit of the spectroscope 48 by the imaging lens 47. Is done. The total reflection mirror 44 is removed from the optical path during measurement. The Raman scattered light incident on the spectroscope 48 is dispersed by the control device 50, the light intensity is detected by the liquid nitrogen cooled CCD 49, and the spectrum is displayed on a monitor (not shown) connected to the computer 51.

  The intensity of the dispersed light is detected by an avalanche photodiode (APD) 52, and the surface of the sample 28 is scanned in the XY plane by the triaxial fine movement mechanism 30 on the sample side while keeping the distance between the sample 28 and the probe 2 constant. At this time, by displaying the intensity distribution detected by the APD 52 on a monitor (not shown) connected to the computer 51, it is also possible to perform imaging measurement of Raman scattered light in the sample plane.

  Here, in this example, the probe 2 having a tip coated with silver was used. When such a probe 2 with a silver coat is used, it is possible to enhance the Raman signal using surface enhanced Raman scattering (SERS).

SERS is a phenomenon in which the Raman scattering cross section on the metal surface is enhanced by about 10 ⁵ to 10 ¹⁰ times. This enhancement occurs due to electronic excitation (surface plasmons) on the metal surface. Raman scattered light is generally very weak, and in the case of excitation by evanescent light, the scattered light rate is further deteriorated, and in many cases it is impossible to detect Raman scattered light due to increased noise components. Due to the enhanced electric field, the signal intensity of the Raman scattered light can be improved.

  When performing SERS, only the P-polarized component of the light used for excitation contributes to SERS. Here, FIG. 2 shows a simulation result of the spot shape of the evanescent field of the P-polarized component (perpendicular to the sample plane) and the S-polarized component (horizontal to the sample plane) on the sample surface in Example 1.

  FIG. 2A shows an evanescent field spot of the P-polarized component in the XY plane, and FIG. 2B shows an evanescent field spot of the S-polarized component.

  As can be seen from FIGS. 2 (a) and 2 (b), in the P-polarized light component, two elliptical spots each having a size of about 100 nm to 200 nm are used, and in the S-polarized light component, the same ellipse size having a side of about 100 nm to 200 nm is used. One spot appears. In addition, the intensity distribution of these spots is not uniform, and has a distribution having a peak in each spot.

Also, the intensity of the evanescent field in the Z-axis direction has an intensity distribution that decreases exponentially as the distance from the sample is within a range of about 100 nm from the sample surface.
Therefore, in order to generate SERS efficiently, it is necessary to position the probe tip and the measurement site of the sample with respect to each axis of XYZ at the highest intensity position in the spot of the P-polarized light component.

  Here, the procedure for positioning the probe 2 in the evanescent field will be described with reference to the flowchart of FIG. 3 and FIG.

(1) Spot and probe confirmation The spot of the evanescent field on the surface of the sample 28 and the cantilever 1 are confirmed by an optical image by the oil immersion objective lens 38.
In order to confirm the spot, a total reflection mirror 44 is inserted in the optical path, and an image is formed on the CCD camera 53 by the imaging lens 52, and the image of the CCD camera is displayed on the monitor 54. The probe 2 and the sample 28 are brought close to each other by the coarse movement mechanism 23. At this time, while observing the image of the monitor 54, the position of the probe 2 is adjusted by the XY stage 19 so that the shadow of the cantilever 1 enters the field of view.
(2) Alignment of spot and probe In the monitor confirmation in the state of (1), the shadow of the probe 2 and the shadow of the cantilever 1 appear to overlap. Therefore, illumination is turned on from the diagonally upper side of the sample 28. FIG. 4 is a schematic view showing the illumination method at this time, FIG. 4 (a) is a plan view, and FIG. 4 (b) is a front view.

As shown in FIG. 4, illumination 58 is incident from obliquely above cantilever 1. At this time, illumination is made to enter the gap between the optical lever displacement sensor 5 and the sample 28 shown in FIG.
When illumination light is entered as shown in FIG. 4, the probe image can be confirmed without overlapping the cantilever image.

  In this state, the tip of the probe 2 is aligned with the position of the spot image in the evanescent field while viewing the image on the monitor 54. When alignment is performed, the probe 2 and the sample 28 are brought close to or in contact with the region where the interatomic force is applied, and the distance is controlled by the probe side Z fine movement mechanism 13, while the probe side XY fine movement mechanisms 11 and 12 are offset. Move by applying voltage. Although it is possible to perform alignment using the manual XY stage 19, there is a high possibility that the tip of the probe 2 will be broken by vibration caused by touching the XY stage 19, and compared to the XY fine movement mechanisms 11 and 12. The positioning accuracy is also low, and it is difficult to perform positioning on the spot with the manual type XY stage 19.

In the alignment by the XY fine movement mechanisms 11 and 12, since the distance feedback is always applied by the Z fine movement mechanism 13, the alignment can be performed without damaging the probe 2.
Note that when the power of the laser beam is strong, the spot image may appear to spread over the entire screen of the monitor 54, making it difficult to confirm the center position. In such a case, an ND filter is inserted in the optical path of the evanescent field generating mechanism 31 so that the intensity of the excitation light is weakened for alignment. After completion of alignment by the monitor 54, the total reflection mirror 44 is removed from the optical path.

(3) Confirmation of scattered light at probe tip Next, the spot of the probe 2 tip and the evanescent field are more precisely aligned while confirming the Rayleigh scattered light at the probe tip using an optical system as shown in FIG. .
FIG. 5 is a schematic view of the scattered light checking optical system 59 when the tip of the probe 2 is viewed from the X-axis direction of FIG.

  When the angle formed by the sample surface and the line connecting the tip of the probe 2 and the edge 1a of the side surface of the cantilever 1 with the surface of the sample 28 as the reference surface is θ, the optical axis is in the range of 0 ° or more and θ ° or less. An objective lens 60 for observing the probe tip is arranged so as to enter, and the tip of the probe 2 is observed. When the angle of the optical axis of the objective lens 60 is greater than θ degrees, the cantilever 1 becomes a shadow and the tip of the probe 2 cannot be observed.However, by placing the objective lens 60 as in this embodiment, the tip of the probe 2 Observation becomes possible.

Since the optical lever type displacement sensor 5 shown in FIG. 1 is located above the cantilever 1 and is observed using the gap between the sample 28 and the displacement sensor, the visual field is not obstructed by the displacement sensor.
Here, when observing the tip of the probe 2 with the objective lens 60, it is necessary to observe the cantilever 1 that is floating in the air, so it is very difficult to find the cantilever 1 with the objective lens 60, and the alignment is performed. Even if it is possible, the size of the target probe 2 is about several μm at most, and sufficient reflected light does not enter the objective lens 60, so that observation is often difficult.

  Therefore, a reflector 61 is provided perpendicular to the optical axis on the optical axis conjugate with the optical axis of the objective lens 60 with respect to the tip of the probe 2, an illuminating device 62 is attached on the objective lens 60 side, and illumination is performed by the half mirror 63. By observing the tip of the probe 2 while illuminating illumination light from the objective lens 60 side, the illumination light is reflected by the reflector 61 to obtain a sufficient amount of light, and the probe 2 is clearly observed. It becomes possible. Here, the reflector 61 used a retro reflector. By using the retro reflector, even if the installation angle of the reflection plate is shifted with respect to the optical axis, the reflected light is reflected in the direction of the incident optical axis of the illumination, so that the installation angle of the reflection plate can be easily adjusted. In addition, you may install a total reflection mirror instead of a retro reflector.

  In the scattering near-field microscope, a sufficient space cannot be provided in the periphery of the probe 2, but in the method of the present invention, only the reflector 61 is installed, so the optical system 59 for confirming scattered light can be assembled even in a narrow space. Can do.

  Using this scattered light confirmation optical system 59, while observing with the objective lens 60, the entire scattered light confirmation optical system 59 is connected to the probe 2 by an XY stage and a focusing stage (not shown) of the objective lens 60. Align so that the spot of the evanescent field can be observed. As an observation image, an image of the objective lens 60 is formed on the CCD camera 65 by the imaging lens 64, and the image of the CCD camera 65 is displayed on the monitor 66.

  At this time, a real image of the cantilever 1 and a shadow and spot image of the cantilever 1 reflected on the sample surface are observed on the monitor.

  In this state, an offset voltage is applied to the probe-side XY fine movement mechanisms 11 and 12 while the distance between the probe 2 and the sample 28 is controlled by the probe-side Z fine movement mechanism 13. When the probe comes on the spot, it is observed that the spot of the evanescent field is scattered at the tip of the probe 2 and brightly shines on the monitor. The probe tip is positioned by searching for this position.

  If it is difficult to confirm the scattered light of the spot, once the mask 36 is removed from the optical path and a spot is formed on the sample 28 including the far field component, and the spot is scattered, the probe 2 and the sample 28 are separated. Even if it is, the position of the spot can be recognized, and since the scattered light from the probe 2 is bright, it can be easily aligned. As described above, after first roughly aligning with far-field light, the mask 36 may be placed in the optical path and more precisely aligned with the spot of the evanescent field.

  Here, as described above, a total of three spots including two P-polarized light and one S-polarized light are formed as the spots of the evanescent field. Therefore, when the XY fine movement mechanisms 11 and 12 are moved, three places where scattered light shines strongly are generated. One of them is an S-polarized component, so SERS is not induced, and the intensity is smaller than the other two. Therefore, the probe is positioned at one of the two places having high strength.

  In FIG. 5, the direction observed with the objective lens 60 is not limited to the YZ plane, and may be observed from any direction as long as it is within the angle θ degree described above. Moreover, if it observes from two directions, alignment will become still easier.

(4) Imaging measurement of the evanescent spot In the state of (3), the probe 2 is positioned within the spot of the evanescent field. As described above, since the spot of the evanescent field has an intensity distribution, It is necessary to perform further positioning to a higher position.

  Therefore, while controlling the distance between the probe 2 and the sample 28 by the probe side Z fine movement mechanism 13, a raster scan is performed by the probe side XY fine movement mechanisms 11 and 12, and the scattered light intensity scattered by the probe 2 at that time is measured by the spectrometer. Detection is performed by an avalanche photodiode (APD) 52 attached to 48 and intensity mapping is performed by a monitor (not shown) connected to the computer 51. These operations are performed by the control device 18 of the triaxial fine movement mechanism 14, the control device 50 of the spectroscope 48, and the computer 51 that comprehensively controls them.

  Here, the intensity of the evanescent field depends on the distance from the surface of the sample 28, but since the distance feedback between the probe 2 and the sample 28 is applied, the true intensity mapping is not affected by the distance from the sample surface. Is possible.

  The scattered light detected at this time removes the notch filter 46 and detects the component of the Rayleigh scattered light having the same excitation wavelength.

  In this example, the mask 36 was placed in the optical path, and intensity mapping was measured using only the evanescent component. When measuring Rayleigh scattered light using only the evanescent field component, the intensity of the detection signal is detected as much as the amount scattered by the tip of the probe 2. That is, the highest intensity portion in the intensity mapping is the portion where the intensity of the evanescent field spot is the highest.

  It is also possible to perform measurement including the far field component by removing the mask 36. The Rayleigh scattered light detected in this case is detected with a weak detection signal by the amount scattered by the probe tip. That is, the lowest intensity spot in the intensity mapping is the highest intensity spot of the evanescent field.

(5) Positioning of the probe by the probe side XY fine movement mechanism Based on the intensity mapping image measured in (4), the probe side XY fine movement at the peak position of the intensity of the evanescent field spot 42, that is, the position where the intensity is highest on the intensity mapping image. The probe 2 is positioned by the mechanisms 11 and 12.

  At this time, by designating the strongest place in the intensity imaging image in the XY plane of the evanescent field displayed on the monitor of the computer 51 (not shown), the probe 2 is automatically sent from the control device 18 to the computer. Positioned by the probe-side XY fine movement mechanisms 11 and 12 at a location designated by 51 monitors.

(6) Adjustment of focusing Focusing is adjusted to a substantially focal position by a focusing mechanism (not shown) attached to the oil immersion objective lens 38. As described above, the spot of the evanescent field is about 100 nm in the height direction. Since there is an intensity distribution between them, the positioning is performed more precisely. With the probe 2 approaching the spot of the evanescent field of the sample 28, while measuring the Rayleigh scattered light intensity at the probe tip 2, the offset voltage is applied to the Z-side fine adjustment mechanism 30 on the sample side by the control device 18 Move in a direction perpendicular to the surface (Z-axis direction). At this time, since the portion where the Rayleigh scattered light intensity is measured most strongly is the place where the spot intensity is the highest, the sample side Z fine movement mechanism 30 is located at the place where the spot intensity becomes high according to the intensity measurement result displayed on the monitor of the computer 51. Positioning.

  Here, the distance between the probe 2 and the sample 28 is fed back by the probe-side Z fine movement mechanism 13, so that even when the sample-side Z fine movement mechanism 30 is operated, the distance between the two remains constant. The probe side Z fine movement mechanism 13 can be operated by the amount of movement of the side Z fine movement mechanism 30 operated.

(7) Sample positioning by the sample-side XY fine-movement mechanism (1) to (6), the tip of the probe 2 can be aligned with the portion where the intensity is maximum in the XYZ-axis direction of the evanescent field spot. . In this state, while controlling the distance between the probe 2 and the sample 28 by the probe side Z fine movement mechanism 13, the XY fine movement mechanism 30 on the sample side is raster-scanned and applied to the Z fine movement mechanism 13 or applied to the Z fine movement mechanism. The shape image of the sample 28 is measured by mapping the output of the displacement sensor 17 thus obtained. The position where the Raman spectroscopic measurement is performed is recognized from the measurement image, and alignment is performed by the sample side XY fine movement mechanism 30 by the control device 18 so that the position comes to the tip of the probe 2.

Thereafter, the Raman scattered light at the measurement position is spectroscopically analyzed by the spectroscope 48 and detected by the liquid nitrogen cooled CCD 49, whereby the spectroscopic analysis of the target portion can be performed.
A series of these operations is also performed on the computer 51. It is also possible to measure the mapping of the Raman scattered light scattered by the sample by mapping the detection signal image of the target Raman signal while performing the raster scan.
As described above, the procedure of (1) to (7) makes it possible to measure a transmissive sample with a scattering near-field microscope.

  In this embodiment, displacement sensors are arranged in all the fine movement mechanisms 11, 12, 13, and 30. When a piezoelectric element is used, drift occurs due to creep, or position reproducibility deteriorates due to hysteresis. However, a displacement sensor is provided to adjust the voltage applied to the piezoelectric element according to the set displacement of the control device 18. By providing such a closed loop mechanism, drift due to creep and displacement due to hysteresis are suppressed. However, if a slight decrease in the scattered light rate due to the positional deviation from the portion where the intensity of the evanescent spot is the highest is allowed, each fine movement mechanism can be used even without a displacement sensor. Cost can be reduced.

Another embodiment of the present invention is shown in FIG. FIG. 6 is a schematic view showing the operating principle of a reflection-type scattering near-field microscope for measuring a non-transparent sample. Note that components having the same functions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In this example, the strain on the semiconductor surface is detected by Raman scattered light.
The evanescent field generating optical system 70 includes an objective lens 71, an illumination system including a half mirror 72 and an illumination 73, an observation apparatus including an imaging lens 74, a half mirror 75, and a CCD camera 76, and a laser light source 77. A laser optical system including an optical fiber 78 and a collimator lens 79 is used.

  The objective lens 71 is disposed obliquely above the tip of the probe 2 and irradiates the surface of the sample 28 after the laser light emitted from the laser light source 77 is squeezed by the objective lens 71. At this time, the optical axis of the objective lens 71 is perpendicular so that the P-polarized component in the direction perpendicular to the sample 28 is incident, and the polarized light in the plane of the paper (XZ plane) in FIG. 6 is incident. These evanescent field generating optical systems 70 are mounted on an XY stage and a focusing stage (both not shown), and optical axis alignment and focusing with respect to the probe 2 are performed.

  The probe 2 was a cantilever 1 with a silver coat as in Example 1. The displacement of the cantilever is measured by an optical lever type displacement sensor 5, and the distance between the sample 28 and the tip of the probe 2 is controlled by the probe side triaxial fine movement mechanism 14. The probe side triaxial fine movement mechanism 14 is fixed to a Z coarse movement mechanism 23 driven by a stepping motor via an XY stage 19.

  Detection of scattered light scattered at the tip of the probe 2 is performed by a condensing objective lens 80 disposed above the probe 2. The scattered light collected by the condenser objective lens 80 is bent by the total reflection mirror 82, the Rayleigh scattered light component is removed by the notch filter 46, and the image is formed on the slit of the spectroscope 48 by the imaging lens 47. After entering the spectroscope 48, the spectral spectrum is measured by the liquid nitrogen cooled CCD camera 49, or the intensity is measured by the avalanche photodiode 52. The condensing optical system 81 is also placed on an XY stage and a focusing stage (not shown), and positioning with respect to the probe 2 is performed.

A sample side triaxial fine movement mechanism 30 is also provided on the sample side.
Next, the measuring method of the scattering near-field microscope of the present embodiment will be described with reference to FIG. The measurement flowchart is the same as that of the first embodiment shown in FIG. In the case of the same operation as in the first embodiment, detailed description is omitted.

(1) Spot and probe confirmation The laser beam from the laser 77 is incident on the optical system 70 for generating the evanescent field, and a spot is formed on the sample 28. Confirm. At this time, as in FIG. 5 of the first embodiment, a reflector (not shown) is placed perpendicular to the optical axis on the optical axis conjugate with the optical axis of the optical system 70 for generating the evanescent field with respect to the probe tip 2. By providing, the probe 2 and the spot can be easily observed. The amount of laser light is adjusted with an ND filter or the like so that the spot can be easily observed.

(2) Spot and probe alignment While observing the observation image of the evanescent field generating optical system 70, the XY stage 19 and the probe-side XY fine movement mechanism are operated to roughly align the probe 2 on the spot. The image of the evanescent field generating optical system 70 is an observation image from an oblique direction, and is disposed at an angle such that the cantilever does not become a shadow. Therefore, the probe tip 2 and the spot 42 can be easily identified.

(3) Confirmation of scattered light at the probe tip The probe 2 is approached to the sample 28, and while the distance between the probe 2 and the sample 28 is controlled by the Z fine movement mechanism 14, an offset voltage is applied to the XY fine movement mechanism 14 and the probe is applied. 2 is moved, and the probe is positioned at a place where the Rayleigh scattered light at the probe tip 2 is the strongest while observing the observation image of the optical system 70 for generating the evanescent field.
At this time, in addition to the evanescent field generating optical system 70, observation may be performed with another scattered light confirmation optical system 59 similar to that shown in FIG.

(4) Imaging measurement of evanescent spot The objective lens 80 is focused on the tip of the probe 2 using the XY stage 19 and the focusing stage of the condensing optical system 81. In this state, the probe side triaxial fine movement mechanism 14 controls the distance between the probe 2 and the sample 28 while performing raster scan in the XY plane, and the Rayleigh scattered light intensity is obtained by the avalanche photodiode 52 attached to the spectroscope 48. Detect and measure the intensity mapping of the spot 42. At this time, the notch filter 46 is removed from the optical path.

(5) Positioning of the probe by the probe-side XY fine movement mechanism The probe tip is positioned by the XY fine movement mechanism 14 at the place where the intensity is maximum in the spot from the obtained intensity mapping image of the spot. These operations are performed from a computer (not shown).

(6) Adjustment of focusing With the probe 2 approaching the spot of the evanescent field of the sample 28, an offset voltage is applied to the Z fine movement mechanism 30 on the sample side while measuring the Rayleigh scattered light intensity at the probe tip 2. Then, it is moved in a direction perpendicular to the sample surface (Z-axis direction). Based on the intensity measurement result displayed on the monitor (not shown) of the computer 51, the sample side Z fine movement mechanism 30 is positioned at a place where the spot intensity is high.
Here, since the distance between the probe and the sample is fed back by the probe side Z fine movement mechanism 14, even when the sample side Z fine movement mechanism 30 is operated, the distance between the two is kept constant. The probe side Z fine movement mechanism 14 can be operated by the amount of movement of the fine movement mechanism 30 operated.

(7) By positioning the sample by the sample-side XY fine movement mechanism (1) to (6), the probe tip can be aligned with the portion where the intensity is maximum in the XYZ-axis direction of the spot of the evanescent field.
In this state, the probe-side Z fine movement mechanism 14 controls the distance between the probe 2 and the sample 28, raster scans the XY fine movement mechanism 30 on the sample side, and applies the applied voltage to the Z fine movement mechanism 13 or the Z-axis fine movement mechanism. The shape image of the sample 28 is measured by mapping the output of the attached displacement sensor (not shown).
The position for Raman spectroscopic measurement is recognized from the measurement image, and alignment is performed by the sample-side XY fine movement mechanism 30 so that the position comes to the tip of the probe 2.
Thereafter, the Raman scattered light at the measurement position is spectroscopically analyzed by the spectroscope 48 and detected by the liquid nitrogen cooled CCD 49, whereby the spectroscopic analysis of the target portion can be performed. A series of these operations are performed on a computer.

In addition, by measuring the intensity of the Raman scattered light with the avalanche photodiode 52 while performing the raster scan with the sample side XY fine movement mechanism, it is possible to perform the imaging measurement of the Raman scattered light. From the obtained data, the distortion of the semiconductor sample can be measured. You can know the state.
With the measurement methods (1) to (7) described above, even a non-transparent sample can be reliably and easily measured by a scattering near-field microscope.

The present invention is not limited to the first and second embodiments.
For example, the scattered light measured in the procedure (4) of Example 1 and Example 2 is not limited to Rayleigh scattered light. For example, when a silicon probe is used, Raman scattered light is generated from silicon. It is also possible to measure the intensity distribution of the spot with this Raman scattered light. In the intensity distribution of the spot obtained when measuring Raman scattered light, the measured intensity increases as the intensity of the evanescent field increases. Furthermore, a probe with a carbon nanotube attached to the tip of a cantilever can be used for the purpose of high-resolution measurement of a shape image. In this case, the intensity distribution of the spot can be obtained by Raman scattered light of the carbon nanotube.

Moreover, although the imaging image displayed on the monitor connected to the computer was used as the scattered light display device, the display device may be an oscilloscope or the like.
In the procedure (6) of the first embodiment and the second embodiment, the probe side Z fine movement mechanisms 13 and 14 are used for the distance feedback between the probe 2 and the sample 28. However, the sample side Z fine movement mechanism 30 performs the feedback. Is also possible. In this case, the probe side Z fine movement mechanism 13 is moved in the Z-axis direction to adjust the focusing direction. Furthermore, in step (6), instead of operating the sample side Z fine adjustment mechanism 30 and the probe side Z fine adjustment mechanism 13, 14, the Z fine adjustment mechanism is attached to the objective lenses 38, 71, and the objective lenses 38, 71 themselves are operated. May be.

  In the first embodiment, a part of the procedures (1) to (7) may be omitted. For example, even in the procedure between (1) to (3), it is possible to roughly position to the evanescent spot, and the steps (4) to (6) are omitted and the procedure (7) is performed to scatter. Measurement with a mold near-field microscope is possible. It is also possible to omit (3) and perform alignment only with the intensity imaging image of the evanescent spot.

Further, the focusing adjustment in (6) may be omitted. In this case, the Z fine movement mechanism may be on either the sample side or the probe side.
The distance control method between the probe and the sample is not limited to the method using atomic force. For example, the cantilever is vibrated near the resonance frequency and brought close to the sample, and distance feedback is performed by changing the amplitude and phase at that time. It is also possible to perform.

  Further, the shape and material of the probe are not limited to the above-described embodiments, and for example, a straight type probe can be used. In the case of the straight type, when the probe is vibrated in a plane parallel to the sample surface and close to the sample surface, the distance between the probe and the sample is controlled by changes in amplitude and phase due to shear force acting on the probe tip. Alternatively, it is possible to apply a voltage between the sample and the probe and perform feedback by a tunnel current flowing between the sample and the probe. Further, it may be merely scattered at the tip by silicon, silicon nitride, or a metallic probe. Furthermore, a probe with a fluorescent label attached to the probe tip can also be used.

  Furthermore, the present invention can be applied to a sample that generates an evanescent field on the sample surface, such as a semiconductor laser or an optical waveguide. In the case of these samples, the sample surface can be scanned with a probe, the measurement location can be positioned from the intensity mapping image of the evanescent field, and the optical characteristics at that location can be measured. It is also possible to use a nonlinear optical system for the excitation light.

1 is a schematic view of a scattering near-field microscope according to a first embodiment of the present invention. FIG. 3 is a simulation result of intensity distribution of an evanescent field spot in the optical system of FIG. (a) P-polarized component in the XY plane (b) S-polarized component in the XY plane The flowchart which shows the illumination method of the scattering type near field microscope which concerns on the 1st Example and 2nd Example of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The general-view figure which shows the illumination method for cantilever observation of the scattering type near field microscope which concerns on 1st Example of this invention. 1 is a schematic view of an optical system for confirming scattered light of a scattering near-field microscope according to a first embodiment of the present invention. FIG. 6 is a schematic view of a reflective scattering near-field microscope according to a second embodiment of the present invention. FIG. 3 is an overview diagram showing a device configuration of a conventional scattering near-field microscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cantilever 2 Probe 4 Cantilever holder 5 Displacement sensor 6 Semiconductor laser 7 Condensing lens 8 Mirror 9 Mirror 10 Photo detector 11 X fine movement mechanism 12 Y fine movement mechanism 13 Z fine movement mechanism 14 (Probe side) Three-axis fine movement mechanisms 15, 16, 17 Displacement Sensor 18 Controller 19 XY stage 20 Measuring head 21 Stepping motor 22 Feed screw 23 Coarse movement mechanism 24 Micrometer 25 Micrometer 26 Base 28 Sample 29 Sample holder 30 (Sample side) 3-axis fine movement mechanism 31 Evanescent field generation mechanism 32 Laser light source 33 λ / 2 wavelength plate 34 Beam expander 35 Lens 36 Mask 37 Non-polarizing beam splitter 38 Oil immersion objective lens 41 Oil immersion oil 44 Total reflection mirror 45 Total reflection mirror 46 Notch filter 47 Imaging lens 4 Spectrometer 49 liquid nitrogen cooled CCD
50 control device 51 computer 52 avalanche photodiode (APD)
53 CCD camera 54 Monitor 58 Illumination 59 Scattered light confirmation optical system 60 Objective lens 61 Reflector 62 Illumination device 63 Half mirror 64 Imaging lens 65 CCD camera 66 Monitor 70 Evanescent field generation optical system 71 Objective lens 72 Half mirror 73 Illumination 74 Imaging lens 75 Half mirror 76 CCD camera 77 Laser light source 78 Optical fiber 79 Collimator lens 80 Condensing objective lens 81 Condensing optical system 101 Cantilever 102 Probe 104 Sample 105 Oil immersion oil 106 Oil immersion objective lens 108 Laser light source 110 Beam Expander 111 Mask 112 Half mirror 113 Lens 114 Lens 115 Z fine adjustment mechanism 116 Notch filter 117 Imaging lens 118 Spectrometer 119 Slit 120 Liquid nitrogen cooled CCD
121 XY fine movement mechanism 122 Avalanche photodiode (APD)
123 Computer 124 Controller 125 Controller 126 Photon Counter 127 Digital / Analog Converter 128 Amplifier 130 Half Mirror 131 Imaging Lens 132 CCD Camera 133 Monitor

Claims (9)

Evanescent field generating means for generating an evanescent field on the sample surface; and a probe for scattering the evanescent field in proximity to or in contact with the sample surface;
An XY fine movement mechanism for moving the probe and the sample relatively in the sample plane;
A Z fine movement mechanism for controlling the distance between the probe and the sample;
Scattered light condensing means for condensing the scattered light scattered by the probe;
A photodetector for measuring the intensity of the scattered light;
In a method for measuring the optical properties of a sample with a scattering near-field microscope, comprising a control device for driving the XY fine movement mechanism and the Z fine movement mechanism,
The XY fine movement mechanism is provided on both the probe side and the sample side, and the Z fine movement mechanism is provided on at least one of the probe side and the sample side,
Performing a raster scan in a region including an evanescent field generated on the sample surface by the XY fine movement mechanism on the probe side while keeping a constant distance between the probe and the sample surface by the Z fine movement mechanism; ,
A step of positioning the probe by the probe-side XY fine movement mechanism at a portion where the intensity of the evanescent field is maximized based on the intensity measurement result of the scattered light detected at that time ;
Raster scanning the sample surface with the sample side XY fine movement mechanism;
The probe tip is positioned by the sample side XY fine movement mechanism at an arbitrary position specified based on the shape image data acquired by the raster scan by the sample side XY fine movement mechanism, and the scattered light scattered by the probe at the specified position Collecting and detecting; and
A method for measuring optical properties of a sample using a scattering near-field microscope. Evanescent field generating means for generating an evanescent field on the sample surface; and a probe for scattering the evanescent field in proximity to or in contact with the sample surface;
An XY fine movement mechanism for moving the probe and the sample relatively in the sample plane;
A Z fine movement mechanism for controlling the distance between the probe and the sample;
Scattered light condensing means for condensing the scattered light scattered by the probe;
A photodetector for measuring the intensity of the scattered light;
In a method for measuring the optical properties of a sample with a scattering near-field microscope, comprising a control device for driving the XY fine movement mechanism and the Z fine movement mechanism,
The XY fine movement mechanism is provided on both the probe side and the sample side, and the Z fine movement mechanism is provided on at least one of the probe side and the sample side,
Performing a raster scan in a region including an evanescent field generated on the sample surface by the XY fine movement mechanism on the probe side while keeping a constant distance between the probe and the sample surface by the Z fine movement mechanism; ,
A step of positioning the probe by the probe-side XY fine movement mechanism at a portion where the intensity of the evanescent field is maximized based on the intensity measurement result of the scattered light detected at that time;
Raster scanning the sample surface with the sample side XY fine movement mechanism;
A step of acquiring optical image data by collecting and detecting scattered light scattered by the probe in a scanning plane together with a raster scan by the sample-side XY fine movement mechanism;
A method for measuring optical properties of a sample using a scattering near-field microscope. Evanescent field generating means for generating an evanescent field on the sample surface; and a probe for scattering the evanescent field in proximity to or in contact with the sample surface;
An XY fine movement mechanism for moving the probe and the sample relatively in the sample plane;
A Z fine movement mechanism for controlling the distance between the probe and the sample;
Scattered light condensing means for condensing the scattered light scattered by the probe;
A photodetector for measuring the intensity of the scattered light;
In a method for measuring the optical properties of a sample with a scattering near-field microscope, comprising a control device for driving the XY fine movement mechanism and the Z fine movement mechanism,
The XY fine movement mechanism is provided on at least one of the probe side and the sample side, and the Z fine movement mechanism is provided on both the probe side and the sample side,
The evanescent field generating means comprises an optical system comprising a lens having a focusing mechanism, and focusing on the sample surface;
Positioning the probe with the XY fine movement mechanism at a portion where the intensity of the evanescent field in the XY plane is maximized;
While controlling the distance between the probe and the sample by one of the Z fine movement mechanisms, the other Z fine movement mechanism is operated in the Z-axis direction to collect scattered light scattered by the probe. Determining the maximum intensity portion of the intensity distribution of the evanescent field on the Z-axis obtained by detection;
Determining the position of the probe and the sample using the two Z fine movement mechanisms at the maximum part of the evanescent intensity on the Z axis;
Collecting and detecting scattered light scattered by the probe;
A method for measuring optical properties of a sample using a scattering near-field microscope. The evanescent field generating means includes an optical system including a lens having a focusing Z coarse movement mechanism and a Z fine movement mechanism, and focusing on the sample surface by the Z coarse movement mechanism;
Positioning the probe with the probe-side XY fine movement mechanism at a portion where the intensity of the evanescent field in the XY plane is maximized ;
The Z fine movement mechanism for the focusing is operated in the Z-axis direction, the a focusing strength of the evanescent intensity distribution on the Z-axis obtained by detecting condenses the scattered light scattered by the probe into the portion having the maximum Positioning the lens by a Z fine movement mechanism ;
The method for measuring the optical properties of a sample using a scattering near-field microscope according to claim 1 , further comprising : The XY fine movement mechanism or the Z fine movement mechanism provided on the probe side of the scattering near-field microscope, the XY fine movement mechanism or the Z fine movement mechanism provided on the sample side, and a focusing Z provided on the objective lens among the fine movement mechanism, method of measuring samples of the optical characteristics caused by scattering near-field microscope according to any one of claims 1 to 4 having one or more of the fine movement mechanism displacement detection mechanism. Evanescent field generating means for generating an evanescent field on the sample surface;
A probe that scatters the evanescent field in proximity to or in contact with the sample surface;
An XY fine movement mechanism for moving the probe and the sample relatively in the sample plane;
In a method for measuring optical properties of a sample by a scattering near-field microscope equipped with
The XY fine movement mechanism is provided on at least one of the probe side and the sample side,
An objective for observing the probe tip so that the optical axis is in the range of 0 to θ degrees with respect to the angle θ formed by the line connecting the probe tip and the edge of the side surface of the cantilever and the sample surface as the reference surface. Placing a lens and irradiating the probe tip from the objective lens side with illumination light; and
Observing the probe tip and scattered light at the probe tip with a reflector arranged on an optical axis conjugate with the optical axis of the objective lens with respect to the probe tip;
Positioning the probe by any one of the XY fine movement mechanisms in a spot of an evanescent field based on the intensity observation measurement result of the scattered light;
Identifying a portion having the maximum evanescent intensity from within the spot and positioning the probe by any one of the XY fine movement mechanisms;
A method for measuring optical properties of a sample using a scattering near-field microscope. Evanescent field generating means for generating an evanescent field on the sample surface;
A probe that scatters the evanescent field in proximity to or in contact with the sample surface;
An XY fine movement mechanism for moving the probe and the sample relatively in the sample plane;
In a method for measuring optical properties of a sample by a scattering near-field microscope equipped with
The XY fine movement mechanism is provided on both the probe side and the sample side,
An objective lens is provided on the side facing the probe with respect to the sample, illumination light is irradiated obliquely above the cantilever with respect to the optical axis of the objective lens, and the tip of the probe reflected in the observation image by the objective lens Observing the evanescent field spot and the scattered light from the probe so that the image does not overlap the cantilever image;
Positioning the probe by the probe-side XY fine movement mechanism in the spot of the evanescent field based on the intensity observation measurement result of the scattered light;
Identifying the portion of the spot where the evanescent intensity is maximum and positioning the probe by the probe-side XY fine movement mechanism;
A method for measuring optical properties of a sample using a scattering near-field microscope. A step of maintaining a constant distance between the probe and the sample surface by a Z fine movement mechanism provided for controlling the distance between the probe and the sample during observation of scattered light at the probe tip ;
The method for measuring the optical properties of a sample with a scattering near-field microscope according to claim 6 . A scattering near-field microscope configured to perform at least one measurement method according to claim 1 .