JP2003108228A - Positioning apparatus, near-field microscope using the apparatus and near-field spectroscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positioning apparatus with a simple configuration capable of correcting accurately influences of drifts. SOLUTION: A positioning apparatus comprising a piezo-stage 18 mounting a test sample 24 and moving in the specified axis direction and a stage controller 20 making the piezo-stage 18 move in the specified axis direction, characterized in that the apparatus has a creep characteristic storage part 60 stored creep characteristics pre-measured and pre-formulated creeps of the piezo-stage 18 caused by a lapse of time in the driving axis direction, the stage controller 20 adds electric signals complementary with the creep characteristics stored into the storage part 60 to the piezo-stage 18 by matching with time information on the creep characteristics to drive the piezo-stage 18 in the driving axis direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device, a near-field microscope and a near-field spectroscopic device using the positioning device, and more particularly to an improvement of a drift reducing method.

[0002]

2. Description of the Related Art In recent years, a scanning near-field optical microscope has been developed based on a principle different from that of a general optical microscope or an electron microscope. Can be, and its application is expected.

This scanning near-field optical microscope is for detecting so-called near-field waves. For example, a small sample is placed on a flat substrate, and the sample is supposed to undergo total reflection from the back surface of the substrate. When light is incident at various angles, all propagating light is reflected, but surface waves called near-field waves are generated near the surface of the substrate and the sample. This surface wave is localized in a region around the sample surface within a distance within the wavelength of light.

Therefore, by inserting a sharp probe into the field of the near field wave to scatter the near field wave and measuring the intensity of the scattered light, the distance between the probe tip and the sample surface can be defined. . Therefore, by scanning the probe while keeping the intensity of the scattered light constant, the probe tip position accurately reflects the unevenness of the sample surface. Moreover, since the tip of the probe only exists in the field of near-field waves and does not contact the sample itself, it is possible to observe something that is non-contact, non-destructive to the sample and smaller than the wavelength of light. Is.

By the way, probe microscopes represented by atomic force microscopes, scanning tunneling microscopes, and near-field microscopes, in addition to the near-field microscopes described above, use a piezo stage for nanoscale micropositioning. There are many.

[0006]

However, although the piezo stage is capable of nano positioning, it has a problem in absolute accuracy and reproducibility such as creep and hysteresis. For example, even though the stage controller gives an instruction to stop driving the piezo stage, the piezo stage does not stand still at that position, but due to the passage of time, it will move in the direction of its drive axis Creep occurs.

Regarding the creep characteristic, in particular, it is dealt with by a method of directly measuring and correcting the driving amount of the stage by another means, a method of measuring a reference sample and converting the measurement result based on the result. Often. However,
The former requires additional hardware for position measurement, and thus has drawbacks such as a complicated device and a limited installation environment. The latter cannot be said to be a correction in a strict sense because it is based on the measurement that is deviated from the actual measurement in terms of time or space.

This problem has been more serious in a near-field measuring apparatus since the probe or the stage is driven within a very small range of the wavelength of light or less. The present invention has been made in view of the above problems of the prior art, and an object thereof is a positioning device capable of accurately correcting the influence of drift with a simple configuration, and a near-field microscope and a near-field spectroscopic device using the positioning device. To provide.

[0009]

In order to achieve the above object, a positioning device according to the present invention comprises a piezo stage on which a sample is placed and which moves in a specific axial direction, and a piezo stage which moves the piezo stage in the specific axial direction. A positioning device including a stage controller to be moved, and a creep characteristic storage unit. Then, the stage controller applies an electric signal complementary to the creep characteristic of the creep characteristic storage unit to the piezo stage in accordance with time information of the creep characteristic, and drives the piezo stage in the drive axis direction. It is characterized by

Here, the creep characteristic storage unit stores the creep characteristic which has been previously measured and formulated as creep with time in the drive axis direction of the piezo stage. Further, in order to achieve the above object, a positioning device according to the present invention includes a piezo stage on which a sample is placed and which moves in a specific axial direction, and a stage controller which drives the piezo stage in the specific axial direction. The positioning device further includes a creep characteristic storage unit, a measuring unit, and a correcting unit.

Here, the creep characteristic storage section stores the creep characteristic which is measured and formulated beforehand with respect to the lapse of time in the drive axis direction of the piezo stage. Further, the measuring means obtains position information in the drive axis direction of the piezo stage together with time information from the measurement site of the sample placed on the piezo stage.

According to the creep characteristic of the creep characteristic storage unit, the correcting means adjusts the time information of the creep characteristic to the measurement result obtained by the measuring means in the drive axis direction of the piezo stage by software correction. The measurement result is obtained by removing the influence of the creep of the piezo stage.

In the present invention, it is preferable that the creep characteristic of the piezo stage can be expressed by the following equation 2.

## EQU00002 ## r.times. (1 + .gamma..times.Log (t / 0.1)) (2) where r is a constant .gamma. That can be calculated using the data obtained by the measuring means, and .gamma. The constant t that can be calculated using the data obtained is the time information

The time information t is, for example, an elapsed time based on the moment when the driving of the piezo stage is stopped by the stage controller, or the time when the driving of the piezo stage is stopped. It means the elapsed time, etc.

The creep characteristic expressed by the above equation 2 is
For example, the unit of the horizontal axis is time, and the vertical axis is Z-axis position information. On the other hand, although the unit of the vertical axis of the measurement result is the Z-axis position information, even if the unit of the horizontal axis is the X position information, for example, when the X position information is obtained, the time of the formula of the creep characteristic is obtained. By obtaining the time or time information that can be associated with the information t, for example, by converting the axis unit between the time axis and the position axis, it is possible to associate the formula of the creep characteristic with the measurement unit of the axis unit.

Further, in the present invention, the measuring means obtains an image for each surface, and after obtaining the image of the one surface, a plurality of points are appropriately selected from the image, and the constant in the formula of the creep characteristic is selected. A constant determining means for calculating the values of r and γ is provided. Then, the correction means, the value obtained by the constant determination means,
Corresponding constants r and γ in the formula of the creep characteristic storage unit
According to the creep characteristics substituted in, software correction is applied to the data of the entire image obtained by the measuring means,
It is preferable to obtain the measurement result in which the influence of the creep of the piezo stage is removed.

Further, in the present invention, the measuring means obtains an image for each row, and after obtaining the one row image, a plurality of points are appropriately selected from the image to obtain a constant in the formula of the creep characteristic. A constant determining means for calculating the values of r and γ is provided. According to the creep characteristic obtained by substituting the value obtained by the constant determining means into the corresponding constants r and γ in the formula of the creep characteristic storing section, the correcting means performs software for the data of the row obtained by the measuring means. A correction is applied to obtain a measurement result in which the influence of the creep of the piezo stage is removed, and the corrected measurement result is displayed. Then, it is preferable that the measurement by the measuring unit, the constant calculation by the constant determining unit, the software correction by the correcting unit, and the display of the measurement result after the correction are performed for each row.

Further, in order to achieve the above object, the near-field microscope according to the present invention comprises a scattered light collecting means for collecting scattered light generated by causing a probe to enter the field of the near-field light on the sample measurement surface, and a sample. In a near-field microscope equipped with a stage on which is mounted and an observing means for observing a sample image by the scattered light of the near-field light collected by the scattered-light collecting means, the positioning device according to the present invention is provided with the probe or stage. Is provided in the desired drive axis direction.

In order to achieve the above object, a near-field spectroscopic device according to the present invention includes a probe and a piezo stage on which a sample is placed, and the near-field spectroscopic device is provided in the Z-axis direction between the sample measurement surface and the tip of the probe. A stage controller that scans the tip position of the probe in the X and Y-axis directions on the sample measurement surface while keeping the separation distance constant, and simultaneously acquires the separation information and spectrum information at each measurement site on the sample measurement surface. In a possible near-field spectroscopic device, the positioning device according to the present invention is provided in a desired drive axis direction of the probe or the stage.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A schematic configuration of a measuring device using a positioning device according to an embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, an example will be described in which a near-field spectroscopic device is assumed as the measuring device, and the unevenness information of the sample measurement surface obtained by the device is software-corrected to correct the influence of the creep of the piezo stage. The near-field spectroscopic device 10 shown in the figure includes separation information acquisition means (measurement means) and spectrum information acquisition means.

The separation information acquisition means is, for example, an optical fiber probe 12, a near-field head 14, a Z-axis direction position control optical system 16, an XYZ piezo stage (positioning device) 18, and a stage controller (positioning device).
20 and a computer main body (positioning device) 22.

The XYZ piezo stage 18, the stage controller 20 and the like scan the sample 24 and the tip of the probe 12 in the Z-axis direction which separates or brings the tip of the probe 12 into the vicinity of the sample 24 and the probe 12 when obtaining the separation information and the spectrum information.
The tip is brought close to a predetermined distance in the near field region.

In this embodiment, the XYZ piezo stage 1
A sample 24 is placed on the surface 8, and the sharp probe 12 is inserted into the field of the near-field light 25 to scatter the near-field light 25. At this time, the probe 1 is moved by the near-field head 14.
2 is vibrating slightly at its resonance frequency. The Z-axis direction position control optical system 16 irradiates the tip of the probe 12 with the light 26, detects the modulated reflected light 28 from the tip of the probe 12, and detects the change in the vibration amplitude of the tip of the probe 12 from the light 28. To do. The probe 1 is driven by the XYZ piezo stage 18 driven by the stage controller 20 while keeping the vibration amplitude of the tip of the probe 12 constant.
2 scans are performed. This allows the XYZ piezo stage 18
From the above, the XY position information of each measurement point and the height information at each measurement point are obtained from the timer unit 21 at the same time as the measurement time in the separation information storage unit 32 of the hard disk (HDD) 30 of the computer main body 22. As a result, the tip of the probe 12 and the sample 2
4 The distance from the measurement surface can be specified.

The spectrum information acquisition means is, for example, an excitation laser 36, an optical fiber probe 12, and a spectroscope 3.
8, detector 40, XYZ piezo stage (positioning device) 18, stage controller (positioning device)
20 and a computer main body (positioning device) 22.

Then, the laser beam 4 from the excitation laser 36
2 is incident on the fiber probe 12, and the probe 12
The near-field light 25 exudes from the opening at the tip. The near-field light 25 is localized in a region narrower than the wavelength of light at the tip of the probe 12, and when the tip of the probe 12 and the sample measurement surface 24 are brought close to a region narrower than the wavelength of light by the stage controller 20, The light 25 exuding from the probe tip 12 is scattered or reflected by the sample measuring surface 24, and the scattered light or reflected light 44 is condensed from the opening at the tip of the probe 12 and dispersed by the spectroscope 38. The dispersed light is detected by the detector 40, and its light intensity is stored in the HDD 3 of the computer main body 22 together with the wavelength information obtained from the spectroscope 38.
0 of the spectrum information storage unit 42.

By configuring the near-field spectroscopic device 10 in this way, it is possible to simultaneously obtain height information and component information at each measurement site on the sample surface and display them on the display 45.

By the way, including the near-field spectroscope 10,
A probe microscope typified by an atomic force microscope, a scanning tunnel microscope, a near-field microscope, etc. often uses a piezo stage for nanoscale micropositioning. However, although the piezo stage is able to position the nano, for example, even though the stage controller has issued an instruction to stop the drive of the piezo stage, the piezo stage is not standing still at that position As a result, creep occurs in which the vehicle moves in the direction of the drive axis when it slips. Particularly, in the near-field measuring device, the probe or the stage is driven within a range narrower than the wavelength of light, so this problem is more serious.

Therefore, in the present invention, the creep characteristic is measured and formulated in advance in order to accurately correct the influence of the drift of the piezo stage with a simple structure. In the present embodiment, for example, as shown in FIG. 2A, one image is obtained from the same measurement surface each time a predetermined time t elapses from the moment when the driving of the piezo stage is stopped by the stage controller. For example, this is repeated 8 times. Then, the creep characteristic as shown in FIG. This is formulated as in the following Expression 3, and the separation information of the separation information storage unit 32, that is, the unevenness information of the sample measurement surface is corrected based on the theoretical curve.

## EQU00003 ## r.times. (1 + .gamma..times.Log (t / 0.1)) (3) where r is a constant .gamma. That can be calculated using the data obtained by the near field spectroscopy apparatus 10. The constant t that can be calculated using the data obtained by the device 10 is the elapsed time from the moment when the driving of the piezo stage is stopped by the stage controller.

To this end, the present embodiment is provided with a creep characteristic storage unit 60 for storing the formula for the creep characteristic of the above-mentioned equation 3, and a CPU 46 as a constant determining means and a software correcting means.

First, the separation information acquisition means obtains height information from each measurement site of the sample placed on the piezo stage, obtains one surface image, and stores it in the separation information storage section.

As a function of the constant determining means, the CPU 46 appropriately selects a plurality of points from the one surface image obtained as described above, and determines the constant r, in the formula of the creep characteristic.
Calculate the value of γ. For example, constant γ = 0.34, constant r =
To get 8.4. This is stored in the creep characteristic storage unit 60. Creep characteristics are measured in advance in the XYZ axis directions of the piezo stage and the formulated creep characteristics are stored.

As a function of the correction means, the CPU 46 sets the values of the constants r and γ in the creep characteristic formula stored in the creep characteristic storage unit 60 to the constant γ = 0.
34 and the constant r = 8.4 are substituted into the corresponding constants r and γ in the formula of the creep characteristic to obtain the creep characteristic in the Z-axis direction, for example. According to the obtained creep characteristics, software correction is applied to the entire image data in the separation information storage unit to obtain a measurement result in which the influence of the creep of the piezo stage is removed.

In the creep characteristics shown by the equation 3, for example, the unit of the horizontal axis is time, and the vertical axis is Z-axis position information. On the other hand, the unit of the horizontal axis of the vertical axis of the measurement result is, for example, the X position information, but in the present embodiment, as described above, the acquisition time of the X position information is determined by the time counting unit 21, for example. It is obtained together with the time information that can be associated with the formula time information t. Therefore, for example, by converting the unit of the axis between the time axis and the position axis, it is possible to associate the formula of the creep characteristic with the unit of the axis, for example, the X-axis position information of the separation information storage unit.

Then, in consideration of such association of the units of axes, for example, the data d in the separation information storage unit as shown in FIG. 3A is creeped as shown in FIG. By dividing by the theoretical curve tc of the characteristic, the same figure (C)
It is possible to obtain the data d ′ from which the influence of creep as shown in FIG.

As described above, in this embodiment, the creep characteristic of the piezo stage was successfully formulated, and the software effect was applied to the entire measurement result based on the theoretical curve to correct the influence of the creep. The result can be corrected accurately. Moreover, in this embodiment, since the software correction is performed using the theoretical curve, the configuration is simple.

Further, since the positioning device according to this embodiment is used in the near-field spectroscopic device, the probe 12 with high accuracy is used.
Since the piezo stage 18 can be driven, more accurate measurement results can be obtained.

In the above construction, an example in which one surface image is obtained by the measuring means has been described, but the present invention is not limited to this, and instead of this, the measuring means may be used for each line. Get the image. Then, after obtaining one line image by the constant determining means, a plurality of points are appropriately selected from the image and the values of the constants r and γ in the formula of the creep characteristic are calculated. Then, according to the creep characteristic obtained by substituting the value obtained by the constant determining means into the corresponding constants r and γ in the formula of the creep characteristic storing section by the correcting means, the data of the row obtained by the measuring means is calculated. Software correction is applied to obtain a measurement result in which the influence of the creep of the piezo stage is removed. The corrected measurement result is displayed on the display. Then, the measurement by the measuring unit, the constant calculation by the constant determining unit, the software correction by the correcting unit, and the display of the measurement result after the correction can be performed for each row. Thereby, in the present embodiment, the correction result can be sequentially displayed during the measurement, for example, every time the measurement of each row is completed.

Further, in the above-mentioned configuration, an example in which the positioning device according to the present embodiment is used as a stage of a near-field spectroscopic device has been described, but the present invention is not limited to this, and a piezo stage is used. It can be used in any device.

It is suitable for a stage of a probe microscope such as an atomic force microscope, a scanning tunnel microscope, a near field microscope, etc., which requires particularly precise positioning. For example, scattered light collecting means for collecting scattered light generated by entering the probe into the near-field light field of the sample measurement surface, a stage on which the sample is mounted, and the near-field collected by the scattered light collecting means. In a near-field microscope having an observation means for observing a sample image by scattered light of light, it can be used for driving a probe or a stage.

As described above, by using the positioning device according to the present invention in the near-field microscope, the probe or the stage can be driven with high accuracy as in the case of using the near-field spectroscopic device, so that the measurement with higher accuracy can be performed. The result is obtained.

Further, the example in which the positioning device according to the present invention is used for the piezo stage has been described, but the present invention can be applied to other drive mechanisms, for example, a fine feed mechanism for a probe using a piezo element.

In the above configuration, the creep characteristic in the Z-axis direction has been described for the sake of description, but the present invention can be applied to the creep characteristic in the drive axis direction, the X-axis direction and the Y-axis direction using other piezoelectric elements.

Further, in the above-mentioned configuration, an example in which the measurement result is software-corrected has been described, but instead of this, it can be applied to the correction of the drive control value for the piezo stage.

FIG. 4 shows a schematic structure of a near-field spectroscopic microscope using such a positioning device. In addition,
Reference numeral 100 is added to portions corresponding to those in FIG. 1 and description thereof is omitted.

That is, the near-field spectroscopic device 11 shown in FIG.
0 uses a positioning device that is characteristic in this embodiment, and includes a piezo stage 118, a stage controller 120, a creep characteristic storage unit 160, and a piezo control information storage unit 162.

The creep characteristic storage section 160 stores the creep characteristic of the piezo stage 181 obtained as described above.

The piezo stage control information storage unit 162
Stores an electric signal complementary to the creep characteristic stored in the creep characteristic storage unit 160 as an electric signal applied to drive the XYZ piezo stage 118 by the stage controller 120.

When a signal instructing the start of measurement is input, the stage controller 120 matches the electric signal complementary to the creep characteristic of the creep characteristic storage unit 160 with the time information of the creep characteristic. Applied to the piezo stage 118,
8 is driven in the drive axis direction.

As a result, the near-field spectroscopic device 11 shown in FIG.
0, like the near-field spectroscopic device shown in FIG. 1, succeeded in formulating the creep characteristic, and performed creep correction based on the theoretical curve. That is, in the present embodiment, since an electric signal complementary to the creep characteristic is applied to the piezo stage to drive the piezo stage, the influence of creep can be corrected and the piezo stage can be accurately positioned. Moreover, the near-field spectroscopic device 110 shown in the same figure, like the near-field spectroscopic device shown in FIG. 1, is software-corrected using the theoretical curve, and therefore has a simple configuration. Also,
It is also preferable to add the following mechanism to the near-field spectroscope according to the present embodiment, for example, the near-field spectroscope shown in FIG. 1 according to the purpose of use.

<Continuous Measurement> By the way, in an analyzer having a nano-level resolution typified by a probe microscope, as a practical problem, mechanical drift of the apparatus and drift of laser intensity are completely removed. It is not possible.

Therefore, in general, an image in which the drift is suppressed is measured by ensuring a scan speed faster than this drift amount. However, in near-field spectroscopy, the scanning speed cannot be increased because it takes time to measure the spectrum. For this reason, when measuring a wide range of data, the influence of drift has been strong.

Therefore, it is also preferable to use a near-field spectroscopic apparatus 210 for measuring the shape of the sample surface, the spectrum of the sample surface and the time-resolved data as shown in FIG. It should be noted that the reference numeral 200 is added to the portion corresponding to FIG. 1 and the description thereof is omitted. The near-field spectroscopic apparatus 210 shown in the figure includes an input device 252 and a measurement condition storage unit 264.

The input device 252 inputs a plurality of mapping measurement conditions to the computer main body 222 in advance. As this mapping measurement condition, for example, a measurement region, a feedback condition, a spectrum measurement condition, etc. are input. The measurement condition storage unit 264 stores mapping measurement conditions such as a measurement area input from the input device 252.

When a signal instructing the start of measurement is input to the computer main body 222, the CPU 246
By accessing the mapping measurement condition information of the measurement condition storage unit 264 and controlling the operation of each device of the near-field spectroscopic device 210 including the stage 218, the stage controller 220, etc., according to the mapping measurement condition information, To measure.

Here, in the conventional mapping measurement, FIG.
It was general to set one wide measurement range A as shown in (1) and perform mapping measurement for the wide measurement range A at a time.

However, in the present embodiment, for setting the measurement area, for example, as shown in FIG. 7, a wide measurement range A is set to a plurality of areas, for example, four areas A1, A2, A.
It is divided into 3 and A4, and each is measured separately.

Here, each measurement image is provided with a margin at a portion adjacent to another image, and it is preferable to combine each measurement result through the margin after measurement.

In this embodiment, when the image I1 obtained from the area A1 and the image I2 obtained from the area A2 are combined as shown in FIG. 8A, the image I1 obtained from the area A1 is combined. The margin t1 is provided, and the image I2 obtained from the area A2 is provided with the margin t2. Therefore, the image I1 obtained from the area A1 and the image I2 obtained from the area A2 can be combined via the margins t1 and t2.

By utilizing such a combination, finally,
By combining the image I1 obtained from the region A1, the image I2 obtained from the region A2, the image I3 obtained from the region A3, and the image I4 obtained from the region A4, one image I ′ is obtained. Therefore, the measurement result regarding the wide measurement area A can be obtained.

As described above, in the present embodiment, the wide measurement range is divided into a plurality of areas and the respective measurements are made separately. As a result, in the present embodiment, the measurement time for one measurement can be shortened, so that the influence of drift or the like can be suppressed to a low level. Therefore, the influence of drift on the entire measurement result can be significantly suppressed.

When combining the measurement images, the CPU
Thus, the two-dimensional correlation coefficient of the overlapping portion of each image is obtained. Here, it is also preferable from the viewpoint of easiness of operation and the like that the arrangement of each image whose coefficient is as close to 1 as possible is obtained and the automatic alignment of each image is performed.

<Independent Designation of Surface Shape and Spectrum Measurement Range> In the near-field spectroscopic microscope, surface shape and spectrum mapping measurements are performed simultaneously.

Here, generally, the same points were selected as the measurement points of the surface shape and the spectrum. However, since spectral mapping is usually very time-consuming, it was necessary to remeasure only the surface shape of the same region again when obtaining the surface shape in more detail.

In this method, since it is necessary to perform the measurement twice, the procedure is complicated, and it is not always true that the same region is measured due to stage drift or the like.

Therefore, it is also preferable to use a near-field spectroscope 310 for measuring the shape of the sample surface, the spectrum of the sample surface, and time-resolved data as shown in FIG. In addition,
Reference numeral 300 is added to the portion corresponding to FIG. 1 to omit the description.

The near-field spectroscopic apparatus 310 shown in the figure includes an input device 352 and a measurement point setting information storage section 366. The input device 352 sets a mapping measurement point for surface shape measurement and a mapping measurement point for spectrum separately. The measurement point information storage unit 366 stores a mapping measurement point for surface shape measurement and a mapping measurement point for spectrum, which are input from the input device 352.

When a signal instructing the start of measurement is input to the computer main body 322, the CPU 346
The measurement point setting information in the measurement point information storage unit 366 is accessed, and according to the measurement point setting information, for example, the stage 31
8. Control the operation of each device of the near-field spectroscopic device 310 including the stage controller 320.

For example, the position of the tip of the probe 312 is shown in FIG.
, Each mapping measurement point Pi indicated by the intersection of the gratings (for example, the measurement interval is equal to or less than the wavelength λ of light, for example,
In 2), the surface shape is measured, and the stage controller is instructed to control the XYZ stage so that the spectrum mapping measurement is performed on each spectrum mapping measurement point Qi indicated by a black circle on the grid. here,
In the present embodiment, it is preferable that the number of spectrum measurement points Qi is smaller than the number of surface shape measurement points Pi in order to shorten the measurement time.

As a result, the near-field spectroscopic device shown in the figure can perform the mapping measurement of the surface shape and the spectrum with the accuracy corresponding to the resolution of the surface shape and the resolution of the spectrum in one measurement. Moreover, since the number of spectrum measurement points Qi is smaller than the number of surface shape measurement points Pi, the measurement time can be significantly shortened.

Besides, instead of setting the measurement points Qi of the spectrum evenly on the measurement surface as shown in FIG.
For example, as shown in FIG. 10, it is also possible to set the measurement area A1 of the spectrum in a small area on the measurement surface and the measurement area A2 of the surface shape in the remaining wide area. This is preferable because the same effect as can be obtained.

[0071]

As described above, according to the positioning device of the present invention, the creep characteristic storage section that stores the formulated creep characteristic by measuring the creep in the drive axis direction of the piezo stage and the creep characteristic storing section A stage controller for applying an electric signal complementary to the characteristics to drive the piezo stage is provided. As a result, in the present invention, the driving of the piezo stage is controlled based on the theoretical curve of the creep characteristic, so that the influence of drift can be accurately corrected with a simple configuration. Further, according to the positioning device of the present invention, the creep characteristic storage unit that measures the creep in the drive axis direction of the piezo stage and stores the formulated creep characteristic, and the creep characteristic storage unit from the measurement site of the sample on the piezo stage Measuring means for obtaining position information in the drive axis direction of the piezo stage, and with respect to the drive axis direction of the piezo stage, according to the creep characteristic of the creep characteristic storage section,
It is decided to provide a correction means for performing software correction on the measurement result obtained by the measurement means to obtain the measurement result in which the influence of creep is removed. As a result, in the present invention, since the entire measurement result is corrected based on the theoretical curve, the influence of drift can be corrected accurately with a simple configuration.
Further, in the present invention, there is provided constant determining means for obtaining an image for each measurement site by the measuring means, and then appropriately selecting a plurality of points on the image to calculate a constant in the formula of the creep characteristic. Then, according to the creep characteristic obtained by substituting the value obtained by the constant determining means into the corresponding constant in the formula of the creep characteristic by the correcting means, software correction is applied to the data of the measurement site obtained by the measuring means. By obtaining the measurement result from which the influence of creep has been removed and displaying the corrected measurement result for each measurement site, the correction result can be displayed sequentially during measurement, for example, after each measurement site measurement is completed. . Further, by using the positioning device according to the present invention in a near-field microscope or a near-field spectroscopic device, it is possible to drive the probe or stage with high accuracy, so that a more accurate measurement result can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of a near-field spectroscopic device using a positioning device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a measurement example of creep characteristics of the piezo stage shown in FIG.

FIG. 3 is an explanatory diagram of a software correction method based on a formula of creep characteristics of measurement results obtained by the near-field spectroscopic device shown in FIG. 1.

4 is a modified example of the creep correction mechanism in the near-field spectroscopic device shown in FIG.

5 is an explanatory diagram of a continuous measurement mechanism suitable for use in the near-field spectroscopic device shown in FIG.

FIG. 6 is an example of setting a general measurement area.

7 is an example of setting a measurement region suitable for use in the continuous measurement mechanism shown in FIG.

8 is an explanatory diagram of a method of combining divided images obtained by the continuous measurement mechanism shown in FIG.

9 is an explanatory diagram of a measurement range independent designating mechanism suitable for use in the near-field spectroscopic device shown in FIG. 1. FIG.

FIG. 10

11 is an example of measurement range independent designation by the measurement range independent designation mechanism shown in FIG.

[Explanation of symbols]

10 Near-field spectroscopic device (measuring means) 18 Piezo stage (positioning device) 20 Stage controller (positioning device) 46 CPU (correction means, constant determination means) 60 Creep characteristics storage section

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) // H01J 37/20 G12B 1/00 601G (72) Inventor Fuminori Sato 5 Japan spectroscopy at 2967 Ishikawa-cho, Hachioji-shi, Tokyo In-house F-term (reference) 2F065 AA02 AA03 AA06 AA24 AA49 AA50 DD06 EE07 FF04 GG04 LL02 MM03 PP12 QQ24 QQ31 QQ32 QQ36 SS01 2F078 CA08 CB14 CC07 5C001 AA03 AA04 CC04 5H303 AA20 CC06 DD14

Claims (7)

[Claims] 1. A positioning device comprising a piezo stage on which a sample is placed and which moves in a specific axial direction, and a stage controller which moves the piezo stage in the specific axial direction, wherein the piezo stage is driven in advance. A creep characteristic storage unit that stores the creep characteristic that has been formulated by measuring the creep due to the passage of time in the axial direction is provided, and the stage controller, an electric signal complementary to the creep characteristic of the creep characteristic storage unit, A positioning device characterized by applying to the piezo stage in accordance with time information of the creep characteristic to drive the piezo stage in the drive axis direction. 2. A positioning device comprising a piezo stage on which a sample is placed and which moves in a specific axial direction, and a stage controller which drives the piezo stage in the specific axial direction, in which the piezo stage is driven in advance. From the measurement site of the sample placed on the piezo stage, a creep property storage unit that stores the creep property that has been formulated by measuring the creep over time in the axial direction,
Measuring means for obtaining position information in the drive axis direction of the piezo stage together with time information, and with respect to the drive axis direction of the piezo stage, according to the creep characteristics of the creep characteristic storage unit, to the measurement result obtained by the measuring means, A positioning device comprising: a correction unit that performs software correction in accordance with time information of the creep characteristic to obtain a measurement result in which the influence of the creep of the piezo stage is removed. 3. The positioning device according to claim 1, wherein the creep characteristic of the piezo stage can be expressed by the following mathematical formula 1. ## EQU1 ## r × (1 + γ × Log (t / 0.1)) (1) where r is a constant γ that can be calculated using the data obtained by the measuring means, and the constant γ obtained by the measuring means. The constant t that can be calculated using the data obtained is the time information 4. The positioning device according to claim 2, wherein the measuring means obtains an image for each surface, and after obtaining the one surface image, a plurality of points are appropriately selected from the image. , Constant determining means for calculating the values of constants r and γ in the creep characteristic formula, wherein the correcting means uses the value obtained by the constant determining means as the corresponding constant r in the formula of the creep characteristic storing unit. , Γ according to the creep characteristics substituted in the measuring means, software correction is applied to the data of the entire image obtained by the measuring means, and a measurement result in which the influence of the creep of the piezo stage is removed is obtained. . 5. The positioning device according to claim 2, wherein the measuring unit obtains an image for each line, and after obtaining the one line image, a plurality of points are appropriately selected from the image, A constant determining means for calculating the values of constants r and γ in the creep characteristic formula is provided, and the correction means uses the value obtained by the constant determining means as the corresponding constant r, in the formula of the creep characteristic storage unit. According to the creep characteristics substituted for γ, software correction is applied to the row data obtained by the measuring means, the measurement result in which the influence of the creep of the piezo stage is removed is obtained, and the corrected measurement result is displayed. The positioning device is characterized in that the measurement by the measuring unit, the constant calculation by the constant determining unit, the software correction by the correcting unit, and the display of the corrected measurement result are performed for each row. 6. A scattered light collecting means for collecting scattered light generated by advancing a probe into a field of near-field light on a sample measuring surface, a stage on which a sample is placed, and scattered light collecting means for collecting the scattered light. In a near-field microscope equipped with an observation means for observing a sample image by scattered light of near-field light, the positioning device according to any one of claims 1 to 5 is provided in a desired drive axis direction of the probe or stage. A near-field microscope characterized by being provided. 7. A probe and a piezo stage on which a sample is placed are provided, and the tip position of the probe is measured while maintaining a constant Z-axis separation distance between the sample measurement surface and the probe tip. A near-field spectroscopic device comprising: a stage controller that scans in the X and Y axis directions on a surface, and is capable of simultaneously acquiring separation information and spectrum information at each measurement site of a sample measurement surface. A near-field spectroscopic device comprising the positioning device according to claim 1 provided in a desired drive axis direction of the probe or stage.