JP2008003035A - Method for aligning probe end - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately align an end position of a probe, with a targeted measurement starting position of a material, without forming markers on a cantilever. <P>SOLUTION: This probe end aligning method is equipped with an acquisition process for previously acquiring data on the external profile line of the cantilever and on the probe end position; a generation process for extracting the end position P2 and the profile line P3 of the cantilever from the acquired data, a guidance marker M is generated by together combining them with their relative positional relations associated with each other; a determination process for determining the measurement starting position P1 from an observation image of the specimen; a first display process for displaying the guidance marker so that it is superimposed on the image, with the end position coinciding with the starting position; a second display process for observing the cantilever, while the observation image of the cantilever is displayed in the image; and an adjustment process for adjusting the position of the cantilever so as to make it coincide with the profile line. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a probe tip alignment method for aligning a probe tip of a scanning probe microscope with a measurement start position.

As is well known, a probe with a pointed tip is brought close to the nm order with respect to various samples such as metals, semiconductors, ceramics, resins, polymers, biomaterials and insulators, and the probe and sample at that time 2. Description of the Related Art A scanning probe microscope (SPM) is known as an apparatus that measures the shape of a sample surface and the like at an atomic dimension level by measuring the interaction between the two.
The maximum measurement range of this scanning probe microscope is several tens of μm. Therefore, when observing a micro area in a large sample, it is impossible to visually align the tip of the probe with the micro area to be observed. Accordingly, the normal scanning probe microscope includes a stage for moving the sample and an optical observation device such as an optical microscope having a field of view larger than the SPM measurement range.

Thus, by combining the scanning probe microscope and the optical observation device, the cantilever supporting the probe can be observed by the optical observation device, so that the probe is aligned with the target position on the sample. Can do.
However, since the optical observation device is disposed above the probe and the cantilever, only the back surface of the cantilever can be observed. For this reason, the probe formed on the opposite side cannot be directly observed with an optical observation device, and it is difficult to accurately identify the tip position of the probe.

Therefore, various methods have been conventionally considered in order to solve such a problem and accurately specify the tip position of the probe. For example, what has a marker indicating the position of the probe on the back surface of the cantilever is known (see, for example, Patent Document 1 and Patent Document 2). This marker is provided at a position facing the probe, and is, for example, a protrusion or a dent. The position of the probe can be specified even from the back side of the cantilever by checking the marker with an optical observation device.
Japanese Patent Laid-Open No. 3-102209 JP 2003-315238 A

However, the above conventional methods still have the following problems.
That is, in the conventional method, it is necessary to accurately provide a marker on the back surface of the cantilever so as to face the probe. However, in practice, it is difficult to manufacture while accurately aligning the positions. In general, when manufacturing a probe having a probe and a cantilever, it is manufactured from a semiconductor substrate by performing etching processing using a photoresist film a plurality of times. Since these are on the opposite side, they cannot be formed at the same time using the same photoresist film, or can be formed from the same direction side. For this reason, positional displacement is inevitably caused, and the marker cannot be accurately aligned with the position facing the probe.
In addition, since the number of manufacturing steps is inevitably increased, it takes time and labor, and the manufacturing cost cannot be kept low.

  Further, as shown in FIG. 8, the normal cantilever is attached with an angle of tens of degrees with respect to the stage. For this reason, even if the optical axis of the optical observation apparatus is aligned with the marker, an error occurs because the actual tip position of the probe does not exist on the optical axis. For example, as shown in FIG. 8, when the probe length L is 60 μm and the cantilever attachment angle θ is 15 °, the error X between the marker and the tip position of the probe is X = L sin θ = It will be about 15.5 μm. Therefore, even if there is a marker, the tip position of the probe cannot be accurately specified from the cantilever side. In particular, since the probe used for driving in liquid or the like is designed to be long in order to suppress the influence of damping, the above-described error X is larger.

  Further, for detecting the displacement of the cantilever, an optical lever method for detecting a laser beam reflected on the back surface of the cantilever is generally used. However, if a marker is provided on the back surface of the cantilever, the laser beam may be irregularly reflected by this marker, which may adversely affect displacement detection. In particular, in a cantilever where the thickness of the cantilever is thin and allows laser light to pass therethrough, it is efficient to irradiate the laser light to a position where the thickness is as large as possible, that is, the back surface of the portion where the probe is formed. However, as described above, if there is a marker at this position, the reflection efficiency of the laser beam is impaired, and displacement detection is adversely affected.

  The present invention has been made in consideration of such circumstances, and its purpose is to accurately align the tip position of the probe with the target measurement start position of the sample without forming a marker on the cantilever. It is an object of the present invention to provide a method for aligning a probe tip that can be performed.

In order to achieve the above object, the present invention provides the following means.
The probe tip alignment method of the present invention is a probe tip alignment method in which the tip position of a probe formed at the tip of a cantilever is aligned with a target measurement start position on a sample, An acquisition step of acquiring data of the outline contour line of the cantilever and the tip position of the probe, and after the acquisition step, extracting the tip position of the probe and the geometric feature point of the cantilever from the acquired data A generation step of generating a guide marker in which the tip position of the probe and the geometric feature point are combined in a state in which the relative positional relationship is associated with each other, and after the generation step, the sample is optically observed A step of displaying an observation image on a monitor and specifying the measurement start position from the observation image; and the guide marker at the specified measurement start position after the specification step A first display step of displaying the guide marker superimposed on the observation image in a state where the tip positions of the probes are matched; and after the first display step, the optical axis is the same as that in the specific step. A second display step of optically observing the cantilever and displaying an observation image of the cantilever on the observation image; and after the second display step, while confirming the observation image, And an adjusting step for adjusting the position of the cantilever so as to coincide with the feature point.

  In the probe tip alignment method according to the present invention, first, the outer contour line of the cantilever and the probe tip position data are respectively acquired in the acquisition step. At this time, data may be acquired by imaging the cantilever from the side on which the probe is formed, or may be acquired from design data that designed the cantilever. Next, from the acquired data, the tip position of the probe and the geometric feature point of the cantilever (the geometric feature point in the present invention is a point where the position can be specified among the graphic elements constituting the acquired outline contour line. (For example, an intersection, one side, etc.) are extracted, and a generating step of generating a guide marker by combining them in a state where their relative positional relationships are associated with each other is performed.

  Next, the sample is optically observed with an optical microscope or the like, and an observation image is displayed on the monitor. And the specific process which specifies a measurement start position based on this observation image is performed. Next, a first display step is performed in which a guide marker is displayed at the specified measurement start position while being superimposed on the observation image. At this time, the display is performed in a state where the tip position of the probe of the guide marker coincides with the measurement start position. Thereby, the specified measurement start position can be indicated by the guide marker.

Next, a second display step is performed in which the cantilever is optically observed with the same optical axis as when the sample is observed, and an observation image of the cantilever is displayed on the observation image. Thereby, a sample, a guide marker, and a cantilever are displayed on an observation image. Then, while confirming this observation image, an adjustment step is performed in which the cantilever is appropriately moved toward the guide marker to adjust the position so that the cantilever coincides with the geometric feature point of the guide marker.
Here, the geometric feature point displayed as the guide marker and the tip position of the probe are generated in a state where their relative positional relationships are associated with each other. By matching the feature points, the actual tip position of the probe can be accurately aligned with the measurement start position. As a result, a more accurate sample measurement can be performed.

  As described above, according to the probe tip positioning method according to the present invention, even if the tip position of the probe cannot be confirmed behind the cantilever shadow, the guide marker is used to obtain the target measurement position. In addition, the tip position of the probe can be accurately aligned. Further, unlike the prior art, since it is not necessary to form a marker or the like on the cantilever itself, the manufacturing cost necessary for forming the marker can be eliminated. Furthermore, since it is not necessary to form a marker on the cantilever itself, there is no adverse effect on the laser beam when measuring the deflection of the cantilever by the optical lever method. Therefore, the displacement detection of the cantilever can be performed with high accuracy.

  Further, the probe tip alignment method of the present invention is the above-described probe tip alignment method of the present invention, wherein the geometric feature point extracts two intersection points where at least sides intersect each other from the outline. The guide marker is generated by combining the extracted intersection point and the tip position of the probe.

In the probe tip alignment method according to the present invention, when performing the generation process, two intersections where at least the sides intersect are extracted from the acquired contour data, and these are used as geometric feature points. . Then, a guide marker is generated by combining the position of the intersection and the tip position of the probe in a relatively associated state. In other words, when the guide marker is displayed in the first display step, the tip position of the probe tip of the guide marker is displayed at the specified measurement start position, and at least two intersections are displayed around it.
The actual tip position of the probe can be made to coincide with the tip position of the probe of the guide marker by matching the intersection point of the actual cantilever with the displayed two intersection points. As a result, the actual tip position of the probe can be accurately aligned with the measurement start position.

  Further, the probe tip alignment method of the present invention is the above-described probe tip alignment method of the present invention, wherein the geometric feature point is obtained by extracting at least one side from the outline. The guide marker is generated by combining the extracted one side and the tip position of the probe.

In the probe tip positioning method according to the present invention, at the time of performing the generation step, at least one side is extracted from the acquired outline contour data, and this is used as a geometric feature point. Then, a guide marker is generated by combining the position of one side and the tip position of the probe in a relatively associated state. That is, when the guide marker is displayed in the first display step, the tip position of the probe tip of the guide marker is displayed at the specified measurement start position, and at least one side is displayed around it.
Then, by matching one side of the actual cantilever with this one side displayed, the tip position of the actual probe can be matched with the tip position of the probe of the guide marker. As a result, the actual tip position of the probe can be accurately aligned with the measurement start position.

  Further, the probe tip alignment method of the present invention is the above-described probe tip alignment method of the present invention, wherein the geometric feature point is the outline contour itself, and the guide marker is extracted. It is generated by combining an outer contour line and the tip position of the probe.

In the probe tip alignment method according to the present invention, when performing the generation process, the outline contour itself is extracted from the acquired outline contour data, and this is used as a geometric feature point as it is. Then, a guide marker is generated by combining the outline contour line and the tip position of the probe in a relatively associated state. That is, when the guide marker is displayed in the first display step, the tip position of the probe tip of the guide marker is displayed at the specified measurement start position, and the outer contour line is displayed around it.
Then, by matching the actual contour of the cantilever with the displayed contour contour, the tip position of the actual probe can be matched with the tip position of the probe of the guide marker. As a result, the actual tip position of the probe can be accurately aligned with the measurement start position. In particular, since the contour outline of the cantilever is displayed as it is, it is easy to align the cantilever, and more accurate alignment can be performed.

  Further, the probe tip alignment method of the present invention is the probe tip alignment method of any one of the above-described present invention, wherein the generating step orthogonalizes the acquired outline contour data to the optical axis. A correction step of correcting the state of projection on the plane and correcting the acquired data of the tip position of the probe on the plane based on the mounting angle of the cantilever and the length of the probe. The guide marker is formed by extracting the tip position of the probe and the geometric feature point from the corrected data after the correction step.

In the probe tip positioning method according to the present invention, the tip position of the probe is more accurately aligned with the measurement start position of the sample no matter what angle the cantilever is attached to the sample. be able to.
In other words, when the cantilever is attached with an angle with respect to a plane perpendicular to the optical axis, the outer contour line of the cantilever and the tip position of the probe have no angle when viewed from the optical axis direction. It will shift compared to the state. Therefore, when performing the generation process, a correction process for correcting this deviation is performed.

  That is, first, the outline contour data acquired in the acquisition process is corrected to a state projected onto a plane orthogonal to the optical axis. At the same time, the data on the tip position of the probe acquired in the acquisition process is corrected to a state in which it is projected onto a plane orthogonal to the optical axis based on the mounting angle of the cantilever and the length of the probe. Even if the cantilever is attached to the plane perpendicular to the optical axis by this correction step, it is possible to correct the deviation that occurs when viewed from the optical axis direction.

  Then, the tip position of the probe and the geometric feature point are extracted from the corrected data, and a guide marker that associates these relative positional relationships is generated. As a result, by aligning the actual cantilever with the displayed geometric feature point, no matter what angle the cantilever is mounted, the actual tip of the actual probe The tip position can be matched. As a result, the actual tip position of the probe can be accurately aligned with the measurement start position.

  According to the probe tip alignment method of the present invention, the tip position of the probe can be accurately aligned with respect to the measurement start position aimed at by the sample without forming a marker on the cantilever.

Hereinafter, an embodiment of a probe tip positioning method according to the present invention will be described with reference to FIGS. In the present embodiment, a case where alignment is performed using a scanning probe microscope having a self-sensing probe will be described as an example.
As shown in FIG. 1, the scanning probe microscope 1 includes a cantilever 2b that is arranged above a sample S and has a probe 2a at the tip, and a main body that cantileverally supports the proximal end of the cantilever 2b. 2c, a cantilever drive unit 3 that relatively moves the sample S and the probe 2, an optical microscope 4 that optically observes the cantilever 2b and the sample S on the same optical axis, and the optical microscope 4 The monitor 5 which displays the observation image observed by (1), and the control part 6 which controls these each component and each component mentioned later comprehensively are provided.

  The sample S is placed on a sample driving unit 10 that moves in three directions, ie, an XY direction parallel to the sample surface S1 and a Z direction parallel to the sample surface S1. The sample driving unit 10 is a piezoelectric element made of, for example, PZT (lead zirconate titanate) or the like, and is configured to slightly move the sample S in the XYZ directions based on an instruction from the control unit 6. Note that the sample driving unit 10 of this embodiment is used when measuring the sample S. The sample driving unit 10 is attached on the housing 11.

  The casing 11 includes a bottom plate portion 11a on which the sample driving unit 10 is placed, a side wall portion 11b extending upward from both ends of the bottom plate portion 11a, and a ceiling provided at the upper end of one side wall portion 11b. It is comprised integrally with the board part 11c. The optical microscope 4 is attached to the top plate portion 11c, and the cantilever 2b and the sample S can be optically observed through an opening 12a of the holder body 12 described later. Further, the optical microscope 4 outputs the observed observation image to the control unit 6, and displays the observation image sent by the control unit 6 on the monitor 5.

A holder main body 12 is attached to the upper end of the other side wall portion 11 b of the case 11 via the cantilever driving portion 3. This holder main body 12 is formed in a plate shape toward one side wall portion 11b of the housing 11, and an opening 12a for securing the optical path of the optical microscope 4 is formed in a substantially intermediate portion. In addition, the probe 2 is detachably fixed to the lower surface of the holder body 12 via a slope block 13.
The cantilever drive unit 3 is a piezoelectric element made of, for example, PZT (lead zirconate titanate) or the like, similar to the sample drive unit 10 described above, and is probed via the holder body 12 based on an instruction from the control unit 6. 2 is moved minutely in the XYZ directions. In addition, the cantilever drive part 3 of this embodiment is used when aligning the tip of the probe 2a.

The probe 2 is a self-sensing probe, and a piezoresistive element 14 is provided on the proximal end side of the cantilever 2b. And the piezoresistive element 14 outputs the electrical signal according to the bending of the cantilever 2b to the control part 6 as an output signal.
Specifically, a bias voltage is applied to the piezoresistive element 14 via a metal wiring (not shown), and an electric signal whose level changes according to the bending of the cantilever 2b, that is, the distortion generated in the piezoresistive element 14, It can be taken out as an output signal. And the control part 6 calculates the bending of the cantilever 2b based on the sent output signal, and measures the sample S.

The control unit 6 displays the observation image sent from the optical microscope 4 on the monitor 5, and the measurement start position P1 of the sample S specified based on the observation image is as shown in FIG. In addition, on the monitor 5, the tip position P2 of the probe 2a and the geometric feature point P3 of the cantilever 2b are displayed on the monitor 5 in a state of being associated with each other while being superimposed on the observation image. I am letting.
In this embodiment, the geometric feature point P3 is the outer contour line P3 of the cantilever 2b, and the guide marker M is the extracted outer contour line P3 and the tip position of the probe (hereinafter referred to as the probe tip position P2). It is assumed that it is generated in combination with

  Further, the control unit 6 observes the cantilever 2b with the optical microscope 4 and controls the cantilever driving unit 3 to move the holder main body 12 and the probe 2 in a three-dimensional direction as appropriate when positioning the tip position of the probe 2a. The outer shape of the cantilever 2b is made to coincide with the outer contour line P3 of the guide marker M. This will be described in detail later.

Next, a probe tip alignment method for aligning the tip position of the probe 2a with the measurement start position P1 of the sample S using the thus configured scanning probe microscope 1 will be described.
The probe tip alignment method of the present embodiment is a method of performing alignment by sequentially performing an acquisition process, a generation process, a specifying process, a first display process, a second display process, and an adjustment process. Hereinafter, each of these steps will be described in detail.

  First, an acquisition step of acquiring data of the outer contour P3 of the cantilever 2b and the probe tip position P2 is performed. For example, before fixing the probe 2 to the slope block 13, data is acquired by imaging the cantilever 2b from the side where the probe 2a is formed. Alternatively, data is acquired in advance from design data for designing the probe 2. At this time, the acquired data is stored in the data acquisition unit 6 a incorporated in the control unit 6.

After this acquisition step, the probe tip position P2 and the geometric feature point P3 of the cantilever 2b, that is, the outer contour line P3, are extracted from the acquired data, and the probe tip position P2 and the outer contour line P3 are extracted. A generation step of generating the guide marker M combined in a state in which the relative positional relationships are associated with each other is performed.
That is, the generation unit 6b incorporated in the control unit 6 extracts the probe tip position P2 and the outer contour line P3 of the cantilever 2b from the data stored in the data acquisition unit 6a. As shown, a guide marker M is generated by combining these in a state where their relative positional relationships are associated with each other.

  After this generation process is completed, the sample S is optically observed to display an observation image on the monitor 5, and a specific process for specifying the measurement start position P1 from the observation image is performed. In addition, after the specifying step, a first display step is performed in which the guide marker M is displayed on the observation image in a state where the probe tip position P2 of the guide marker M coincides with the specified measurement start position P1.

  That is, the surface of the sample S is optically observed by the optical microscope 4 and an observation image is displayed on the monitor 5 as shown in FIG. The operator specifies the measurement start position P1 of the sample S based on this observation image. For example, the identification is performed by clicking on the screen using a mouse or the like. Then, the control unit 6 displays the guide marker M at the specified measurement start position P1 while being superimposed on the observation image. At this time, as shown in FIG. 2A, the probe tip position P2 of the guide marker M is displayed in a state in which the measurement start position P1 is matched. Thereby, the measurement start position P1 of the specified sample S can be indicated by the guide marker M. That is, the probe tip position P2 of the guide marker M is displayed at the specified measurement start position P1, and the outer contour line P3 is displayed around it.

  When the guide marker M is overlaid, for example, the guide marker M may be designed to be displayed when the operator clicks the measurement start position P1, and the guide marker M may be displayed on the monitor 5 in advance. M may be displayed, and after the measurement start position P1 is specified, the guide marker M may be moved and displayed so that the tip probe position P2 is superimposed on the measurement start position P1.

After the generation step and the first display step described above are finished, the second can be used to optically observe the cantilever 2b with the same optical axis as when the sample S is observed, and to display an observation image of the cantilever 2b on the observation image. A display process is performed.
That is, the cantilever 2b is optically observed using the optical microscope 4 again. At this time, observation is performed with the same optical axis as when the sample S was observed earlier. Accordingly, as shown in FIG. 2B, the sample S, the guide marker M, and the cantilever 2b can be displayed on the observation image of the monitor 5.

After the second display step is completed, an adjustment step is performed in which the position of the cantilever 2b is adjusted so as to match the outer contour line P3 of the guide marker M while confirming the observation image of the cantilever 2b.
That is, while confirming the observation image displayed on the monitor 5, the control unit 6 appropriately operates the cantilever driving unit 3 to move the cantilever 2 b and the sample S relatively, and moves the cantilever 2 b toward the guide marker M. To move. Then, as shown in FIG. 2C, the actual outer shape of the cantilever 2b is matched with the displayed outer contour line P3. At this time, the outline contour line P3 and the probe tip position P2 displayed as the guide marker M are generated in a state in which their relative positional relationships are associated with each other, so that the actual contour line P3 of the actual cantilever 2b is By matching the outer shape, the actual tip position of the probe 2a can be matched with the probe tip position P2 of the guide marker M. Thereby, the actual tip position of the probe 2a can be accurately aligned with the measurement start position P1.

  As described above, according to the probe tip alignment method of the present embodiment, even if the tip position of the probe 2a cannot be confirmed behind the cantilever 2b, the guide marker M is used to aim. Further, the tip position of the probe 2a can be accurately aligned with the measurement start position P1. In particular, in the case of the present embodiment, the outline contour line P3 of the cantilever 2b is displayed as the guide marker M, so that the cantilever 2b can be easily aligned and more accurate alignment can be performed. Further, since it is not necessary to form a marker on the cantilever 2b itself as in the prior art, the manufacturing cost necessary for forming the marker can be eliminated.

After the tip position of the probe 2a is aligned with the measurement start position P1 of the sample S, the measurement of the sample S, for example, the surface shape of the sample S is measured. In this case, first, the probe 2a and the sample S are relatively moved by the sample driving unit 10, and scanning of the surface of the sample S is started by the probe 2a. Further, during this scanning, the cantilever 2b tends to bend up and down according to the unevenness of the sample surface S1, so that the resistance value of the piezoresistive element 14 changes. The piezoresistive element 14 outputs an output signal corresponding to this deflection to the control unit 6. The control unit 6 performs feedback control of the sample driving unit 10 in the Z direction so that the output signal becomes constant.
Thereby, it is possible to scan the distance between the probe 2a and the sample S in a state where the deflection of the cantilever 2b is controlled to be constant. Further, the control unit 6 can measure the surface shape of the sample S based on a signal for moving the sample driving unit 10 up and down.

  In particular, according to the scanning probe microscope 1 of the present embodiment, before starting the sample S, the tip position of the probe 2a is accurately aligned with the target measurement start position P1, so that the accurate sample S Can be measured.

In the above embodiment, the self-sensing type probe 2 having the piezoresistive element 14 has been described as an example. However, the cantilever 2b is not bent by the optical lever method as shown in FIG. You may comprise so that it may measure.
That is, the laser light source 20 that irradiates the laser beam L, the half mirror 21 that reflects the irradiated laser beam L toward the reflecting surface (not shown) formed on the back surface of the cantilever 2b through the opening 12a of the holder body 12, Displacement comprising a mirror 22 that reflects the laser light L reflected by the reflecting surface and passing through the opening 12a of the holder body 12 to the laser light receiving unit 23, and a laser light receiving unit 23 that receives the laser light L reflected by the mirror 22 A measuring means 24 may be provided.

  The laser light source 20 is fixed on the holder body 12 via a laser light source driving unit 25 and irradiates the laser light L in a substantially horizontal direction. The half mirror 21 is supported by a gantry (not shown) so as to be disposed between the optical microscope 4 and the cantilever 2b. The mirror 22 is also supported by a gantry (not shown) so as to be adjacent to the half mirror 21. Similarly to the laser light source 20, the laser light receiving unit 23 is fixed on the holder body 12. The laser light receiving unit 23 is, for example, a four-divided photodetector, which detects a change in bending of the cantilever 2b based on the incident position of the laser light L and controls the detected change in bending of the cantilever 2b as a DIF signal. 6 is output. In the case of this optical lever system, the control unit 6 feedback-controls the sample driving unit 10 so that the DIF signal sent in the same manner as the self-sensing probe is constant.

Thus, even if it is an optical lever system, there can exist the same effect as the case of a self-detection type. In particular, according to the probe tip alignment method of the present embodiment, since there is no need to form a marker on the cantilever 2b as in the prior art, when measuring the deflection of the cantilever 2b by the optical lever method, laser light is used. L is not adversely affected. Therefore, the displacement measuring means 24 can measure the displacement of the cantilever with high accuracy.
Further, the laser beam L can be accurately irradiated to a position facing the root of the probe 2a with reference to the probe tip position P2 of the guide marker M.

  Moreover, in the said embodiment, although the outline marker P3 and the probe tip position P2 were combined and it was set as the guide marker M, it is not restricted to this case. The guide marker M may be generated by combining the tip 2 position P2 of the probe 2 and the geometric feature point in a state where the relative positional relationship is related to each other.

For example, as shown in FIG. 5A, as the geometric feature point, a point obtained by extracting three intersections P4 where the sides intersect from the outer contour of the acquired cantilever 2b may be used. The guide marker M in this case is generated by combining the extracted intersection point P4 and the probe tip position P2.
In this case, when the guide marker M is displayed on the monitor 5 in the first display step, as shown in FIG. 5B, the probe tip position P2 of the guide marker M at the specified measurement start position P1. Is displayed, and three intersection points P4 are displayed in the vicinity thereof.
Then, as shown in FIG. 5C, the actual intersection point of the cantilever 2b is made to coincide with the displayed three intersection points P4, so that the probe tip position P2 of the guide marker M is brought into contact with the actual probe 2a. The tip position can be matched. Thereby, the actual tip position of the probe 2a can be accurately aligned with the measurement start position P1.

  Although an example in which three intersection points P4 are extracted is shown here, at least two intersection points P4 may be extracted as geometric feature points. If there are at least two intersection points P4, the cantilever 2b can be accurately aligned, and the same effects as described above can be achieved. However, it is preferable to extract more intersection points P4.

Further, as shown in FIG. 6A, a geometric feature point obtained by extracting at least one side P5 from the acquired outline of the cantilever 2b may be used. The guide marker M in this case is generated by combining the extracted side P5 and the probe tip position P2.
In this case, when the guide marker M is displayed on the monitor 5 in the first display step, as shown in FIG. 6B, the probe tip position P2 of the guide marker M at the specified measurement start position P1. Is displayed, and one side P5 is displayed in the vicinity thereof.
Then, as shown in FIG. 6C, by aligning one side of the actual cantilever 2b with the displayed side P5, the tip position of the actual probe 2a is moved to the probe tip position P2 of the guide marker M. Can be matched. Thereby, the actual tip position of the probe 2a can be accurately aligned with the measurement start position P1.
In this case, as shown in FIG. 6D, a triangular mark connecting both ends of one side P5 and the probe tip position P2 may be used as the guide marker M.

Further, in the above embodiment, as shown in FIG. 7, when the cantilever 2b is attached with a particularly large angle θ with respect to a plane orthogonal to the optical axis, the outer contour line acquired during the acquisition process. Is corrected to a state in which it is projected onto a plane orthogonal to the optical axis, and the acquired data of the probe tip position P2 is orthogonal to the optical axis based on the mounting angle θ of the cantilever 2b and the length of the probe 2a. It is preferable to perform a correction process for correcting the projected state on the plane to be projected, and after the correction process, the probe tip position P2 and the outer contour line P3 are extracted from the corrected data to form the guide marker M.
In FIG. 7, a state where the cantilever 2b is attached along a plane orthogonal to the optical axis and the guide marker M at that time are shown by dotted lines.

  That is, when the cantilever 2b is attached with a particularly large angle θ with respect to the plane orthogonal to the optical axis, the outer contour line P3 of the cantilever 2b and the probe 2a when viewed from the optical axis direction. The tip position is displaced as compared with a state where there is no angle (in the case where the tip is illustrated by a dotted line). Therefore, the correction process for correcting this deviation is performed when the generation process is performed.

  That is, first, the outline contour data acquired in the acquisition process is corrected to a state projected onto a plane orthogonal to the optical axis. At the same time, the tip position data of the probe 2a acquired in the acquisition process is projected onto a plane orthogonal to the optical axis based on the mounting angle θ of the cantilever 2b and the length of the probe 2a. to correct. Even if the cantilever 2b is attached to be inclined with respect to a plane orthogonal to the optical axis, this correction process can correct the deviation that occurs when viewed from the optical axis direction.

  Then, the tip position of the probe 2a and the outline contour line P3, which is a geometric feature point, are extracted from the corrected data, and a guide marker M that associates these relative positional relationships is generated. As a result, by aligning the actual cantilever 2b with the displayed outline P3, no matter what angle the cantilever 2b is attached, the actual probe is positioned at the probe tip position P2 of the guide marker M. The tip position of the needle 2a can be matched. Thus, the actual tip position of the probe 2a can be accurately aligned with the measurement start position P1.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the optical microscope 4 is arranged above the cantilever 2b. However, for example, the optical microscope 4 may be arranged below the sample S and observed from below. Even in this case, the tip position of the probe 2a can be accurately adjusted to the measurement start position P1 using the guide marker M.

It is a block diagram of the scanning probe microscope which concerns on one Embodiment of this invention. It is the figure which showed the observation image displayed on the monitor of the scanning probe microscope shown in FIG. 1, Comprising: (a) is a figure which shows the state which set the guide marker to the measurement start position, (b) is a cantilever further (C) is a figure which shows the state which made the cantilever match the guide marker. It is a figure which shows the guidance marker shown in FIG. It is the figure which showed the modification of a scanning probe microscope, Comprising: It is a figure which shows the scanning probe microscope which measures the displacement of a cantilever by an optical lever system. (A) is a figure which shows an example of another guide marker, (b) is a figure which shows the state which set the guide marker to the measurement start position, (c) is the state which made the cantilever correspond to a guide marker. FIG. (A) is a figure which shows an example of another guide marker, (b) is a figure which shows the state which set the guide marker to the measurement start position, (c) is the state which made the cantilever correspond to a guide marker. (D) is a figure which shows the modification of the guidance marker of (a). It is a figure which shows an example of a guide marker when a cantilever is attached in the state which gave the angle with respect to the plane orthogonal to an optical axis. It is a figure for demonstrating the conventional problem, Comprising: It is a figure which shows the state in which the cantilever is attached in the state which attached the angle.

Explanation of symbols

M Guide marker S Sample P1 Measurement start position P2 Probe tip position (tip position of the probe constituting the guide marker)
P3 Outline outline (geometric feature point)
P4 intersection (geometric feature point)
P5 One side (geometric feature point)
2b Cantilever 2a Probe 5 Monitor

Claims (5)

A probe tip alignment method for aligning the tip position of the probe formed at the tip of the cantilever with the target measurement start position on the sample,
In advance, an acquisition step of acquiring data of the contour outline of the cantilever and the tip position of the probe;
After the acquisition step, the tip position of the probe and the geometric feature point of the cantilever are extracted from the acquired data, and the tip position of the probe and the geometric feature point are relative to each other. A generation step for generating a combined guide marker in an associated state;
After the generating step, the sample is optically observed and an observation image is displayed on a monitor, and a specifying step of specifying the measurement start position from the observation image;
A first display step of displaying the guide marker superimposed on the observation image in a state where the tip position of the probe of the guide marker coincides with the specified measurement start position after the specifying step;
A second display step of optically observing the cantilever with the same optical axis as in the specific step after the first display step, and displaying an observation image of the cantilever on the observation image;
An adjustment step of adjusting the position of the cantilever so as to coincide with the geometric feature point of the guide marker while confirming the observation image after the second display step. How to align the needle tip. The probe tip alignment method according to claim 1,
The geometric feature point is obtained by extracting two intersections where at least sides intersect from the outline line.
The probe tip alignment method, wherein the guide marker is generated by combining the extracted intersection point and the tip position of the probe. The probe tip alignment method according to claim 1,
The geometric feature point is obtained by extracting at least one side from the outline.
The guide tip alignment method, wherein the guide marker is generated by combining the extracted one side and the tip position of the probe. The probe tip alignment method according to claim 1,
The geometric feature point is the outline contour itself,
The guide tip alignment method, wherein the guide marker is generated by combining the extracted outer contour line and the tip position of the probe. In the method for aligning the probe tip according to any one of claims 1 to 4,
The generating step corrects the acquired outline contour data so that it is projected onto a plane orthogonal to the optical axis, and acquires the acquired tip position data of the probe from the mounting angle of the cantilever and the probe. A correction step of correcting the projected state on the plane based on the length of the needle, and after the correction step, the tip position of the probe and the geometric feature point are extracted from the corrected data A method of aligning a probe tip, wherein the guide marker is formed.

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