JPH06201370A - Scanning probe microscope - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Providing an optical lever method as a probe displacement detection method for a probe scanning microscope in which the probe is attached to an actuator and moved, providing high resolution and a wide measurement area. Realize a scanning probe microscope. [Configuration] A cantilever-shaped probe is brought close to the sample up to a minute distance, and minute forces such as atomic force acting between the two are detected as the displacement of the probe, and the probe is scanned over the sample surface. The probe scanning microscope is designed to measure the shape of the sample and the physical properties of the surface, and in addition to the optical system that detects the displacement of the probe, the position of the mounting part of the probe by scanning the probe. Of the probe displacement signal caused by the change of the angle and the angle, the optical system that irradiates the probe mounting part with laser light to detect it, and the position or angle of the mounting part of the probe detected by this detection optical system or its And a means for correcting the probe displacement signal detected by the probe displacement detection optical system according to changes in both.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an atom acting between a probe and a sample, such as an atomic force microscope (hereinafter simply referred to as AFM), in which a cantilever-shaped probe is brought close to a sample to a minute distance. A probe scanning microscope that detects micro force such as inter-force as displacement of the probe and scans the probe over the sample surface to measure the shape and physical properties of the sample. , To improve its measurement accuracy and measurement performance.

[0002]

2. Description of the Related Art When measuring using an AFM, an optical lever method shown in FIG. 10 is generally used as a method for detecting the displacement of a cantilever-shaped probe. In this optical lever method, the laser light emitted from the laser light source is applied to the mirror surface on the back surface of the probe that is arranged close to the sample up to a minute distance,
The split light reflected from the back of the probe is divided into two parts.
This is to detect the displacement of the probe and to detect the force acting between the probe and the sample by detecting the difference between the amounts of light received by the two elements and the light received by the two elements.

However, in this optical lever system, the relative position between the probe and the optical lever cannot be changed, so that
The probe cannot be scanned, and the sample is attached to a fine movement mechanism such as a piezoelectric actuator and scanned. Therefore, there is a limit to the size of the sample that can be handled, and it is necessary to cut the sample into a predetermined size even if a semiconductor-related sample that has a particularly high need is not handled as it is in the wafer size.

Further, in order to cope with the wafer size, a system has been developed in which the displacement detection system of the probe is downsized, the probe and the displacement detection system are attached to the actuator, and both are moved together. This utilizes the self-coupling effect in which the oscillation state of the laser diode is changed by the return light to the laser diode reflected on the back surface of the probe by the scoop method (FIG. 11). The resolution is not as good as the method.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and is a method for detecting the displacement of a probe in a probe scanning microscope in which the probe is attached to an actuator and moved. The present invention aims to provide a probe scanning type microscope having a high resolution and a wide measurement area, which is capable of handling a large sample such as a wafer.

[0006]

The structure of the present invention for solving the above-mentioned problems is such that a cantilever-shaped probe is brought close to a sample up to a minute distance, and a minute force such as an atomic force acting between the two is used. A probe scanning microscope that detects force as displacement of the probe and scans the probe on the surface of the sample to measure the shape of the sample, the physical properties of the surface, and the like. The probe is attached to an actuator and moved, and in the probe scanning microscope using an optical lever method as a system for detecting the displacement of the probe, in addition to the optical system for detecting the displacement of the probe, An optical system for irradiating the probe mounting portion with a laser beam to detect an error in the probe displacement signal due to a change in the position or angle of the mounting portion of the probe caused by scanning the needle, and this detection optical system. Before detected by The position or angle or the change in both the mounting portion of the probe, characterized in that a means for correcting the probe displacement signal detected by the probe displacement detection optical system. Further, a divided photodiode such as a two-divided photodiode is used as the detection element of both detection optical systems, and the difference signal of the light amount of each detection element is divided by the total light amount incident on this photodiode. Is characterized by. The laser beam of the probe displacement detection optical system or the laser beam of the probe displacement detection optical system and the probe are scanned based on the probe movement signal applied to the actuator to which the probe is attached. It is characterized by comprising a mechanism for moving the laser beam of the optical system for detecting the error of the probe displacement signal caused by the change of the angle and the position by applying the laser beam to the probe mounting portion. Further, as the laser beam moving mechanism, a mirror is arranged in a laser irradiation optical system, and the laser beam is moved by changing an angle of the mirror. Further, as the laser beam moving mechanism, a photoacoustic element is arranged in a laser irradiation optical system, and the diffraction angle of the laser beam is changed by the photoacoustic element to move the laser beam. . Further, as the laser light moving mechanism,
Place a pinhole on the intermediate image plane in the laser irradiation optical system,
It is characterized in that the laser beam is moved by moving the pinhole. Further, the laser beam moving mechanism is characterized in that the laser beam is moved by moving a laser emitting lens. Further, as the laser beam moving mechanism, an optical system for limiting the beam shape of the emitted laser beam by a pinhole is used, and the laser beam is moved by moving the pinhole. Further, an optical system for detecting a position change of the probe mounting portion is provided, and based on the position change of the probe mounting portion detected by this optical system, a laser beam of the probe displacement detection optical system or this Laser beam of the probe displacement detection optical system and the laser beam of the probe displacement signal caused by the change of the position and angle of the probe mounting part by scanning the probe are irradiated with the laser beam. It is characterized in that the laser light of the optical system to be detected is moved. Further, as a position change detection system of the probe mounting portion, a laser beam for detecting the probe mounting portion position is irradiated onto the probe mounting portion and is condensed, and the laser beam moves to the focal position at right angles to each direction. Forming a position detection reflection surface each grooved in the direction forming the, and irradiating the laser light at the center of each groove, the change of the position of the probe mounting portion from the intensity pattern of the reflected light. Detecting, or forming a position detection reflective surface provided with a cross-shaped groove along a direction perpendicular to each direction in which the laser moves, irradiating the laser light to the center of the cross-shaped groove, The change in the position of the probe mounting portion is detected from the intensity pattern of the reflected light. Further, as a position change detection system of the probe mounting portion, a reflection pattern which is axisymmetric with respect to a direction perpendicular to each direction in which the laser beam moves is formed on the probe mounting portion, and an image of the pattern is formed. The image forming optical system is configured to detect the change in the position of the probe mounting portion from the change in the position of the image.

[0007]

[Function] In addition to the optical system for detecting the displacement of the probe, the error of the probe displacement signal caused by the change in the angle or position caused by scanning the probe is detected by irradiating the probe mounting portion with laser light. By providing the optical system that does, it is possible to detect and correct the above error component even when the probe is scanned.
It is not necessary to move the sample by the actuator, and the wafer size sample can be handled as it is.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the probe scanning microscope of the present invention. In FIG. 1, the laser light source 7 emits a first laser beam 71 for detecting the displacement of the probe and a second laser beam 72 for detecting a change in the angle or position of the probe mounting portion.
The first laser beam 71 irradiates the cantilever-shaped probe 1 with the second laser beam 71.
The laser light 72 is applied to the reflecting surface provided on the probe mounting portion 3. The reflected light of the first laser light 71 is incident on the first photodiode 8, and the reflected light of the second laser light 72 is incident on the second photodiode 9. Each of the first and second photodiodes 8 and 9 is vertically divided into two. The outputs of the first and second photodiodes 8 and 9 are
The first and second subtractors 101 and 111 and the first and second adders 102 and 1 in the first and second displacement detection circuits 10 and 11, respectively.
12 and the respective outputs are input to the first and second dividers 103 and 113. The outputs of the first and second dividers 103 and 113 are input to the displacement signal correction circuit 12. The output of the displacement signal correction circuit 12 is the servo circuit 13
To the high voltage amplifier circuit 14
Is input to the Z actuator 6. Further, the output of the servo circuit 13 is A / D converted by the A / D converter 152 attached to the computer 15, and is taken into the computer 15. The D / A converter 151 attached to the computer 15 inputs the scanning signals in the X and Y directions from the computer 15 to the X, Y actuators 4 and 5 via the high voltage amplifier circuit 14. In addition,
Reference numeral 2 is a sample for measuring the shape and the like.

In such a structure, the probe 1 and the sample 2
Can be brought close to a minute distance where a force such as an atomic force works. The force acting between the probe 1 and the sample 2 deforms the cantilever probe. The deformation is the first laser beam 7
The reflected light from the first probe 1 is received by the first photodiode 8 and the difference in the amount of light incident on each of the two upper and lower detection elements is detected by the first photodiode in the first displacement detection circuit 10.
Subtractor 101 of In addition, the sum of the amounts of light incident on the upper and lower detection elements is obtained by the first adder 102 in the first displacement detection circuit 10. The difference signal of the first subtractor 101 and the sum signal of the first adder 102 are input to the first divider 103 in the first displacement detection circuit 10, and the difference signal is divided by the sum signal for normalization. .

The change in the angle and position of the probe mounting portion 3 is received by the second photodiode 9 by the reflected light of the second laser light 72 from the reflecting surface of the probe mounting portion 3, and the same as above. In addition, the difference and the sum of the amounts of light incident on the upper and lower detection elements are respectively calculated by the second subtractor 111 in the second displacement detection circuit 11,
It is calculated by the second adder 112. The difference signal and the sum signal are input to the second divider 113 in the second displacement detection circuit 11, where the difference signal is divided by the sum signal for normalization.

The displacement signal correction circuit 12 obtains the difference between the output of the first displacement detection circuit 10 and the output of the second displacement detection circuit 11 to obtain the probe attachment portion 3 included in the displacement signal of the probe 1. The displacement signal is corrected by removing the component caused by the change of the angle and position of the.

The servo circuit 13 controls the Z actuator 6 so that the output of the displacement signal correction circuit 12 becomes constant. In this state, the computer 15 outputs scanning signals in the X and Y directions through the D / A converter 151, drives the X and Y actuators 4 and 5 through the high voltage amplifier circuit 14, and drives the probe 1 The sample 2 is scanned, and the output of the servo circuit 13 which is the control signal of the Z actuator 6 at that time is A
The shape of the sample 2 is measured by loading it into the computer 15 by the / D converter 152.

In order to accurately correct the change in the position of the probe mounting portion 3, the angle of the laser beam reflecting surface of the probe 1 and the probe mounting portion 3 in the plane where the probe 1 is deformed, and It is necessary to make the incident angles of the laser light equal. When the size of the optical component is limited, the positions and angles of both optical systems are shifted in the direction perpendicular to the plane.

As described above, according to the above-described embodiment, in addition to the optical system for detecting the displacement of the probe, the error of the probe displacement signal caused by the change in the angle or position caused by scanning the probe is detected. Since it is configured to have an optical system that applies a laser beam to the needle mounting portion to detect it, even when the probe is scanned, it is possible to detect the error component and correct the probe displacement signal.
It is not necessary to move the sample by the actuator, and the wafer size sample can be handled as it is. Moreover, since the optical lever method is used as the displacement detection method of the probe,
High-resolution measurement is possible. Furthermore, when a photodiode such as a two-divided photodiode is used as the detection element, the displacement signal of the probe and the signal of the change in the angle or position of the probe attachment portion are divided by the total light amount incident on each detection element, Since it is configured to be normalized, accurate measurement can be performed without being affected by the difference in the amount of light generated between the optical systems due to the amount of light of the laser, the reflectance of the reflecting surface, etc., and the change in the amount of light emitted from the laser. .

FIG. 2 is a block diagram showing a second embodiment of the probe scanning microscope of the present invention. In FIG. 2, the same elements as those in FIG. 1 are designated by the same reference numerals and duplicate description will be omitted. In FIG. 2, the laser light source 7 emits a first laser light 71 for detecting the displacement of the probe and a second laser light 72 for detecting a change in the angle or position of the probe mounting portion 3. The emitted laser light is applied to the reflecting surfaces of the probe 1 and the probe mounting portion 3 via the laser beam moving device 16. Further, the scanning signals in the X and Y directions output from the computer 15 are input to the laser light moving device control circuit 17, and the output thereof is input to the laser light moving device 16.

In such a structure, the probe 1 and the sample 2
Can be brought close to a minute distance where a force such as an atomic force works. The force acting between the probe 1 and the sample 2 deforms the cantilever probe. The deformation is the first laser beam 7
The reflected light from the first probe 1 is received by the first photodiode 8 and the difference in the amount of light incident on each of the two upper and lower detection elements is detected by the first photodiode in the first displacement detection circuit 10.
Subtractor 101 of In addition, the sum of the amounts of light incident on the upper and lower detection elements is obtained by the first adder 102 in the first displacement detection circuit 10. The difference signal of the first subtractor 101 and the sum signal of the first adder 102 are input to the first divider 103 in the first displacement detection circuit 10, and the difference signal is divided by the sum signal for normalization. .

The change in the angle and position of the probe mounting portion 3 is received by the second photodiode 9 by the reflected light of the second laser light 72 from the reflecting surface of the probe mounting portion 3, and the same as above. In addition, the difference and the sum of the amounts of light incident on the upper and lower detection elements are respectively calculated by the second subtractor 111 in the second displacement detection circuit 11,
It is calculated by the second adder 112. The difference signal and the sum signal are input to the second divider 113 in the second displacement detection circuit 11, where the difference signal is divided by the sum signal for normalization.

The displacement signal correction circuit 12 obtains the difference between the output of the first displacement detection circuit 10 and the output of the second displacement detection circuit 11 to obtain the probe attachment portion 3 included in the displacement signal of the probe 1. The displacement signal is corrected by removing the component caused by the change of the angle and position of the.

The servo circuit 13 controls the Z actuator 6 so that the output of the displacement signal correction circuit 12 becomes constant. In this state, the computer 15 outputs scanning signals in the X and Y directions through the D / A converter 151, drives the X and Y actuators through the high voltage amplifier circuit 14, and moves the probe 1 onto the sample 2. Scan, and the output of the servo circuit 13 which is the control signal of the Z actuator 6 at that time is A / D
The shape of the sample 2 is measured by loading it into the computer 15 by the converter 152.

The scanning signals in the X and Y directions output from the computer 15 via the D / A converter 151 are
It is input to the laser light moving device control circuit 17, and the laser light moving device 16 is driven according to the signal, and the first and second laser light moving devices are driven.
The laser beams 71 and 72 of 1 move so as to follow the probe 1 to be scanned.

Here, specific examples of the laser beam moving device used in the device of FIG. 2 are shown in FIGS. What is shown in FIG.
A mirror is arranged in the laser irradiation optical system, and the angle of the mirror is changed to move the laser light. In FIG. 3, the first and the first emitted from the laser light source 7
The second laser beams 71 and 72 are used as X and Y galvanometer scanner mirrors 161 and 1 in the laser beam moving device 16.
It reflects at 62. A control signal corresponding to the scanning signal of the probe 1 is input from the laser light moving device control circuit 17 to the X and Y galvanometer / scanner mirrors 161 and 162, respectively, and the angle of the mirror is changed. As a result, the incident angles of the first and second laser beams 71 and 72 on the lens 163 change, and the first and second laser beams 71 and 72 move so as to follow the movement of the probe 1.

In FIG. 4, a photoacoustic element is arranged in the laser irradiation optical system, and the diffraction angle of the laser beam is changed by this photoacoustic element to move the laser beam. In FIG. 4, the first and second laser beams 71 and 72 emitted from the laser light source 7 are the laser beam moving device 1
The first lens 163 in 6 collimates the light. next,
In the X and Y photoacoustic elements 165 and 166, the transverse ultrasonic waves propagating inside are diffracted, and only the first-order diffracted light is transmitted therethrough. A control signal corresponding to the scanning signal of the probe 1 is input to the X and Y photoacoustic elements 165 and 166 from the laser light moving device control circuit 17, and the frequency of the transverse ultrasonic wave propagating inside each is changed. Then the first
By changing the diffraction angle of the second laser light 71, 72,
The angle of incidence on the lens 164 is changed. As a result, the first and second laser beams 71 and 72 move so as to follow the movement of the probe 1.

In FIG. 5, a pinhole is arranged on the intermediate image plane in the laser irradiation optical system, and the laser beam is moved by moving the pinhole. In FIG. 5, the laser light 70 emitted from the laser light source 7 is condensed by the first lens 163 on the pinhole plate 169 provided at the focal position of the second lens 164 in the laser light moving device 16. To do. The pinhole plate 169 is provided with two pinholes, and the first and second laser beams 71 and 72 are emitted from the pinholes, transmitted through the second lens 164, and emitted. The pinhole plate 169 is attached to the X, Y actuators 167, 168, and the X, Y actuators 167, 168 are driven by a control signal according to the scanning signal of the probe 1 input from the laser light moving device control circuit 17. It moves by being driven. Thereby, the first and second laser beams 7
1, 72 move so as to follow the movement of the probe 1.

In FIG. 6, the laser light is moved by moving the laser emitting lens. In FIG. 6, the first and second laser lights 71 and 72 emitted from the laser light source 7 are the laser light moving device 1
The light is emitted through the lens 163 in the lens 6. Lens 163
Is attached to the X, Y actuators 167, 168, and the X, Y actuators 167, 168 are driven by a control signal according to the scanning signal of the probe 1 input from the laser light moving device control circuit 17. To move. As a result, the first and second laser beams 71 and 72 move so as to follow the movement of the probe 1.

FIG. 7 shows an optical system in which the shape of laser light is restricted by a pinhole so that the laser light is moved by moving the pinhole. In FIG. 7, the laser light 70 emitted from the laser light source 7 is applied to the pinhole plate 169 in the laser light moving device 16. The pinhole plate 169 is provided with two pinholes from which the first and second laser beams 71 and 72 are emitted. The pinhole plate 169 is
The X, Y actuators 167, 168 are attached to the X, Y actuators 167, 168, and the X, Y actuators 167, 168 are driven by a control signal according to the scanning signal of the probe 1 input from the laser light moving device control circuit 17. Moving.
As a result, the first and second laser beams 71, 72 are emitted from the probe 1
Move to follow the movement of.

As described above, according to the above-described embodiment, in addition to the optical system for detecting the displacement of the probe, the error of the probe displacement signal caused by the change in the angle or position caused by scanning the probe is detected. In addition to having the effect of the first embodiment, it is configured to have an optical system that applies laser light to the needle mounting portion for detection, and to move the position where the laser light strikes according to the movement of the probe. Even if the probe is moved over a wide range, the laser light follows and moves, which has the effect of enabling measurement over a wider range than in the past.

Next, FIG. 8 is a constitutional view showing a third embodiment of the probe scanning microscope of the present invention. Here, the first,
In the second embodiment, in addition to the probe displacement detection optical system,
An error caused by a change in the position or angle of the probe mounting portion is detected by applying a laser beam to the probe mounting portion and reflecting the light. Further, the laser beam is moved based on the scanning signal of the probe so that the laser beam may strike the probe even when the probe is scanned greatly. However, most of the actuators used to scan the probe use a piezoelectric element, and there is nonlinearity between the scanning signal and the actual travel distance, so that the laser beam can be accurately projected onto the probe. It was difficult to guess. The third embodiment also solves this problem.
Note that, in FIG. 8, the same elements are denoted by the same reference numerals, and overlapping description will be omitted.

In FIG. 8, the laser light source 7 emits a first laser beam 71 for detecting the displacement of the probe, a second laser beam 72 for detecting the change in the angle and position of the probe mounting portion 3, and a probe 72. The third laser light 73 for detecting the position change of the needle mounting portion 3 is emitted. The emitted laser light is reflected by the half mirror 19,
The first laser light 71 is passed through the laser light moving device 16 and the lens 20 to the cantilever-shaped probe 1 and the second laser light 71, respectively.
Laser beam 72 is on the reflection surface (for correcting the probe displacement) provided on the probe mounting portion 3, and the third laser light 73 is on the reflection surface (the probe mounting portion position detection) provided on the probe mounting portion 3. for)
Is irradiated. The reflected light of the first and second laser lights 71 and 72 is incident on the first and second photodiodes 8 and 9, and the same operation as that of the above-described embodiment is performed. Further, the reflected light of the third laser light 73 is reflected by the lens 20 and the laser light moving device 1.
6, incident on the probe attachment part position detection device 18 via the half mirror 19. Probe attachment part position detector 18
The position of the probe mounting portion 3 detected in step 3 is input to the laser beam moving device control circuit 17, and its output is input to the laser beam moving device 16.

In such a structure, the third laser beam 73 is reflected by the reflecting surface for detecting the probe position provided in the probe mounting portion 3, and the reflected light causes the probe mounting portion position detecting device 18 to reflect the reflected light. A deviation between the position of the probe mounting portion 3 and the position of the third laser light 73 is detected. In the laser beam moving device control circuit 17, the position of the probe attachment part 3 detected by the probe attachment part position detection device 18 and the third laser beam 73 are detected.
The laser beam moving device 16 is driven so that the third laser beam 73 is always radiated to a predetermined position of the probe mounting portion 3 based on the displacement of the position.

Here, a concrete example of the probe attachment portion position detecting device used in the device of FIG. 8 is shown in FIG. Note that, in FIG. 9, a first laser beam 71 and a second laser beam 72 are shown in order to show the relationship between the third laser beam 73 used for detecting the probe attachment portion position and the probe attachment portion position detection device 18. Those not related to the operation of the probe attachment portion position detection device 18, such as, will be omitted.

The one shown in FIG. 9 (a) is the probe mounting portion 3
As a position change detection system of No. 3, a laser beam 73 for detecting the position of the probe mounting portion is radiated onto the probe mounting portion 3 and condensed, and a cross is formed along the direction perpendicular to each direction in which the laser moves to the focal position. Forming a position detection reflective surface with a groove
Laser light is applied to the center of the cross-shaped groove, and a change in the position of the probe mounting portion 3 is detected from the intensity pattern of the reflected light. In FIG. 9A, the third laser light 73 emitted from the laser light source is the half mirror 19,
After passing through the laser beam moving device 16, the light is focused on the position detecting reflection surface of the probe mounting portion 3 by the lens 20. The position detecting reflection surface of the probe mounting portion 3 has a width of about the spot diameter of the third laser beam 73 on the position detecting reflection surface of the probe mounting portion 3 and a depth of the third laser beam. 1/8 of the wavelength of light 73
A cross groove of about a degree is formed. The reflected light from the reflecting surface (cross groove) is reflected by the lens 20 and the laser beam moving device 1.
After passing through 6, the light is reflected by the half mirror 19, bent at a right angle, and enters the four-divided photodiode 181. When the third laser light 73 deviates from the center of the cross groove, it undergoes asymmetric diffraction on the incident optical axis, and the intensity pattern of the far-field image of the reflected light also changes. The change is calculated by the probe attachment portion position detection circuit 182 by calculating the difference in the amount of light incident on each detection element of the four-division photodiode 181. As the calculation, assuming that the respective light amounts are a, b, c, and d, the components in the two directions orthogonal to each other by ((a + b)-(c + d)) / (a + b + c + d) ((a + d)-(b + c)) / (a + b + c + d) are calculated. You can ask. The laser beam moving device control circuit 17 drives the laser beam moving device 16 so that this value becomes the minimum.

The one shown in FIG. 9B is the probe mounting portion 3
As a position change detection system of the above, an imaging optical system is formed on the probe mounting portion 3 to form a reflection pattern axially symmetric with respect to a direction perpendicular to each direction in which the laser moves and form an image of the pattern. The change in the position of the probe mounting portion 3 is detected from the change in the image position. In FIG. 9B, the third laser light 73 emitted from the laser light source is
Half mirror 19, laser beam moving device 16, lens 20
After that, the probe mounting portion 3 is irradiated. Tip attachment part 3
Is attached with a prism, and a circular reflection pattern is formed on the upper surface of the prism. The opposite surface is a reflecting surface for correcting the probe displacement. A part of the irradiated light is reflected by this reflection pattern, and the reflected light passes through the lens 20 and the laser light moving device 16 and then passes through the half mirror 1.
The light is reflected at 9, is bent at a right angle, and is condensed on the 4-division photodiode 181 by the second lens 183. When the center of the third laser light 73 deviates from this circular reflection pattern, the position of the reflection pattern image formed on the four-division photodiode 182 is also displaced by the second lens 183. The shift is taken as the four-division photodiode 181
The difference in the amount of light incident on each of the detection elements is calculated and calculated by the probe attachment portion position detection circuit 182. As the calculation, assuming that the respective light amounts are a, b, c, and d, the components in the two directions orthogonal to each other by ((a + b)-(c + d)) / (a + b + c + d) ((a + d)-(b + c)) / (a + b + c + d) are calculated. You can ask. The laser beam moving device control circuit 17 drives the laser beam moving device 16 so that this value becomes the minimum. The reflected light from the reflecting surface for correcting the probe displacement formed on the surface of the probe mounting portion 3 opposite to the reflection pattern of the prism is used as the reflected light of the second laser beam 72 in FIG.

In the configuration of FIG. 9, the laser beam is taken into the probe attachment portion position detecting device 18 only by the half mirror 19, but by combining the polarization beam splitter and the wave plate, etc., a laser light source can be obtained with high efficiency. It is possible to construct an optical system with little returning light. Further, when the actuator has non-linearity such as hysteresis and the accurate position of the probe cannot be detected, the laser beam moving device 16
The position can be detected from the drive signal to the.

As described above, according to the above embodiment, the positional deviation between the probe mounting portion position detecting laser beam 73 and the probe mounting portion 3 is detected, and the laser beam is moved so as to minimize the displacement. Since the laser beam moves so as to accurately follow the scanning of the probe, it is possible to perform highly accurate measurement even when an actuator having strong nonlinearity is used.

[0035]

As described above in detail with reference to the embodiments, according to the present invention, an optical lever system is used as a probe displacement detection system of a probe scanning microscope in which a probe is attached to an actuator and moved. It is possible to realize a probe scanning microscope with high resolution and a wide measurement area that can handle a large sample such as a wafer.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a probe scanning microscope of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the probe scanning microscope of the present invention.

FIG. 3 is a configuration diagram of a specific example of a laser beam moving device used in the device shown in FIG.

4 is a configuration diagram of a specific example of a laser beam moving device used in the device of FIG.

5 is a configuration diagram of a specific example of a laser beam moving device used in the device shown in FIG.

6 is a configuration diagram of a specific example of a laser beam moving device used in the device of FIG.

7 is a configuration diagram of a specific example of a laser beam moving device used in the device of FIG.

FIG. 8 is a configuration diagram showing a third embodiment of the probe scanning microscope of the present invention.

9 is a configuration diagram of a specific example of a probe attachment portion position detection device used in the device of FIG.

FIG. 10 is a conventional example of an optical lever type probe scanning microscope.

FIG. 11 is a conventional example of a device in which a probe and a displacement detection system are simultaneously moved.

[Explanation of symbols]

 1 probe 2 sample 3 probe attachment part 4 X actuator 5 Y actuator 6 Z actuator 7 laser light source 8, 9 photo diode 10, 11 displacement detection circuit 12 displacement signal correction circuit 13 servo circuit 14 high voltage amplification circuit 15 computer 16 laser light Moving device 17 Laser beam moving device control circuit 18 Probe attachment position detecting device 19 Half mirror 20,183 Lens 71, 72, 73 Laser light 101, 111 Subtractor 102, 112 Adder 103, 113 Divider 151 D / A Converter 152 A / D converter 181 Quadrant photodiode 182 Probe position detection circuit

Claims (11)

[Claims] 1. A cantilever-shaped probe is brought close to a sample up to a minute distance, and a minute force such as an atomic force acting between the two is detected as a displacement of the probe, and the probe is sampled. By scanning on the surface, a probe scanning microscope for measuring the shape and physical properties of the surface of the sample, wherein the probe is attached to an actuator and moved,
In the probe scanning microscope using an optical lever method as a system for detecting the displacement of the probe, in addition to the optical system for detecting the displacement of the probe, the probe by scanning the probe An optical system for detecting an error of a probe displacement signal due to a change in the position or angle of the mounting portion by irradiating the probe mounting portion with a laser beam, and a mounting portion of the probe detected by the detection optical system. And a means for correcting the probe displacement signal detected by the probe displacement detection optical system according to a change in the position or the angle, or both, and a probe scanning microscope. 2. The probe scanning microscope according to claim 1, wherein a split photodiode such as a split photodiode is used as a detection element of both detection optical systems, and the total amount of light incident on the photodiode is used. 2. A probe scanning microscope, characterized in that it is configured to divide the difference signal of the light amount of the detection element. 3. The probe scanning microscope according to claim 1, wherein a laser beam of the probe displacement detection optical system is based on a probe movement signal applied to an actuator to which the probe is attached, Alternatively, the laser beam of the optical system for detecting the error of the probe displacement signal caused by the change of the angle and the position by scanning the laser beam of the probe displacement detection optical system and the probe by applying the laser beam to the probe mounting portion. A probe scanning microscope characterized by having a mechanism for moving light. 4. The probe scanning microscope according to claim 3, wherein a mirror is arranged in the laser irradiation optical system as the laser beam moving mechanism, and the laser beam is moved by changing the angle of the mirror. A probe scanning microscope characterized in that 5. The probe scanning microscope according to claim 3, wherein as the laser beam moving mechanism, a photoacoustic element is arranged in a laser irradiation optical system, and the diffraction angle of the laser beam is changed by the photoacoustic element. The probe scanning microscope is characterized in that the laser light is moved. 6. The probe scanning microscope according to claim 3, wherein as the laser beam moving mechanism, a pinhole is arranged on an intermediate image plane in a laser irradiation optical system, and the laser beam is moved by moving the pinhole. A probe scanning microscope characterized in that the probe is moved. 7. The probe scanning type microscope according to claim 3, wherein the laser beam moving mechanism moves the laser beam by moving a laser emitting lens. microscope. 8. The probe scanning microscope according to claim 3, wherein the laser beam moving mechanism uses an optical system for limiting the beam shape of the emitted laser beam by a pinhole, and moving the pinhole. A probe scanning microscope, wherein the laser beam is moved. 9. The probe scanning microscope according to claim 3, further comprising an optical system for detecting a positional change of the probe mounting portion,
Based on the position change of the probe mounting portion detected in this optical system, the laser beam of the probe displacement detection optical system or the laser beam of the probe displacement detection optical system and the probe by scanning the probe It is characterized in that an error of a probe displacement signal caused by a change in a position or an angle of a mounting portion of the probe is moved by irradiating the probe mounting portion with a laser beam to move a laser beam of an optical system. A scanning probe microscope. 10. The probe scanning microscope according to claim 9, wherein a laser beam for detecting the position of the probe mounting portion is irradiated and condensed on the probe mounting portion as a position change detection system of the probe mounting portion. Then, at the focal position, a reflecting surface for position detection is formed, which is grooved in each direction perpendicular to each direction in which the laser light moves, and the laser light is irradiated to the center of each groove and the reflection Detecting a change in the position of the probe mounting portion from a light intensity pattern, or forming a position detection reflective surface having a cross-shaped groove along a direction perpendicular to each direction in which the laser moves, The probe scanning microscope, wherein the center of the cross-shaped groove is irradiated with the laser light, and a change in the position of the probe mounting portion is detected from the intensity pattern of the reflected light. 11. The probe scanning microscope according to claim 9, wherein a position change detection system of the probe mounting portion is an axis with respect to a direction perpendicular to each direction in which the laser light moves to the probe mounting portion. An imaging optical system that forms a symmetrical reflection pattern and forms an image of the pattern is configured, and a change in the position of the probe mounting portion is detected from a change in the position of the image. A scanning probe microscope.