Scanning probe microscope and control method

Abstract

The present invention provides a scanning probe microscope (SPM) and a control method thereof. The SPM (100) is used to measure a sample (S). The SPM (100) comprises: a sample stage (14) for arranging the sample (S); a probe (3) arranged to face the sample (S); a micro-motion mechanism (12) for performing feedback control in a manner such that the atomic force acting between the probe (3) and the sample (S) becomes fixed, thereby moving the probe (3) relatively along the surface of the sample (S); and an information processing device (20) for stopping the measurement of the sample (S) when the atomic force does not become fixed despite the feedback control.

Description

Technical Field

[0001] The present disclosure relates to a scanning probe microscope and a control method. Background Art

[0002] In the past, a scanning probe microscope (SPM) has been proposed that includes a probe that moves relative to the surface of a sample. For example, the SPM described in Japanese Patent Application Publication No. 2021-004859 includes a control device, a sample stage for arranging a sample, and a probe that moves relative to the surface of the sample. The SPM measures the sample by driving the sample stage along the X-axis, Y-axis, and Z-axis directions. In addition, the control device performs feedback control in such a way that the physical quantity (e.g., atomic force) acting between the probe and the sample becomes fixed. Summary of the Invention

[0003] In the aforementioned SPM measurement of a sample, there are cases where, despite the aforementioned feedback control, the physical quantity acting between the probe and the sample does not become constant. This situation occurs, for example, when the sample contains a convex portion that is too large for the SPM to measure. Continuing to measure with such a convex portion can result in inaccurate results.

[0004] The present invention has been made to solve such a problem, and provides a technique for reducing the occurrence of inaccurate measurement results even when the physical quantity acting between a probe and a sample is not constant.

[0005] The scanning probe microscope disclosed herein is used for measuring a sample. The scanning probe microscope comprises: a sample stage for placing the sample; a probe arranged to face the sample; a first drive mechanism for relatively moving the probe along the surface of the sample by executing a first control so as to keep a physical quantity acting between the probe and the sample constant; and a control device for stopping the measurement of the sample if the physical quantity does not remain constant despite the execution of the first control.

[0006] The control method disclosed herein is a method for controlling a scanning probe microscope. The scanning probe microscope comprises: a sample stage for placing a sample; a probe arranged to face the sample; and a first drive mechanism for relatively moving the probe along the surface of the sample. The control method includes: executing a first control to maintain a constant physical quantity acting between the probe and the sample; and stopping measurement of the sample if the physical quantity does not remain constant despite execution of the first control.

[0007] The above-mentioned objects, features, aspects and advantages and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a diagram schematically showing the structure of the SPM according to the embodiment.

[0009] Figure 2 This is a diagram showing a hardware configuration example of an information processing device.

[0010] Figure 3 This is a diagram showing an example of the measurement range.

[0011] Figure 4 This is a functional block diagram of an information processing device.

[0012] Figure 5 This is a diagram showing a method of detecting the occurrence of thermal drift.

[0013] Figure 6 This is a diagram showing the second control when the sample has excessively large uneven portions.

[0014] Figure 7 This is a flowchart for explaining the operation method of SPM.

[0015] Figure 8 This is a flowchart for explaining the operation method of the SPM according to the third embodiment.

[0016] Figure 9 An example of notification text displayed on the display device is shown.

[0017] Figure 10 An example of notification text displayed in the display area of ​​the display device is shown.

[0018] Figure 11 This is an example of a mode selection screen.

[0019] Figure 12 This is a diagram for explaining a method for predicting the waiting time.

[0020] Figure 13 This is a diagram for explaining thermal drift.

[0021] Figure 14 This is a flowchart for explaining the operation method of the SPM according to the modification.

[0022] Figure 15 This is a flowchart of the standby time calculation process. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and their description will not be repeated.

[0024] [First embodiment]

[0025] Figure 1 This is a diagram schematically showing the structure of a scanning probe microscope (SPM) involved in the embodiment. The scanning probe microscope 100 involved in this embodiment is typically an atomic force microscope (AFM: Atomic Force Microscope) that uses the physical quantity acting between the probe (Probe) 3 and the surface of the sample S to measure the shape of the surface of the sample S. The present disclosure can also be similarly applied to other scanning probe microscopes, such as a scanning tunneling microscope (STM: Scanning Tunneling Microscope). In addition, the physical quantity is, for example, an atomic force (attraction or repulsion). In the following, the height direction of the sample S is set to the Z-axis direction, and the directions orthogonal to the Z-axis direction are set to the X-axis direction and the Y-axis direction.

[0026] like Figure 1 As shown, the scanning probe microscope 100 includes a measuring device 10, an information processing device 20, a display device 30, and an input device 40 as its main components. The measuring device 10 includes an optical system 1, a cantilever 2, a fine motion mechanism 12 (scanner), a sample stage 14, a coarse motion mechanism 13, an XY-direction drive unit 16, a Z-direction drive unit 18, and a feedback signal generator 22 as its main components. The "fine motion mechanism 12" of this embodiment corresponds to the "first drive mechanism" of the present disclosure, and the "coarse motion mechanism 13" of this embodiment corresponds to the "second drive mechanism" of the present disclosure.

[0027] The sample S is arranged on the sample stage 14. The sample stage 14 is arranged on the micro-motion mechanism 12. The micro-motion mechanism 12 is a moving device for changing the relative positional relationship between the sample S and the probe 3. The micro-motion mechanism 12 has an XY scanner 12xy and a Z scanner 12z. The XY scanner 12xy moves the sample stage 14 in the X-axis direction and the Y-axis direction. The Z scanner 12z micro-moves the sample stage 14 in the Z-axis direction. The XY scanner 12xy has a piezoelectric element that is deformed by a voltage applied from the XY direction drive unit 16. The Z scanner 12z has a piezoelectric element that is expanded and contracted by a voltage applied from the Z direction drive unit 18. The Z scanner 12z expands and contracts using this piezoelectric element. In addition, the XY scanner 12xy and the Z scanner 12z are not limited to structures having piezoelectric elements.

[0028] In the present embodiment, when the voltage applied by the Z-direction drive unit 18 is the maximum value Vmax, the sample stage 14 is driven to the highest position in the Z-axis direction. In addition, when the voltage applied by the Z-direction drive unit 18 is the minimum value Vmin, the sample stage 14 is driven to the lowest position in the Z-axis direction. For example, the maximum value Vmax is +V1 (V1 is a positive real number), and the minimum value Vmin is -V1. In addition, when the voltage applied by the Z-direction drive unit 18 is zero, the sample stage 14 is driven to the initial position. In the present embodiment, the initial position is the central position in the Z-axis direction. In addition, as a modified example, when the voltage applied by the Z-direction drive unit 18 is the maximum value Vmax, the sample stage 14 is driven to the lowest position in the Z-axis direction, and when the voltage is the minimum value Vmin, the sample stage 14 is driven to the highest position in the Z-axis direction.

[0029] The cantilever 2 is formed in a leaf spring shape, and one end thereof is supported by the bracket 4. The other end of the cantilever 2 is a free end, which is arranged to face the sample S. Figure 1 In the example shown, the cantilever 2 is positioned upward in the Z-axis direction. The cantilever 2 has a front surface facing the sample S and a back surface opposite the front surface. A probe 3 is positioned on the front surface of the front end portion of the free end of the cantilever 2 so as to face the sample S. The back surface of the front end portion is configured to reflect light. The front end portion of the cantilever 2 is displaced in the Z-axis direction due to a physical quantity (e.g., atomic force) acting between the probe 3 and the sample S.

[0030] An optical system 1 for detecting the deflection of the cantilever 2 (i.e., the displacement of the tip) is located above the cantilever 2 in the Z-axis direction. When measuring a sample S, the optical system 1 irradiates the back surface (reflective surface) of the cantilever 2 with laser light and detects the laser light reflected by the reflective surface. Specifically, the optical system 1 includes a laser light source 6, a beam splitter 5, a reflective mirror 7, and a photodetector 8.

[0031] The laser light source 6 includes a laser oscillator for emitting laser light. The photodetector 8 includes a photodiode for detecting the incident laser light. Laser light LA ​​emitted from the laser light source 6 is reflected by the beam splitter 5 and then irradiates the back surface (reflection surface) of the cantilever 2. The laser light reflected by the back surface of the cantilever 2 is then reflected by the reflective mirror 7 and enters the photodetector 8.

[0032] The photodetector 8 has a light-receiving surface divided into multiple (e.g., two) sections in the Z-axis direction (displacement direction) of the cantilever 2. Alternatively, the photodetector 8 has a light-receiving surface divided into four sections in the Z-axis and Y-axis directions. When the tip of the cantilever 2 displaces in the Z-axis direction, the ratio of the amount of light irradiated on the multiple light-receiving surfaces changes. Therefore, the deflection (displacement) of the cantilever 2 can be detected based on the multiple amounts of light received on these multiple light-receiving surfaces.

[0033] The feedback signal generator 22 calculates the deflection of the cantilever 2 by performing computational processing on the detection signal provided by the photodetector 8. The feedback signal generator 22 controls the Z-direction position of the sample S so that the atomic force between the probe 3 and the sample S remains constant. This control is hereinafter referred to as "feedback control." Feedback control corresponds to the "first control" of the present disclosure. Specifically, the feedback signal generator 22 calculates the deviation Sd between the calculated deflection of the cantilever 2 and the target value, and calculates the control variable for driving the Z scanner 12z so that the deviation Sd becomes zero. The feedback signal generator 22 calculates the voltage value Vz for displacing the Z scanner 12z in accordance with the control variable. The feedback signal generator 22 outputs a voltage signal representing the voltage value Vz to the Z-direction drive unit 18. The Z-direction drive unit 18 applies the voltage value Vz to the Z scanner 12z. Thus, the Z-direction drive unit 18 receives the voltage value input from the feedback signal generator 22 and applies a voltage based on the voltage value to the Z scanner 12z.

[0034] The information processing device 20 calculates the voltage value Vx in the X-axis direction and the voltage value Vy in the Y-axis direction of the XY-direction drive unit 16 so that the sample stage 14 moves relative to the probe 3 in the X-axis and Y-axis directions according to pre-set scanning conditions, and outputs the calculated voltage values ​​to the XY-direction drive unit 16. The XY-direction drive unit 16 applies the voltage values ​​Vx and Vy to the XY scanner 12xy.

[0035] The coarse motion mechanism 13 moves the sample stage 14 in the X-axis, Y-axis, and Z-axis directions. Furthermore, the first movement range of the sample stage 14 in the X-axis, Y-axis, and Z-axis directions, which is achieved by the fine motion mechanism 12, is smaller than the second movement range of the sample stage 14 in the coarse motion mechanism 13. Furthermore, due to reasons described below, the SPM 100 may not be able to properly measure the sample S. In such cases, the coarse motion mechanism 13 executes a retraction process under the control of the information processing device 20. The retraction process increases the distance between the probe 3 and the sample stage 14. The coarse motion mechanism 13 is driven by the information processing device 20.

[0036] The information processing device 20 mainly controls the operation of the measuring device 10. The measurement data indicating the feedback amount in the Z-axis direction (the applied voltage Vz and the deviation Sd applied to the Z scanner 12z) are sent from the Z-direction driving unit 18 to the information processing device 20. The measurement data are sent for each measurement point, which is a measurement point in the Y-axis direction of the sample S (refer to Figure 3) is determined at prescribed intervals on the scanning range. The information processing device 20 stores the measurement data. The information processing device 20 calculates the displacement of the sample S in the Z-axis direction according to the voltage Vz based on the pre-stored relevant information representing the relationship between the voltage Vz and the displacement of the sample S (sample stage 14) corresponding thereto in the Z-axis direction. The calculated displacement is a value reflecting the value representing the position of the sample S in the Z-axis direction (hereinafter also referred to as the "Z value"). The information processing device 20 creates two-dimensional or three-dimensional measurement data representing the shape of the surface of the sample S by calculating the displacement of the sample S in the Z-axis direction for each position in the X-axis and Y-axis directions within the scanning range. The information processing device 20 displays information such as the shape of the surface of the sample S on the display device 30 based on the measurement data.

[0037] The image data generated by the information processing device 20 includes a value (Z value) indicating the position in the Z-axis direction at each position on the XY plane. Furthermore, the Z value corresponds to the height of the surface at each position on the sample stage 14. Specifically, the Z value at the position where the sample S is located corresponds to the height including the sample S. The information processing device 20 displays the generated image data on the display device 30. Furthermore, the user inputs various information through the input device 40.

[0038] [Hardware Structure of Information Processing Device]

[0039] Figure 2 2 is a diagram showing an example of the hardware configuration of the information processing device 20. Figure 2 The information processing device 20 includes a CPU (Central Processing Unit) 160, a ROM (Read Only Memory) 162, a RAM (Random Access Memory) 164, an HDD (Hard Disk Drive) 166, a communication interface 168, a display interface 170, and an input interface 172 as its main components. These components are interconnected via a data bus. Furthermore, at least a portion of the hardware structure of the information processing device 20 may be located within the measuring device 10. Alternatively, the information processing device 20 may be configured separately from the scanning probe microscope 100 and configured to perform bidirectional communication with the scanning probe microscope 100.

[0040] The communication I / F 168 is an interface for communicating with the measurement device 10. The display I / F 170 is an interface for communicating with the display device 30. The input I / F 172 is an interface for communicating with the input device 40.

[0041] ROM 162 stores programs executed by CPU 160. RAM 164 can temporarily store data generated by CPU 160 executing programs and data input via communication I / F 168. RAM 164 can function as a temporary data storage area used as a work area. HDD 166 is a nonvolatile storage device. Instead of HDD 166, a semiconductor storage device such as flash memory can be used.

[0042] The program stored in ROM 162 may also be stored in a storage medium and circulated as a program product. Alternatively, the program may be provided by an information provider as a product program that can be downloaded via the Internet, etc. The information processing device 20 reads the program provided from the storage medium or the Internet, etc. The information processing device 20 stores the read program in a predetermined storage area (e.g., ROM 162). The CPU 160 can execute the image data acquisition process described later by executing the program.

[0043] The display device 30 can display a setting screen for setting image data acquisition conditions. In addition, during the image data acquisition process, the display device 30 can display image data generated by the information processing device 20 and data obtained by processing the image data.

[0044] The input device 40 receives input from a user (e.g., an analyst) including instructions to the information processing device 20. The input device 40 includes a keyboard, a mouse, and a touch panel integrally formed with the display screen of the display device 30, and receives image acquisition conditions and the like.

[0045] [Measurement range of sample S]

[0046] The user can input the measurement range of the sample S through the input device 40 . Figure 3 is a diagram showing an example of the measurement range R1. Figure 3 In the example shown in FIG, the measurement range R1 is set to a rectangular shape. Figure 3 As shown in FIG. 1 , the information processing device 20 moves the probe 3 relatively in a reciprocating manner along the measurement path L (the path of the first row) in the Y-axis direction of the sample S. Figure 3In the example of , the positive direction of the Y-axis corresponds to the "first direction" of the present disclosure, and the negative direction of the Y-axis corresponds to the "second direction" of the present disclosure. When the reciprocating movement of the probe 3 in the measurement path L ends, the probe 3 moves relative to the X-axis by a predetermined amount. Then, the probe 3 moves relative to each other again in a reciprocating manner in the next measurement path (the path of the second row). In this way, the probe 3 moves back and forth on all rows within the measurement range R1. In addition, as a modified example, the probe 3 can also move back and forth in the X-axis direction.

[0047] [Processing by the Information Processing Device]

[0048] Figure 4 : is a functional block diagram of the information processing device 20. The information processing device 20 has an input unit 102, a processing unit 104, a driving unit 106 and a storage unit 108. The measurement data (applied voltage Vz and deviation Sd) from the Z-direction driving unit 18 is input to the input unit 102. The measurement data is output to the processing unit 104. The processing unit 104 produces measurement data by calculating the displacement of the sample S in the Z-axis direction. Here, the data produced by the processing unit 104 when the probe 3 moves relative to each other in the above-mentioned first direction is referred to as "first measurement data". The first measurement data is the measurement data in the outward journey. In addition, the data produced by the processing unit 104 when the probe 3 moves relative to each other in the above-mentioned second direction is referred to as "second measurement data". The second measurement data is the measurement data in the return journey. In this way, the processing unit 104 produces the first measurement data and the second measurement data.

[0049] Furthermore, the processing unit 104 determines whether the deviation Sd is 0. During the measurement of the sample S, under normal conditions, the deviation Sd is set to 0 by executing the above-described feedback control. However, the deviation Sd may not be 0 due to the following reasons. These reasons include the first and second reasons.

[0050] The first reason is that the sample S has excessively large concave and convex parts, which will be described later. Excessively large concave and convex parts refer to excessively high convex parts and excessively deep concave parts. Excessively high convex parts are convex parts with a height in the Z-axis direction that is longer than the above-mentioned first moving range (the moving range of the sample stage 14 moved by the micro-motion mechanism 12). In addition, excessively deep concave parts are concave parts with a depth in the Z-axis direction that is longer than the above-mentioned first moving range. Here, the first moving range of the sample stage 14 moved by the micro-motion mechanism 12 is several μm to several tens of μm.

[0051] The second cause is thermal drift. Thermal drift occurs when the SPM 100 measures the sample S due to heat generated by the SPM 100 or the sample S. Thermal drift of the entire SPM 100 apparatus can cause unexpected changes in the relative position of the probe 3 and the sample S.

[0052] Unexpected changes in the relative position of probe 3 and sample S may occur over time, with probe 3 approaching sample S or moving away from sample S. For example, if thermal drift occurs in the direction of probe 3 approaching sample S, the deviation Sd may not reach zero even when Z scanner 12z is fully retracted while measurement of sample S continues. Conversely, if thermal drift occurs in the direction of probe 3 moving away from sample S, the deviation Sd may not reach zero even when Z scanner 12z is fully extended. In other words, the voltage applied to Z scanner 12z by Z-direction drive unit 18 reaches a maximum value Vmax or a minimum value Vmin due to thermal drift, and thus, despite the aforementioned feedback control, the deviation Sd does not reach zero (the atomic force is not constant). This state is referred to as "a state in which the influence of thermal drift beyond the operating range of micro-motion mechanism 12 occurs."

[0053] Hereinafter, the "thermal drift that causes the probe 3 and the sample S to approach each other over time" will also be referred to as the "first thermal drift." Furthermore, the "thermal drift that causes the probe 3 and the sample S to move away from each other over time" will also be referred to as the "second thermal drift." Furthermore, if thermal drift occurs, the type of thermal drift will not change midway. For example, if the first thermal drift occurs, the second thermal drift will not occur midway. Furthermore, if the second thermal drift occurs, the first thermal drift will not occur midway.

[0054] Next, a method for determining the cause type (whether it is the first cause or the second cause) will be described. If the processing unit 104 determines that the deviation Sd is not zero, it retrieves the measurement data stored in the storage unit 108 (previously acquired measurement data). For example, the processing unit 104 retrieves the most recently stored (most recently acquired) N measurement data. N is an integer greater than or equal to 1. Furthermore, each of the N measurement data includes the first measurement data and the second measurement data. The processing unit 104 then determines the cause type based on this measurement data.

[0055] Figure 5 This is an example of past measurement data. Figure 5 (A)~ Figure 5 In (C), the horizontal axis represents time t, and the vertical axis represents the height of the sample S measured by the SPM 10. Figure 5 In the figure, the measurement data of the outbound trip and the measurement data of the return trip are shown. The start time of the outbound trip measurement is set to "t0", the reversal time from the outbound trip to the return trip is set to "t1", and the end time of the return trip measurement is set to "t2". Figure 5In the example, for convenience, when reversing from the outbound trip to the return trip, the end time of the outbound trip measurement and the start time of the return trip measurement are the same, but sometimes the end time of the outbound trip measurement and the start time of the return trip measurement are different.

[0056] The processing unit 104 converts the measurement data from the return trip into inverse data (third measurement data) obtained by reversing the time series of the measurement data from the return trip. The processing unit 104 then calculates the degree of consistency between the measurement data from the outbound trip (first measurement data) and the inverse data corresponding to the return trip. The degree of consistency is a value that indicates the degree of consistency between the measurement data from the outbound trip and the inverse data. The degree of consistency is calculated, for example, based on the average or standard deviation of the differences between the values ​​represented by the measurement data at the same location on the sample S, between the measurement data from the outbound trip and the inverse data.

[0057] Figure 5 (A) is a diagram for explaining the reason why there is no thermal drift but there are too large concave and convex parts (i.e., the first reason). Figure 5 As shown in (A), the measurement data during the outbound measurement period is consistent with the inverse data (the degree of consistency is above the threshold). Therefore, the processing unit 104 obtains the value when the deviation Sd is not 0. Figure 5 In the case of the past measurement data shown in (A), it is determined to be the first cause.

[0058] Figure 5 (B) shows a case where a thermal drift (first thermal drift) occurs that acts to bring the probe 3 and the sample S closer. Figure 5 In (B), the measurement data of the return path is data indicating that the probe 3 and the sample S are close to each other due to the influence of the first thermal drift.

[0059] Figure 5 (C) shows a case where a thermal drift (second thermal drift) occurs that acts to move the probe 3 away from the sample S. Figure 5 In (C), the return measurement data is data indicating that the probe 3 and the sample S are separated by the influence of the second thermal drift. Figure 5 (B) and Figure 5 In the return path of (C), the dotted line indicates the waveform (normal waveform) when no thermal drift occurs.

[0060] also, Figure 5 For example, depending on the structure of the SPM 100, sometimes the measurement data is obtained when the first thermal drift occurs. Figure 5 The measurement data of (C) is obtained when the second thermal drift occurs. Figure 5 (B) The measurement data.

[0061] like Figure 5 (B) and Figure 5As shown in (C), the measurement data during the outbound measurement period is inconsistent with the inverse data (the consistency is less than the threshold). Therefore, the processing unit 104 obtains the error Sd when the deviation Sd is not 0. Figure 5 In the case of the past measurement data shown in (B), the second cause (the occurrence of the first thermal drift) is determined. In addition, when the deviation Sd is not 0, the processing unit 104 obtains Figure 5 In the case of the past measurement data shown in (C), the second cause (occurrence of the second thermal drift) is identified.

[0062] Furthermore, when the processing unit 104 determines the type of cause, it causes the storage unit 108 to store a flag (cause information) that identifies the type of cause. If the processing unit 104 determines the first cause, it causes the storage unit 108 to store a concave-convex portion flag. This concave-convex portion flag indicates that an excessively large concave-convex portion has been detected. If the processing unit 104 determines the second cause, it causes the storage unit 108 to store a thermal drift flag. This thermal drift flag indicates that thermal drift has been detected. Furthermore, when the processing unit 104 determines the first or second cause, it transmits a cause signal indicating the determined cause to the measuring device 10. The measuring device 10 receives the cause signal and can thereby determine the cause.

[0063] Furthermore, if the sample S has excessively large uneven portions as the first factor, the SPM 100 may not only be unable to properly measure the sample S, but also, if the measurement is continued, at least one of the sample S and the probe 3 may be damaged due to contact between the sample S and the probe 3. Therefore, the SPM 100 of this embodiment executes a second control for eliminating the influence of the first factor, and then continues the measurement after the second control.

[0064] Figure 6 is a diagram showing the second control for eliminating the influence of the first cause. Figure 6 In FIG, the sample S and the measurement range R1 set by the user are shown. Figure 6 As shown in (A) of FIG. 1 , the deviation Sd does not become 0 at part α (there is a special convex portion). In this case, the driving unit 106 drives the coarse motion mechanism 13 to perform a retraction process (a process of increasing the distance between the probe 3 and the sample stage 14 (sample S)). Thus, the SPM 100 can prevent the collision between the probe 3 and the sample S. Moreover, the measuring device 10 sets the voltage applied from the Z-direction driving unit 18 to the Z scanner 12z to zero. This is because there is a high possibility that the Z scanner 12z will completely shrink or completely expand in order to follow the shape of the excessively large concave and convex portion. And, as Figure 6As shown in (B), the processing unit 104 changes the measurement range from measurement range R1 to the new measurement range R2. The driving unit 106 drives the coarse motion mechanism 13 to move the sample stage 14 in a manner that enables measurement of the new measurement range R2. Then, the measuring device 10 resumes the measurement of the sample S within the measurement range R2. Since the voltage applied from the Z-direction driving unit 18 to the Z scanner is set to zero, the sample stage 14 is driven to the initial position. Therefore, the SPM 100 can reduce the collision between the probe 3 and the sample stage 14, and can measure the measurement range R2 with a margin within the extension and retraction range of the Z scanner 12z.

[0065] Here, the measurement range R2 is a range excluding part α, that is, a measurement range excluding part α where the atomic force is not fixed, and is preferably set to the same area as the area of ​​the measurement range R1. More specifically, the measurement range R2 is a range adjacent to part α. "Adjacent to part α" can mean "part α exists on the frame forming the measurement range R2." In addition, "adjacent to part α" can also mean "a predetermined distance away from the frame forming the measurement range R2." In addition, the information processing device 20 stores the XY coordinates of part α where the first cause occurred. Then, the information processing device 20 newly sets the measurement range R2 based on the XY coordinates of part α.

[0066] If the first cause recurs within the new measurement range R2, a new measurement range is set that excludes the portion α where the first cause recurs. In this manner, the SPM 100 repeatedly reconfigures the measurement range until measurement within the measurement range is completed without the first cause recurring. Furthermore, if, despite repeated reconfigurations of the measurement range, a measurement range that does not generate the first cause cannot be set for a sample S, the SPM 100 determines that measurement cannot be performed on that sample S and terminates the measurement process. Consequently, the information processing device 20 issues a notification indicating that the measurement cannot be performed.

[0067] Furthermore, when thermal drift, which is the second cause, occurs, the SPM 100 cannot appropriately measure the sample S. Therefore, the SPM 100 of this embodiment executes the second control for reducing the influence of the second cause, and continues the measurement after the second control.

[0068] Assume that during the measurement of sample S, deviation Sd does not reach zero (due to the influence of thermal drift exceeding the operating range of the fine motion mechanism 12). In this case, the drive unit 106 needs to drive the coarse motion mechanism 13 to perform a retraction process (a process that increases the distance between the probe 3 and the sample stage 14 (sample S)). The second control for eliminating the first and second causes includes this retraction process. This prevents collision between the probe 3 and the sample S. The measurement device 10 then sets the applied voltage to the Z scanner 12z to zero. As described above, in the state where "the influence of thermal drift exceeding the operating range of the fine motion mechanism 12 occurs," the voltage applied to the Z scanner 12z by the Z-direction drive unit 18 reaches the maximum value Vmax or the minimum value Vmin, so this voltage is adjusted to zero. The second control for eliminating the first and second causes includes the process of setting the applied voltage to zero. Furthermore, the drive unit 106 drives the coarse motion mechanism 13 to bring the probe 3 and sample S closer together again, and measurement of the sample S resumes within the measurement range R1. Since the voltage applied from the Z-direction drive unit 18 to the Z scanner is set to 0, the Z scanner 12 z can expand and contract again.

[0069] [SPM operation method]

[0070] Figure 7 This is a flowchart for explaining the operation method of the SPM 100. Figure 7 processing.

[0071] In step S2, the SPM 100 acquires the deviation Sd. Then, in step S4, the SPM 100 drives the Z scanner 12z by executing feedback control so that Sd = 0. Then, in step S5, the SPM 100 determines whether Sd = 0. If Sd = 0, in step S21, the SPM 100 causes the storage unit 108 to store the measurement data obtained when Sd = 0 was determined. Then, in step S22, the SPM 100 determines whether the measurement of the sample S has been completed. If the determination in S22 is "yes," the process ends. On the other hand, if the determination in step S22 is "no," the process returns to step S2.

[0072] If the determination in step S5 is "No," the SPM 100 temporarily stops the measurement in step S6. Next, in step S7, the SPM 100 drives the coarse motion mechanism 13 to retract the sample stage 14 from the cantilever 2. Then, in step S8, the SPM 100 resets the voltage applied by the Z-direction drive unit 18 to the Z scanner 12 to zero. Furthermore, in step S9, the SPM 100 determines the reason why Sd = 0 has not been achieved.

[0073] Figure 8 1 is a diagram for explaining the cause determination process of step S9. In step S72, the SPM 100 determines whether the measurement data is stored in the storage unit 108. Here, the measurement data is Figure 7 The SPM 100 then checks the measurement data for the sample S after the start of the processing. If no measurement data exists (for example, if the measurement of the first row has not yet been completed), the SPM 100 cannot determine the cause. Therefore, if the measurement data is not stored in the storage unit 108 in step S72 ("No" in step S72), the SPM 100 stops the measurement in step S82 and then ends the processing. Alternatively, the SPM 100 may notify the user that the processing has ended.

[0074] On the other hand, if the result of the judgment in step S72 is "yes", the process proceeds to step S74. In step S74, the SPM 100 generates the above-mentioned inverse data. Then, in step S76, it is judged whether the consistency between the outbound data and the generated inverse data is above the threshold value (refer to Figure 5 (Note: The following table contains the instructions for use with .

[0075] If the judgment is "yes" in step S76 (i.e. Figure 5 In the case of (A), in step S78, the SPM 100 detects an excessively large concave-convex portion (determining the first cause). On the other hand, in the case of "No" in step S76 (i.e. Figure 5 (B) or Figure 5 In the case of (C), in step S80, the SPM 100 detects thermal drift (determines the second cause).

[0076] Return instructions to Figure 7 When the process of step S9 is completed, the SPM 100 determines the determined cause in step S10. If the cause is excessive unevenness, the process proceeds to step S11, and if the cause is thermal drift, the process proceeds to step S16.

[0077] In step S11, the SPM 100 stores the concave-convex portion flag in a predetermined storage area (eg, Figure 2 Next, in step S12, the SPM 100 sets a new measurement range R2 (see FIG. 1 ) excluding the portion with excessive unevenness (that is, the portion determined not to have the deviation Sd=0 in step S5). Figure 6 ). Next, in step S14, the SPM 100 restarts the measurement of the sample S within the new measurement range R2, and the process returns to step S2.

[0078] In step S16, the SPM 100 stores the thermal drift flag. Next, in step S20, the SPM 100 drives the coarse motion mechanism 13 again to bring the probe 3 and the sample stage 14 (sample S) closer together, restarting measurement of the sample S within the measurement range R1, and the process returns to step S2.

[0079] In conventional SPM measurements of samples, there are cases where the atomic force does not become constant despite the aforementioned feedback control. This situation occurs, for example, when a sample has a convex portion that is too large for the SPM to measure. Continuing to measure a sample with such a convex portion can result in inaccurate measurement results.

[0080] Therefore, if Sd = 0 is not reached (if it is determined as "No" in step S5), the SPM 100 stops the measurement in step S6. Therefore, the SPM 100 can reduce the occurrence of inaccurate measurement results.

[0081] Furthermore, if the SPM remains in a state where the sample measurement is stopped, there may be a problem in that the completion time of the sample measurement is delayed.

[0082] Furthermore, for example, the SPM 100 may sometimes perform a measurement that requires a long time. Examples of such long measurements include measurements at high pixel counts, measurements at slow scanning speeds, and measurements of multiple samples. In such long-time measurements, the user may be located far away from the SPM 100. In such cases, there is a concern that if the user unexpectedly stops the measurement of a sample, a long time may elapse without the user noticing the stoppage. Furthermore, the measurement may need to be restarted, increasing the burden on the user.

[0083] On the other hand, when the atomic force is not constant, the SPM 100 stops the measurement of the sample S and then executes the second control. After executing the second control, the measurement of the sample is restarted (see FIG. 1 ). Figure 7 Step S14 and step S20). In addition, the second control is a control for reducing the influence caused by the cause. In the present embodiment, the second control is, for example, step S7 and step S8. Then, after executing the second control, the SPM 100 restarts the measurement of the sample (step S14 and step S20). Therefore, the SPM 100 can restart the measurement of the sample S after eliminating the cause of not becoming Sd=0. Thus, for the user, the occurrence of delays in the sample measurement can be reduced. In addition, the user does not need to operate the SPM 100 again to measure the sample S, and as a result, the burden on the user can be reduced.

[0084] Furthermore, the second control includes a retraction process (step S7 ) of the sample stage 14 , thereby reducing collisions between the probe 3 and the sample stage 14 .

[0085] Furthermore, the second control includes setting the applied voltage to the Z scanner 12z to zero. Consequently, the sample stage 14 is driven to its initial position. This reduces collisions between the probe 3 and the sample stage 14, and allows the SPM 100 to measure the measurement range R2 with a margin within the extension and retraction range of the Z scanner 12z.

[0086] In addition, the SPM 100 identifies the cause based on the past first measurement data and the second measurement data (see Figure 8 ). Therefore, the SPM 100 can determine the cause of the atomic force not becoming fixed.

[0087] Furthermore, if the degree of agreement between the forward and reverse data exceeds the threshold, the SPM 100 stores the concave-convex portion flag and executes the control of step S12 as a second control. Step S12 sets the measurement range of the sample S to a range excluding portions where the atomic force is not fixed. Thus, by setting the measurement range R1 of the sample S to a measurement range R2 excluding the portion α, the SPM 100 can measure portions of the sample S excluding the specific convex portion.

[0088] In addition, if Figure 6 As shown, the newly set measurement range R2 is a range adjacent to the portion α where the special convex portion exists (a portion where the deviation Sd does not become 0 despite feedback control). Therefore, the amount of movement in the XY plane when changing the measurement range can be minimized.

[0089] In addition, when the SPM 100 does not acquire the first measurement data and the second measurement data (in Figure 8 If "No" is determined in step S72, the measurement of the sample is stopped (step S82). Therefore, it is possible to prevent the measurement of the sample S from being continued in a state where the reason why Sd is not 0 cannot be determined.

[0090] [Other embodiments]

[0091] (1) The information processing device 20 may also perform a notification based on the identified cause (the type of the stored flag). For example, when the first cause is identified (when the measurement range R1 is set to the measurement range R2), the display device 30 may be used to notify the user. Figure 9 An example of a notification text displayed in the display area 30A of the display device 30 is shown. Figure 9In the example shown, a notification text 140 is displayed stating, "A convex or concave portion cannot be measured, so the measurement range has been changed." This notification is issued at a predetermined time after the occurrence of the first cause. This predetermined time is, for example, when the measurement of sample S within measurement range R2 is completed. Thus, the SPM 100 allows the user to recognize the presence of a convex or concave portion within the measurement range that cannot be measured and that the measurement range has been changed.

[0092] Furthermore, the information processing device 20 may notify the user using the display device 30 when the second cause occurs. Figure 10 An example of notification text displayed in the display area 30A of the display device 30 is shown. Figure 10 The notification text 150 is a text such as “Thermal drift has occurred.” With such a notification, the SPM 100 can make the user recognize that thermal drift has occurred.

[0093] (2) Figure 6 , the following structure is described: when a special convex portion or a special concave portion of the sample S is detected, the SPM 100 automatically changes the measurement range. However, there are cases where the user does not want to change the measurement range in this way. In view of this, the SPM 100 can also adopt a structure in which the user can select an automatic measurement mode or a stop mode. The automatic measurement mode is a mode in which the measurement of the sample S is restarted after the measurement of the sample S is stopped. The stop mode is a mode in which the measurement of the sample S is not restarted after the measurement of the sample S is stopped. The automatic measurement mode corresponds to the "first mode" of the present disclosure, and the stop mode corresponds to the "second mode" of the present disclosure.

[0094] Figure 11 This is an example of a mode selection screen. This selection screen is displayed in the display area 30A of the display device 30. This selection screen includes a text 190 reading "Please select a mode," an option 192 for the automatic measurement mode, and an option 194 for the stop mode.

[0095] The user can set the mode by checking the box of the desired option. The user selects the box using, for example, input device 40. SPM 100 receives input from the user selecting a mode and sets the selected mode. This allows the user to select either the stop mode or the automatic measurement mode, thereby improving user convenience.

[0096] (3) Figure 7, a configuration is described in which, when thermal drift occurs, the voltage applied to the Z scanner 12z is reset to 0 in step S8, and then the measurement is immediately restarted in step S20. However, if the measurement is immediately restarted, the influence of the thermal drift of the entire SPM 100 may remain, and the relative position of the probe 3 and the sample S may be unexpectedly changed due to the influence of thermal drift beyond the operating range of the fine motion mechanism 12.

[0097] Therefore, a waiting time may be provided to reduce or eliminate thermal drift of the entire SPM 100 before resuming measurement of the sample S. In this manner, the second control when thermal drift occurs includes stopping measurement of the sample S during the entire waiting time.

[0098] In this modification, a method for calculating the standby time is described. Generally speaking, when thermal drift occurs, the amount of thermal drift (the degree of influence of thermal drift) decreases as time passes from the occurrence of the thermal drift (see Figure 12 The SPM 100 of this modification calculates (or estimates) the standby time based on this phenomenon.

[0099] Figure 12 is a diagram for explaining a method for predicting the waiting time. Figure 12 1 , the thermal drift amount M1 at time t11 , the thermal drift amount M2 at time t12 , a mark A1 , and a mark A2 are shown, and a curve A of a function representing the relationship between the standby time and the thermal drift is shown.

[0100] The information processing device 20 creates a function curve A based on the thermal drift amounts M1 and M2 and the elapsed time T0. More specifically, the information processing device 20 calculates the difference ΔM between the thermal drift amounts M1 and M2. The information processing device 20 then divides the difference ΔM by the elapsed time T0 to calculate the rate of change of the thermal drift amount. The function curve A is then created based on this rate of change. The function creation formula is stored in, for example, the storage unit 108.

[0101] The information processing device 20 then calculates the time T1 until the thermal drift amount reaches the minimum value M0 (time t13 ) as the waiting time based on the curve A. The start time of the waiting time T1 is, for example, the time when the calculation of the waiting time T1 is completed.

[0102] Figure 13 This is a diagram for explaining the thermal drift amount M1 and the thermal drift amount M2. The information processing device 20 uses the past measurement data of two or more measurement paths (two or more lines). Figure 13 As shown in (A) of FIG. 1 , the information processing device 20 performs the first measurement path of the sample S (in Figure 13In the example of the first row, the first measurement data (measurement data of the outbound trip) and the second measurement data (measurement data of the return trip) are used to calculate the first measurement difference value M1a. Specifically, the information processing device 20 calculates the inverse data of the outbound trip (data obtained by reversing the time series). Figure 13 In (A), the outbound reverse data is represented by a dotted line. The information processing device 20 then calculates a first measured differential value M1a, which is the difference between this inverse data and the return data. The first measured differential value M1a corresponds to the amount of thermal drift. The greater the thermal drift, the greater the measured differential value. Furthermore, the information processing device 20 calculates the thermal drift amount M1 by multiplying the first measured differential value M1a by a predetermined coefficient C. The coefficient C is a real number and can be set to 1.

[0103] In addition, if Figure 13 As shown in (B), the information processing device 20 performs the second measurement path of the sample S (in Figure 13 In the example of the second row, the information processing device 20 calculates the second measurement difference value M2a based on the first measurement data (measurement data of the outbound trip) and the second measurement data (measurement data of the return trip). Specifically, the information processing device 20 calculates the inverse data of the outbound trip (data obtained by reversing the time series). Figure 13 In (B), the outbound reverse data is represented by a dotted line. The information processing device 20 then calculates a second measured differential value M2a, which is the difference between the inverse data and the return data. The second measured differential value M2a corresponds to the amount of thermal drift. Furthermore, as described above, generally speaking, when thermal drift occurs, the amount of thermal drift decreases over time from the time of occurrence. Therefore, the second measured differential value M2a is smaller than the first measured differential value M1a. Furthermore, the information processing device 20 calculates the amount of thermal drift M2 by multiplying the second measured differential value M2a by the aforementioned coefficient C.

[0104] Furthermore, the information processing device 20 obtains the value of the data when the relative reciprocating movement of the probe 3 in the first measurement path is completed ( Figure 12 From time t11 of the measurement to the end of the relative reciprocating movement of the probe in the second measurement path ( Figure 12 The information processing device 20 can obtain the elapsed time T0 based on the scanning speed of the probe 3 and the number of measured pixels. In addition, the information processing device 20 may also include a timer for measuring the elapsed time T0.

[0105] The information processing device 20 then creates a curve A based on the thermal drift amount M1 (calculated from the first measured differential value M1a), the thermal drift amount M2 (calculated from the second measured differential value M2a), and the elapsed time T0, and uses the curve A to calculate the waiting time T1.

[0106] Figure 14 This is a flowchart for explaining the operation method of the SPM of this modification. Figure 14 In the flowchart of Figure 7 Steps S17 and S18 are added between step S16 and step S20 in the flowchart of FIG.

[0107] When the processing of step S16 is completed, the SPM 100 calculates the waiting time T1 in step S17. Next, in step S18, the SPM 100 determines whether the waiting time T1 has elapsed. The SPM 100 performs the process of stopping the measurement of the sample S during the entire waiting time as the second control described above ("No" in step S18). Then, if the waiting time T1 has elapsed ("Yes" in step S18), the SPM 100 resumes the measurement of the sample S in step S20.

[0108] Figure 15 This is a flowchart of the standby time calculation process in step S17. In step S102, the SPM 100 calculates a first measurement difference value M1a based on first and second measurement data from a previous first measurement route. Next, in step S104, the SPM 100 calculates a second measurement difference value M2a based on first and second measurement data from a previous second measurement route.

[0109] Next, in step S106, the SPM 100 obtains the elapsed time T0. Then, the SPM 100 calculates the waiting time T1 by creating a curve A. In addition, in this modification, as shown in FIG. Figure 12 As shown, the waiting time T1 is calculated using data of two markers (marker A1 and marker A2 ), but the curve A may be calculated using data of three or more markers.

[0110] According to this modification, the SPM 100 can calculate the waiting time T1 corresponding to the amount of thermal drift that has occurred. Furthermore, the SPM 100 resumes measurement of the sample S after the waiting time T1 has elapsed, thereby enabling measurement of the sample S with reduced influence of thermal drift.

[0111] In this modified example, the SPM 100 calculates the standby time T1. However, the standby time T1 may be set to a predetermined time. For example, the predetermined time may be one hour. Alternatively, the standby time T1 may be user-configurable. Even with this configuration, the SPM 100 resumes measurement of the sample S after the standby time T1 has elapsed, thereby enabling measurement of the sample S with reduced influence from thermal drift.

[0112] [Way]

[0113] It should be understood by those skilled in the art that the above-described multiple exemplary embodiments are specific examples of the following aspects.

[0114] (Item 1) A scanning probe microscope according to one embodiment is used for measuring a sample and comprises: a sample stage for arranging the sample; a probe arranged so as to face the sample; a first drive mechanism for moving the probe relative to the surface of the sample by performing a first control so as to make a physical quantity acting between the probe and the sample constant; and a control device for stopping the measurement of the sample if the physical quantity does not become constant despite the execution of the first control.

[0115] According to such a configuration, even when the physical quantity acting between the probe and the sample is not constant, the measurement of the sample is stopped, thereby reducing the possibility of obtaining inaccurate measurement results.

[0116] (Item 2) In the scanning probe microscope described in Item 1, when the physical quantity is not constant, the control device executes the second control after stopping the measurement of the sample, and the control device resumes the measurement of the sample after executing the second control.

[0117] According to such a configuration, even when the physical quantity acting between the probe and the sample has not become constant, the measurement of the sample can be restarted.

[0118] (Item 3) The scanning probe microscope according to Item 2 further includes a second drive mechanism that performs a retraction process for increasing the distance between the probe and the sample stage, wherein the second control includes the retraction process.

[0119] According to such a configuration, when the physical quantity acting between the probe and the sample is not constant, the retraction process of increasing the distance between the probe and the sample stage is executed, thereby reducing collisions between the probe and the sample stage.

[0120] (Item 4) In the scanning probe microscope described in Item 2 or Item 3, the first driving mechanism performs the following processing: driving the sample stage according to the applied voltage, and driving the sample stage to the initial position when the applied voltage is zero, and the second control includes the processing of setting the voltage applied to the first driving mechanism to zero.

[0121] According to this configuration, when the physical quantity acting between the probe and the sample is not constant, the sample stage can be driven to the initial position. Therefore, when the measurement of the sample is resumed, the collision between the probe and the sample stage can be reduced.

[0122] (Item 5) In the scanning probe microscope described in any one of Items 2 to 4, the control device performs the following processing: the probe is moved back and forth relatively in a first direction and a second direction in the same measurement path of the sample to obtain measurement data of the sample, wherein the first direction and the second direction are orthogonal to the height direction of the sample, and the second direction is a direction opposite to the first direction, the first measurement data obtained by the movement of the probe in the first direction in the same measurement path and the second measurement data obtained by the movement of the probe in the second direction in the same measurement path are stored, and when the physical quantity is not fixed, the reason why the physical quantity is not fixed is determined based on the stored first measurement data and second measurement data, and reason information that can determine the determined reason is stored.

[0123] According to such a configuration, the cause information can be specified based on the first measurement data and the second measurement data.

[0124] (Item 6) In the scanning probe microscope described in Item 5, when the degree of consistency between first measurement data and data obtained by reversing the time series of second measurement data is greater than a threshold value, the control device performs control of setting the measurement range of the sample to a measurement range excluding a portion where the physical quantity is not fixed as a second control.

[0125] With this configuration, if the degree of agreement is above the threshold, there is a high probability that the sample contains convex or concave portions that cannot be measured by the scanning probe microscope. Since measurement cannot be performed within the measurement range that includes the convex or concave portions, proper measurement of the sample can be achieved by setting the measurement range to exclude the convex or concave portions.

[0126] (Item 7) In the scanning probe microscope described in Item 6, the measurement range is set to be a range adjacent to the site.

[0127] According to such a configuration, the driving amount of the first driving mechanism can be minimized when the range is changed.

[0128] (Item 8) In the scanning probe microscope described in any one of Items 5 to 7, when the degree of consistency between the first measurement data and the data obtained by reversing the time series of the second measurement data is less than a threshold value, the control device executes a process of stopping the measurement of the sample during the entire predetermined standby time as the second control.

[0129] According to such a configuration, the scanning probe microscope resumes the measurement of the sample after the standby time has elapsed, and thus the sample S can be measured with the influence of thermal drift reduced.

[0130] (Item 9) In the scanning probe microscope described in any one of Items 5 to 7, when the consistency between the first measurement data and the data obtained by reversing the time series of the second measurement data is less than a threshold value, the control device performs the following processing as the second control: calculating a first measurement differential value based on the first measurement data and the second measurement data on the first measurement path of the sample, calculating a second measurement differential value based on the first measurement data and the second measurement data on the second measurement path of the sample, obtaining the elapsed time from the end of the relative reciprocating movement of the probe in the first measurement path to the end of the relative reciprocating movement of the probe in the second measurement path, calculating a standby time based on the first measurement differential value, the second measurement differential value and the elapsed time, and stopping the measurement of the sample during the entire calculated standby time.

[0131] With this configuration, a waiting time corresponding to the amount of thermal drift can be calculated. Furthermore, the scanning probe microscope resumes measurement of the sample after the waiting time has elapsed, thereby enabling measurement of the sample S with reduced influence of thermal drift.

[0132] (Item 10) In the scanning probe microscope according to any one of Items 5 to 9, when the first measurement data and the second measurement data are not stored, the control device stops the measurement of the sample.

[0133] According to this configuration, if the first and second measurement data are not stored, for example, if one reciprocating movement is not completed, the cause cannot be determined. In this case, the sample measurement can be stopped, thereby ensuring safety.

[0134] (Item 11) In the scanning probe microscope according to any one of Items 5 to 10, the control device performs notification based on the cause information.

[0135] According to such a configuration, the user can recognize the content of the cause that has occurred.

[0136] (Item 12) In the scanning probe microscope described in any one of Items 2 to 11, the control device is capable of switching between the following modes according to user input: a first mode in which the measurement of the sample is stopped and then the measurement of the sample is restarted; and a second mode in which the measurement of the sample is not restarted after the measurement of the sample is stopped.

[0137] According to such a configuration, the user can select either the first mode of resuming the sample measurement after stopping the sample measurement or the second mode of not resuming the sample measurement after stopping the sample measurement.

[0138] (Item 13) Other control methods include a control method for a scanning probe microscope for measuring a sample, the scanning probe microscope comprising: a sample stage for configuring the sample; a probe configured to face the sample; and a first drive mechanism for moving the probe relative to the surface of the sample, the control method comprising: executing a first control for fixing a physical quantity acting between the probe and the sample; and stopping the measurement of the sample when the physical quantity does not become fixed despite the execution of the first control.

[0139] According to such a configuration, even when the physical quantity acting between the probe and the sample is not constant, the measurement of the sample is stopped, thereby reducing the possibility of obtaining inaccurate measurement results.

[0140] Furthermore, regarding the above-described embodiments and modifications, it is intended from the original application that the configurations described in the embodiments can be appropriately combined within a range that does not cause inconvenience or contradiction, including combinations not described in the specification.

[0141] While the embodiments of the present invention have been described, the embodiments disclosed herein are intended to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to include all modifications within the meaning and scope of the claims and equivalents.

Claims

1. A scanning probe microscope for measuring a sample, comprising: A sample table, used for placing the sample; a probe disposed to face the sample; a first driving mechanism that performs first control so as to keep a physical quantity acting between the probe and the sample constant, thereby relatively moving the probe along the surface of the sample; and a control device that stops measuring the sample when the physical quantity does not become constant despite executing the first control, The control device performs the following processing: The probe is moved back and forth relatively in a first direction and a second direction in the same measurement path of the sample to acquire measurement data of the sample, wherein: The first direction and the second direction are orthogonal to the height direction of the sample, and the second direction is a direction opposite to the first direction. When the physical quantity is not constant, if the degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is greater than a threshold value, cause information indicating why the sample has an excessively large concave portion or an excessively large convex portion is stored; When the physical quantity is not constant and the degree of coincidence is smaller than the threshold value, cause information indicating a cause of thermal drift of the scanning probe microscope is stored.

2. The scanning probe microscope according to claim 1, wherein If the physical quantity is not constant, the control device stops measuring the sample and then performs a second control. The control device resumes measurement of the sample after executing the second control.

3. The scanning probe microscope according to claim 2, wherein: The scanning probe microscope further includes a second drive mechanism that performs a retraction process to increase the distance between the probe and the sample stage. The second control includes the backoff process.

4. The scanning probe microscope according to claim 2 or 3, wherein: The first driving mechanism performs the following processing: The sample stage is driven according to the applied voltage, When the applied voltage is zero, the sample stage is driven to an initial position, and the second control includes a process of setting the voltage applied to the first drive mechanism to zero.

5. The scanning probe microscope according to any one of claims 1 to 3, wherein When the first measurement data and the second measurement data are not stored, the control device stops the measurement of the sample.

6. The scanning probe microscope according to any one of claims 1 to 3, wherein The control device performs notification based on the cause information.

7. The scanning probe microscope according to any one of claims 1 to 3, wherein The control device can switch the following modes according to the user's input: A first mode is to restart the measurement of the sample after stopping the measurement of the sample; and In the second mode, the measurement of the sample is stopped but not restarted.

8. A scanning probe microscope for measuring a sample, comprising: A sample table, used for placing the sample; a probe disposed to face the sample; a first driving mechanism that performs first control so as to keep a physical quantity acting between the probe and the sample constant, thereby relatively moving the probe along the surface of the sample; and a control device that stops measuring the sample when the physical quantity does not become constant despite executing the first control, The control device performs the following processing: The probe is moved back and forth relatively in a first direction and a second direction in the same measurement path of the sample to acquire measurement data of the sample, wherein: The first direction and the second direction are orthogonal to the height direction of the sample, and the second direction is a direction opposite to the first direction. When the physical quantity is not constant, When the degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is greater than a threshold value, a second control is executed in which the measurement range of the sample is set to a measurement range excluding a portion where the physical quantity is not constant. After the second control is executed, the measurement of the sample is restarted.

9. The scanning probe microscope according to claim 8, wherein The measurement range that is set is a range adjacent to the site.

10. The scanning probe microscope according to claim 8 or 9, wherein: When the first measurement data and the second measurement data are not stored, the control device stops the measurement of the sample.

11. The scanning probe microscope according to claim 8 or 9, wherein: The control device can switch the following modes according to the user's input: A first mode is to restart the measurement of the sample after stopping the measurement of the sample; and In the second mode, the measurement of the sample is stopped but not restarted.

12. A scanning probe microscope for measuring a sample, comprising: A sample table, used for placing the sample; a probe disposed to face the sample; a first driving mechanism that performs first control so as to keep a physical quantity acting between the probe and the sample constant, thereby relatively moving the probe along the surface of the sample; and a control device that stops measuring the sample when the physical quantity does not become constant despite executing the first control, The control device performs the following processing: The probe is moved back and forth relatively in a first direction and a second direction in the same measurement path of the sample to acquire measurement data of the sample, wherein: The first direction and the second direction are orthogonal to the height direction of the sample, and the second direction is a direction opposite to the first direction. When the physical quantity is not constant, and when the degree of consistency between first measurement data acquired by the movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by the movement of the probe in the second direction is less than a threshold value, a second control is executed to stop the measurement of the sample for the entire predetermined standby time. After the second control is executed, the measurement of the sample is restarted.

13. The scanning probe microscope according to claim 12, wherein: When the first measurement data and the second measurement data are not stored, the control device stops the measurement of the sample.

14. The scanning probe microscope according to claim 12 or 13, wherein: The control device can switch the following modes according to the user's input: A first mode is to restart the measurement of the sample after stopping the measurement of the sample; and In the second mode, the measurement of the sample is stopped but not restarted.

15. A scanning probe microscope for measuring a sample, comprising: A sample table, used for placing the sample; a probe disposed to face the sample; a first driving mechanism that performs first control so as to keep a physical quantity acting between the probe and the sample constant, thereby relatively moving the probe along the surface of the sample; and a control device that stops measuring the sample when the physical quantity does not become constant despite executing the first control, The control device performs the following processing: The probe is moved back and forth relatively in a first direction and a second direction in the same measurement path of the sample to acquire measurement data of the sample, wherein: The first direction and the second direction are orthogonal to the height direction of the sample, and the second direction is a direction opposite to the first direction. When the physical quantity is not constant, and when the degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is less than a threshold value, the following second control is performed: calculating a first measurement difference value based on the first measurement data and the second measurement data on the first measurement path of the sample, calculating a second measurement difference value based on the first measurement data and the second measurement data on a second measurement path of the sample, acquiring the elapsed time from the completion of the relative reciprocating movement of the probe in the first measurement path to the completion of the relative reciprocating movement of the probe in the second measurement path, calculating a waiting time based on the first measured difference value, the second measured difference value, and the elapsed time, Stop measuring the sample during the entire calculated waiting time. After the second control is executed, the measurement of the sample is restarted.

16. The scanning probe microscope according to claim 15, wherein When the first measurement data and the second measurement data are not stored, the control device stops the measurement of the sample.

17. The scanning probe microscope according to claim 15 or 16, wherein: The control device can switch the following modes according to the user's input: A first mode is to restart the measurement of the sample after stopping the measurement of the sample; and In the second mode, the measurement of the sample is stopped but not restarted.

18. A method for controlling a scanning probe microscope, the scanning probe microscope being used to measure a sample, the scanning probe microscope comprising: A sample table, used for placing the sample; a probe disposed to face the sample; as well as a first driving mechanism that moves the probe relatively along the surface of the sample, The control method includes: executing a first control to make a physical quantity acting between the probe and the sample constant; stopping the measurement of the sample when the physical quantity does not become constant despite the execution of the first control; Acquiring measurement data of the sample by relatively reciprocating the probe in a first direction and a second direction along the same measurement path of the sample, wherein the first direction and the second direction are orthogonal to a height direction of the sample, and the second direction is a direction opposite to the first direction; If the physical quantity is not constant, and if a degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is greater than a threshold value, storing cause information indicating a cause why the sample has an excessively large concave portion or an excessively large convex portion; and When the physical quantity is not constant and the degree of coincidence is smaller than the threshold value, cause information indicating a cause of thermal drift of the scanning probe microscope is stored.

19. A method for controlling a scanning probe microscope, the scanning probe microscope being used to measure a sample, the scanning probe microscope comprising: A sample table, used for placing the sample; a probe disposed to face the sample; as well as a first driving mechanism that moves the probe relatively along the surface of the sample, The control method includes: executing a first control to make a physical quantity acting between the probe and the sample constant; stopping the measurement of the sample when the physical quantity does not become constant despite the execution of the first control; Acquiring measurement data of the sample by relatively reciprocating the probe in a first direction and a second direction along the same measurement path of the sample, wherein the first direction and the second direction are orthogonal to a height direction of the sample, and the second direction is a direction opposite to the first direction; When the physical quantity is not constant, if a degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is greater than a threshold value, performing a second control of setting the measurement range of the sample to a measurement range excluding a portion where the physical quantity is not constant; and After the second control is executed, the measurement of the sample is restarted.

20. A method for controlling a scanning probe microscope, the scanning probe microscope being used to measure a sample, the scanning probe microscope comprising: A sample table, used for placing the sample; a probe disposed to face the sample; as well as a first driving mechanism that moves the probe relatively along the surface of the sample, The control method includes: executing a first control to make a physical quantity acting between the probe and the sample constant; stopping the measurement of the sample when the physical quantity does not become constant despite the execution of the first control; Acquiring measurement data of the sample by relatively reciprocating the probe in a first direction and a second direction along the same measurement path of the sample, wherein the first direction and the second direction are orthogonal to a height direction of the sample, and the second direction is a direction opposite to the first direction; When the physical quantity is not constant, if a degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is less than a threshold value, executing a second control for stopping measurement of the sample for the entire predetermined standby time; and After the second control is executed, the measurement of the sample is restarted.

21. A method for controlling a scanning probe microscope, the scanning probe microscope being used to measure a sample, the scanning probe microscope comprising: A sample table, used for placing the sample; a probe disposed to face the sample; as well as a first driving mechanism that moves the probe relatively along the surface of the sample, The control method includes: executing a first control to make a physical quantity acting between the probe and the sample constant; stopping the measurement of the sample when the physical quantity does not become constant despite the execution of the first control; Acquiring measurement data of the sample by relatively reciprocating the probe in a first direction and a second direction along the same measurement path of the sample, wherein the first direction and the second direction are orthogonal to a height direction of the sample, and the second direction is a direction opposite to the first direction; When the physical quantity is not constant, and when the degree of consistency between first measurement data acquired by movement of the probe in the first direction and data obtained by reversing the time series of second measurement data acquired by movement of the probe in the second direction is less than a threshold value, the following second control is performed: calculating a first measurement difference value based on the first measurement data and the second measurement data on the first measurement path of the sample, calculating a second measurement difference value based on the first measurement data and the second measurement data on a second measurement path of the sample, acquiring the elapsed time from the completion of the relative reciprocating movement of the probe in the first measurement path to the completion of the relative reciprocating movement of the probe in the second measurement path, calculating a waiting time based on the first measured difference value, the second measured difference value, and the elapsed time, Stop measuring the sample during the entire calculated waiting time. After the second control is executed, the measurement of the sample is restarted.

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