JPH08201403A - Scanning type prove microscope - Google Patents

Abstract

PURPOSE: To measure the surface information of a sample when the voltage applied across a piezoelectric body or scanning time reaches measuring point displacement information stored on an information table by performing measurement scanning after preliminary scanning so as to measure the surface information of the sample with high resolution and high accuracy without being affected by the environment nor lowering the scanning speed. CONSTITUTION: A microcomputer 23 incorporated with a timer 22 controls an XYZ cylindrical piezoelectric body 27 through a Z-control section 24, X- scanning D/A converter 25, and Y-scanning D/A converter 26. An X-displacement sensor 33 and Y-displacement sensor 34 housed in a barrel 32 at the lower end of the piezoelectric body 27 detect the moving amount of a sample stage 28 in a two-dimensional direction and send the moving amount to the microcomputer 23 through an X-displacement A/D converter 35 and Y-displacement A/D converter 36. The microcomputer 23 stores the X- and Y-voltages applied across the piezoelectric body 27 on an X-displacement information table 37 and Y- displacement information table 38 as the displacement information of measuring points X and Y.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning probe microscope, and more specifically, it detects the interaction between a sample and a probe when the sample surface is two-dimensionally scanned by the probe to acquire surface information of the sample. The present invention relates to a scanning probe microscope.

[0002]

2. Description of the Related Art A general scanning probe microscope (hereinafter referred to as S
(Referred to as PM) is configured as shown in FIGS. 11 and 12, for example. 11 and 12, the Z control unit 3 is connected to the microcomputer 2 to which the host computer 1 is connected, and the X scan D / A
The X feedback drive circuit 6 and the Y feedback drive circuit 7 are connected via the converter 4 and the Y scan D / A converter 5. Further, the sample 10 is placed on the sample table 9 provided on the XYZ driving piezoelectric body 8 to which the Z control unit 3, the X feedback driving circuit 6, and the Y feedback driving circuit 7 are connected. There is.

A probe displacement detector 11 is connected to the Z controller 3, and a cantilever (probe) is attached to the tip of the probe displacement detector 11.
12 are provided. The XYZ driving piezoelectric body 8 is used.
Is operated by an X displacement sensor 14 and a Y displacement sensor 15 provided in the mirror body 13.

In such a structure, the X-direction displacement (X-direction movement amount) and the Y-direction displacement (Y-direction movement amount) of the piezoelectric body 8, that is, the sample table 9, are detected by the X and Y displacement sensors 14 and 1.
Detected by 5. These displacement signals ds6 and ds
8 is input to one input terminal of each of the X, Y feedback drive circuits 6 and 7. In addition, the microcomputer 2
X scan data D3, Y scan data D
4 is an X scanning signal ds3 and a Y scanning signal ds4 converted by the X and Y scanning D / A converters 4 and 5, respectively.
It is input to the other input terminals of the Y feedback drive circuits 6 and 7.

Then, the X, Y feedback drive circuit 6
In and 7, the displacement signals ds6 and ds of the piezoelectric body 8
8 and the scanning signals ds3 and ds4 are feedback-controlled so as to maintain linearity. As a result, the distortion of the sample surface information image caused by the applied voltage to the piezoelectric body 8 and the hysteresis characteristic of the displacement as shown in FIG. 13 is eliminated, and a highly linear image is obtained in the host computer 1. To be

[0006]

However, in such a conventional scanning probe microscope, the displacement resolution of the piezoelectric body 8 is about 0.01 nm, and X, Y is higher than this resolution.
The displacement detection resolution of the displacement sensors 14 and 15 is inferior to several nm. Therefore, when the X, Y feedback drive circuits 6 and 7 operate, the X, Y displacement sensors 14, 15
This noise causes the piezoelectric body 8 to vibrate slightly and damage the tip of the cantilever 12 and the surface of the sample 10. In addition, the fact that the hysteresis curve differs depending on the external environment has also been an obstacle to noise reduction.

Further, when the surface information of the sample 10 is imaged, the resolution is lowered to the resolution of the X, Y displacement sensors 14, 15. Furthermore, X, Y
By providing the feedback drive circuits 6 and 7 and performing feedback control, the response becomes slower, which causes a problem that the scanning speed must be slowed down.

The present invention has been made in view of the above problems, and is not affected by the displacement of the piezoelectric body and the voltage hysteresis characteristic, does not decrease the scanning speed, and has high resolution and high linearity and high accuracy. An object is to provide a scanning probe microscope capable of measuring surface information.

[0009]

That is, the present invention provides a piezoelectric body for scanning a probe or a sample, a driving means for deforming the piezoelectric body in at least one of the XYZ directions, and at least one of the piezoelectric bodies in the XYZ directions. Displacement detection means for detecting displacement in the direction, information storage means for storing displacement information of the measurement point of the piezoelectric body at the point where sample surface information is to be measured, and during the preliminary scanning before measuring the sample surface information, the above information Table creating means for pre-storing the measurement point displacement information of the sample surface information in the storage means, and a measurement point based on the measurement point displacement information stored in the information storage means during measurement scanning for measuring the sample surface information. And a measuring means for measuring the sample surface information.

[0010]

In the scanning probe microscope of the present invention, preliminary scanning is performed, and the displacement is continuously detected by the displacement detecting means while voltage-driving the piezoelectric body at a resolution higher than the number of points at which sample surface information is measured. It is detected whether or not the displacement has reached the displacement of a preset measurement point. Each time the displacement reaches the measurement point, the piezoelectric body applied voltage or the scanning time is stored in the information table as the measurement point displacement information. After the completion of the preliminary scanning, measurement scanning is performed, and the sample surface information is measured and imaged when the piezoelectric applied voltage or the scanning time reaches the measurement point displacement information stored in the information table. By the above measurement, a highly linear image can be obtained without slowing down the scanning speed.

Further, when the information table is created, the table surface is created by interpolating the measurement point displacement information such as the voltage applied to the piezoelectric body or the scanning time, so that the sample surface information can be obtained with a resolution higher than the displacement resolution of the displacement detecting means. Can be measured. Therefore, an image with high resolution and high linearity can be obtained without slowing down the scanning speed.

Further, at the time of each line measurement scan, while the sample surface information is measured based on the measurement point displacement information stored in the information table, the information table created at the preliminary scan is created for the next line measurement scan. As a result, an image with high resolution and high linearity with less drift can be obtained without slowing down the scanning speed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of a scanning probe microscope according to the present invention.

In FIG. 1, the host computer 21
Is for displaying the unevenness of the sample 29 as an image, and is connected to a microcomputer 23 containing a timer 22. The host computer 23 includes a Z control unit 2
4, X scan D / A converter 25, Y scan D / A converter 26
Is connected.

Further, the sample stage 28 provided on the XYZ driving cylindrical piezoelectric body 27 to which the Z control section 24, the X scan D / A converter 25 and the Y scan D / A converter 26 are connected,
The sample 29 is placed. A probe displacement detection unit 30 is also connected to the Z control unit 24, and a cantilever (probe) 31 is provided at the tip thereof.

The lower end of the XYZ driving cylindrical piezoelectric body 12 is fixed to a mirror body 32, and the sample stand 28 is installed on the upper end thereof. Inside the mirror body 32, an X displacement sensor 3 for detecting the amount of movement of the sample table 28 in the two-dimensional direction.
3 and Y displacement sensors 34 are provided.

The microcomputer 23 includes an X displacement A / D converter 35 and a Y displacement A / D converter 36 which receive displacement signals from the X displacement sensor 33 and the Y displacement sensor 34, and a piezoelectric X applied voltage. Is connected as the measurement point X displacement information, and the Y displacement information table 38 for storing the piezoelectric body Y applied voltage as the measurement point Y displacement information is connected.

In such a structure, the probe displacement detecting section 30 has the cantilever 31 by the well-known optical lever method.
The displacement signal S1 is detected and the displacement signal S1 is output to the Z control unit 24. The Z control unit 24 performs feedback control so as to keep the displacement of the cantilever 31 constant, and controls the piezoelectric body 27 to Z.
The Z control signal S2 for expanding and contracting in the direction is output, and the Z control data D2, that is, the sample unevenness information, is sent to the microcomputer 2 in response to a request from the microcomputer 23.
Output to 3.

The host computer 21 stores the measurement data D1 transferred from the microcomputer 23,
Form an image. The X-scan D / A converter 25 converts the X-scan data D3 output from the microcomputer 23 into D / A.
It is A-converted and output to the piezoelectric body 27 as an X scanning signal S3. Similarly, the Y scan D / A converter 26 converts the Y scan data D4 output from the microcomputer 23 into D / A.
It is converted and output to the piezoelectric body 27 as the Y scanning signal S4.

In the X-displacement A / D converter 35, the X-displacement signal S6 detected by the X-displacement sensor 33 is A / D-converted in response to a request from the microcomputer 23, and is sent to the microcomputer 23 as X-displacement data D5. Output. Y
The displacement A / D converter 36 A / D converts the Y displacement signal S8 detected by the Y displacement sensor 34 in response to a request from the microcomputer 23, and outputs it as Y displacement data D6 to the microcomputer 23.

FIG. 2 is a diagram showing the positional relationship between the sample 29 and the tip of the cantilever 31 during preliminary scanning for creating a displacement information table and measuring scanning of the sample surface in the scanning probe microscope of the present invention. .

Next, with reference to the flow chart of FIG. 3 and the timing chart of FIG. 4, an X displacement information table creation sequence by X preliminary scanning will be described. In the example, the number of measurement points is 256.

First, the X target register in the flowchart will be described. The X target register is X displacement data corresponding to each measurement point, and is updated with X displacement data corresponding to the next measurement point each time displacement information (X applied voltage) at each measurement point is obtained. .

The X displacement measurement point number register counts the number of points at which the sample surface information should be measured during X scanning, and each time displacement information (X applied voltage) corresponding to the X displacement at each measurement point is obtained. Incremented from 0 to 256.

The X pre-scanning of the sample 29 is performed by the 2
The dimensional scanning is started in the state in which it is at the leading point of the first scanning line (the scanning origin in FIG. 2). Then, "0" is initialized to the X table pointer as shown in FIG. 5A (step S1). The X displacement value Δx0 corresponding to the X scanning position of the first measurement point is set in the X target register (step S2).

When the X scan data D3 is incremented, the voltage of the X scan signal S3 output from the X scan D / A converter 25 is increased (step S3). Then X
The displacement signal is A / D converted (step S4), and the X displacement data D5 obtained thereby is compared with the X displacement value Δx0 of the X target register (step S5).

Here, the X displacement data D5 is the X displacement value Δx.
If it has not reached 0, the increment of the X scan data D3 is repeated and the voltage of the X scan signal is increased (repeating steps S3 to S5). On the other hand, X displacement data D5
If the X displacement value Δx0 has been reached, it means that the measurement point has been reached, so the X scan data D3 data (that is, X
The applied voltage data Vx0) is stored in the address (in this case, the head) designated by the table pointer of the X displacement information table (step S6).

Next, the X table pointer is incremented (step S7), and the X table pointer becomes 2.
Whether or not it is 56 is compared (step S8). If it is not 256, the X displacement value Δx1 corresponding to the X scanning position of the next measurement point is set in the X target register (step S2).
After that, the sequence of steps S2 to S8 is repeated to create the X displacement information table.

When the X table pointer reaches 256 in step S8, the X scan data D3 is decremented and the X scan data D3 is decremented until the X scan data D3 becomes equal to or less than Vx0 which is the top value of the X displacement information table. A converter 25
The voltage of the X-scanning signal S3 output from is reduced (steps S9 and S10). In other words, until the scanning origin is reached, S
After the scanning, the X preliminary scanning is completed.

FIG. 6 shows a one-line measurement scan of the sample surface information using the X displacement table created by the above sequence. Next, the processing operation of the one-line measurement scan will be described with reference to the flowchart of FIG.

The measurement scan of the sample 29 is started in the state where the two-dimensional scan of the piezoelectric body 27 is at the head point of the first scan line (scan origin in FIG. 2). Then, first, "0" is initialized to the X table pointer (step S11). Next, the X scan data D3 is incremented, and the voltage of the X scan signal S3 output from the X scan D / A converter 25 is increased (step S12).

The X displacement information (X applied voltage data Vx) designated by the X table pointer is read from the X displacement information table (step S13) and compared with the X scan data D3 (step S14).

When the X scan data D3 has not reached the X displacement information (X applied voltage data Vx), the X scan data D3 is repeatedly incremented and the voltage of the X scan signal is increased. That is, the above steps S12-
S14 is repeated. On the other hand, when the X scanning data D3 has reached the X displacement information (X applied voltage data Vx), it means that the measurement point has been reached, and therefore the sample surface information (Z unevenness data D2 in this case) is detected. And is transferred to the host computer 21 to be imaged (step S1).
5).

After the X table pointer is incremented (step S16), it is compared whether or not the value of the X table pointer is 256 (step S17).
Here, if the value of the X table pointer is not 256, the sequence of steps S12 to S17 is repeated. On the other hand, when the number reaches 256, "0" is set in the X table pointer (step S18).

Thereafter, the X-scan data D3 is decremented and the voltage of the X-scan signal S3 output from the X-scan D / A converter 25 is reduced until the X-scan data D3 becomes equal to or lower than Vx0 which is the top value of the X-displacement information table. Is lowered (steps S19 to S21). That is, until the scanning measurement start point is reached, X scanning is performed and one line measurement scanning is completed.

In this way, the X displacement information table is prepared by the preliminary scanning in the X direction and the one-line measurement scanning in the X direction for the sample surface information (Z unevenness) is performed. Thereafter, as shown in FIG. 7, when the Y direction preliminary scanning is performed similarly to the X direction preliminary scanning, the Y displacement information table as shown in FIG. 5B can be created.

If one line measuring scan of the sample surface information is repeated for a plurality of lines while gradually scanning in the Y direction using the Y displacement information table, the sample surface information for one frame can be measured. it can.

FIGS. 7A to 7H are timing charts of 1-frame measurement scans when such 1-line measurement scans of the sample surface information are repeated for 256 lines.
7 (a), (b), (c), and (d) are diagrams corresponding to FIGS. 4 (a), (c), (d), and (e), respectively. Then, scanning and measurement in the Y direction are performed at the timings shown in FIGS. 7E to 7H.

Regarding the operation in the Y direction, the above-mentioned X
The description is omitted here because it follows the directional operation. Next, a second embodiment of the present invention will be described.

In the first embodiment described above, preparation of the X displacement information table in the case where the displacement detection resolution of the displacement sensor is a wide scanning range that can be sufficiently resolved with respect to the measurement point interval for measuring the sample surface information has been described. .

In the second embodiment described below, when the displacement detection resolution of the X displacement sensor is coarser than the measurement point interval for measuring the sample surface information in the narrow scanning range, the X displacement information (X applied voltage data Vxn) is interpolated to create a high resolution X displacement information table.

8A and 8B show X in the narrow scanning range.
In the direction preliminary scan, the X displacement sensor can detect only 128 points with the highest resolution displacement detection for the 256 measurement points of the sample surface information on one scanning line.
It is the figure which showed the mode of a scanning signal and an X displacement signal. Also,
8C is an enlarged view of the vicinity of Vx0 of the X scanning signal of FIG. 8A, and FIG. 8D is Δx of the X displacement signal of FIG. 8B.
It is the figure which expanded 0 vicinity.

In the X direction preliminary scan, X displacement data D
When 5 reaches the X displacement value Δx0, it means that the measurement point at the head of the X displacement table is reached. Therefore, the X scan data D3 data (that is, the X applied voltage data Vx
0) is stored at the address of the X table pointer 0 of the X displacement information table.

Next, the X displacement data D5 is the X displacement value Δx1.
If it reaches, the X scan data D3 data (that is,
The X applied voltage data Vx1) is stored at the address of the X table pointer.

At this time, Vx1.5 = (Vx1 + Vx2) / 2 is calculated and stored in the address of the X table pointer 1. That is, at the address where the X table pointer is 2n (n = 0 to 127), the X displacement value Δ
X applied voltage data Vxn corresponding to xn is stored.
Further, the X table pointer is 2n + 1 (n = 0 to 12).
At the address 7), X applied voltage data Vxn corresponding to the X displacement value Δxn and X corresponding to the X displacement value Δxn + 1.
Applied voltage data Vxn + 1 to Vxn. 5 = (Vn + Vn + 1) / 2 is calculated and stored.

As a result, the created high resolution X displacement information table is as shown in FIG. 9 (a). still,
By a similar method, a high resolution Y displacement information table as shown in FIG. 9B can be created. In the second embodiment, using these high resolution displacement tables, the sample surface information is scanned and measured with high resolution in the same manner as in the first embodiment.

Further, in the above-described second embodiment, the interpolation is performed by the simple first-order approximation. However, in the case where the number of points to be interpolated is increased due to the narrower range scanning, a plurality of points before and after are interpolated. From the displacement detection points, it is possible to create a high-resolution displacement information table along the actual hysteresis curve by quadratic approximation, tertiary approximation, or other approximation.

Further, by creating a table by an interpolation method or the like when the scanning range becomes narrow, it is possible to obtain a higher resolution than the accuracy of the sensor and perform scanning measurement even in a narrow scanning range.

Next, a third embodiment of the present invention will be described. In the above-described first and second embodiments, after the displacement information table is created once in the preliminary scanning step, the sample surface information is measured without updating the displacement information table in the measurement scanning step. In the third embodiment described below, two lines of X and Y displacement information tables are prepared, and sample surface information is measured using the X displacement information table at each X scanning line in the measurement scanning stage. At the same time, a next X displacement information table used for the next X line scanning measurement is created.

Further, when the X scan moves to the next scan line, the Y displacement information table is used to perform the Y scan, and at the same time, the next Y line scan (that is, the next frame measurement scan).
The next Y displacement information table used for is created. That is,
At the measurement scanning stage, the X displacement information table is updated for each line and the Y displacement information table is updated for each frame, and the sample surface information is measured.

The operation of the table creation simultaneous measurement scan sequence for creating the next X displacement information table for the next X line measurement scan while measuring the sample surface information will be described below with reference to the flowchart of FIG.

In the measurement scan of the sample 29, the X preliminary scan for creating the X displacement information table is completed, and the two-dimensional scan of the piezoelectric body 37 is the first scan line start point (scan origin in FIG. 2).
It will be started in the state.

First, "0" is initialized to the X table pointer and the next X table pointer (step S4).
1, S42). Subsequently, the X displacement value Δx0 corresponding to the X scanning position of the first measurement point is set in the X target register (step S43). Next, the Y scan data D3 is incremented and the voltage of the X scan signal S3 output from the X scan D / A converter 25 is increased (step S
44). Then, the sample surface information detection process (step S4
5 to S48).

In the sample surface information detection processing, the X displacement information (X applied voltage data Vx) designated by the X table pointer is read from the X displacement information table (step S).
45) and compared with the X scan data D3 (step S4).
6). If the X scan data D3 has not reached the X displacement information (X applied voltage data Vx), the process proceeds to the table creation process (steps S49 to S52).

On the other hand, in step S46, when the X scan data D3 reaches the X displacement information, the sample surface information (in this case, the Z unevenness data D2) is detected and transferred to the host computer 21. And imaged (step S47). Then, after the X table pointer is incremented (step S48), the process proceeds to the table creation process (steps S49 to S52).

In the table creating process, the X displacement signal is A /
The X displacement data D5 obtained by the D conversion is compared with the X displacement value Δx0 of the X target register (step S5).
0, S51). Then, the X displacement data D5 is the X displacement value Δ.
If x0 has not been reached, the process proceeds to the forward scan end comparison process (steps S54 and S55). On the other hand, if it has reached, it means that the measurement point of the next scan line has been reached, so the X scan data D3 data (that is, X applied voltage data Vx0) is indicated by the next table pointer of the next X displacement information table. It is stored in the address (the head in this case) (step S51).

Next, the X table pointer is incremented (step S52), and the X displacement value Δx0 corresponding to the X scanning position of the next measurement point is set in the X target register (step S53). After that, the process proceeds to the forward scan end processing (steps S54 to S58).

Forward scan end processing (steps S54 to S5)
In 8), it is compared whether or not both the X table pointer and the next X table pointer are 256 or more (steps S54 and S55). If none of them exceeds 256, the X scan data D3 is incremented, the voltage of the X scan signal S3 output from the X scan D / A converter 25 is increased (step S44), and the sample surface information processing ( Steps S45 to S48) and the table creation process (steps S49 to S53) are repeated.

On the other hand, when both are 256 or more, the Vx data group stored in the next X displacement table is transferred and stored in the X displacement table (step S56).
After that, "0" is set to the X table pointer (step S57), and the X displacement value Δx0 corresponding to the X scanning position of the first measurement point of the next line is set to the X target register (step S58).

Then, the subsequent backward scanning process (step S5)
9 to S62), the X scan data D3 is less than Vx0 which is the top value of the X displacement information table (steps S60 and S61),
Further, until the X displacement data D5 obtained by A / D converting the X displacement signal becomes less than the X displacement value Δx0 of the X target register (steps S62 and S63), the X scanning data D3 is decremented and the X scanning is performed. The voltage of the X scan signal S3 output from the D / A converter 25 is lowered (step S
59). That is, the X scan is performed until the next line scan measurement start point is reached, and the 1 line measurement scan ends.

As described above, in the third embodiment, the process of simultaneously preparing the X displacement information table and measuring the sample surface information (Z unevenness) at the time of one-line measurement scanning in the X direction has been described in detail. When the scan shifts to the next scan line, the Y displacement information table is used to perform the Y scan, and at the same time, the next Y displacement information table used for the next Y line scan (that is, the next frame measurement scan) may be created. It can be easily achieved by modifying the above sequence.

That is, it is possible to measure the sample surface information while updating the X displacement information table line by line and the Y displacement information table frame by frame at the measurement scanning stage. Therefore, more real-time measurement of the sample surface information can be performed.

In the above-mentioned embodiment of the present invention, the sample surface shape is measured as the AFM.
It goes without saying that the present invention can be applied to all other scanning probe microscopes such as STM, nc-AFM, and MFM.

In the above embodiment, the microcomputer may be replaced with a control IC such as DSP,
Of course, it is possible to replace the logic IC with the logic IC to perform the matching detection, the magnitude comparison, the increment, the decrement, etc. performed by the microcomputer.

Further, in the embodiment, the optical sensor is used as the displacement sensor of the piezoelectric body, but the capacitance sensor,
It is also possible to replace with another sensor such as a laser length measuring sensor. In addition, it goes without saying that those output signals are not limited to analog signals, and even if they are digital signals, they can be replaced with logic ICs that change to A / D.

Further, the piezoelectric applied voltage data Vx and Vy are used as the displacement information stored in the displacement information table.
It is also possible to use the timer built in the microcomputer or another timer IC to use the scanning times Tx and Ty as the displacement information stored in the displacement information table. Furthermore, other physical information can be used as the displacement information.

In addition, in the above-described embodiment, the displacement information table is created and the sample surface information is measured during the forward scan, but the displacement information table is created and the sample surface information is measured during the backward scan. Of course, it is possible to create the displacement information table and measure the sample surface information during both the forward scan and the backward scan.

According to the above embodiment of the present invention, the following constitution can be obtained. (1) A piezoelectric body for scanning a probe or a sample,
Driving means for deforming the piezoelectric body in at least one of the XYZ directions, displacement detecting means for detecting displacement of the piezoelectric body in at least one of the XYZ directions, and measurement of the piezoelectric body at a point where sample surface information should be measured. An information table for storing point displacement information, a table creating means for pre-storing the measurement point displacement information of the sample surface information in the information table during preliminary scanning before measuring the sample surface information, and the sample surface information A scanning probe microscope comprising: a measuring unit that measures the sample surface information at a measurement point based on the measurement point displacement information stored in the information table during measurement scanning.

(2) The table creating means stores the piezoelectric body applied voltage or the scanning time at the time when the displacement detection value by the displacement detecting means reaches the point where the sample surface information should be measured as the measuring point displacement information. The scanning probe microscope according to (1) above, wherein the scanning probe microscope is stored in a means.

(3) The table creating means uses the piezoelectric body applied voltage or the scanning time at the time when the displacement detection value by the displacement detecting means reaches the point where the sample surface information should be measured as the measuring point displacement information. The scanning probe microscope according to the above (1) or (2), characterized in that, when the measurement point displacement information is stored in the table, an information table exceeding the displacement detection resolution is created by interpolation.

(4) A piezoelectric body for scanning a probe or a sample, driving means for deforming the piezoelectric body in at least one of the XYZ directions, and displacement detection for detecting displacement of the piezoelectric body in at least one of the XYZ directions. Means, an information table for storing displacement information of the measurement point of the piezoelectric body at the point where the sample surface information is to be measured, and the sample surface information at the measurement point based on the displacement information of the measurement point of the information table at the time of one line scanning. A scanning probe microscope, comprising: a table creation simultaneous measurement scanning unit that creates a table for the next line measurement scan while measuring

(5) The table creation simultaneous measurement scanning means measures the piezoelectric applied voltage or the scanning time at the time when the displacement detection value by the displacement detection means reaches the point where the sample surface information should be measured. The scanning probe microscope according to (4) above, wherein the scanning probe microscope is stored in the storage means.

(6) The table creation simultaneous measurement scanning means measures the piezoelectric applied voltage or the scanning time at the time when the displacement detection value by the displacement detecting means reaches the point where the sample surface information should be measured. The scanning probe microscope according to the above (4) or (5), characterized in that, when the measurement point displacement information is stored as the information table, an information table exceeding the displacement detection resolution is created.

According to the above configuration (1), the displacement detection means continues to detect the displacement while voltage-driving the piezoelectric body at a resolution higher than the number of points at which the preliminary scanning is performed to measure the sample surface information. It detects whether the displacement has reached the displacement of the preset measurement point, and the piezoelectric body applied voltage or scanning time is stored in the information table as the displacement information of the measurement point for each point where the displacement reaches the measurement point. After storing and completing the preliminary scan, the measurement scan is performed and the piezoelectric applied voltage or scan time
The sample surface information is measured and imaged at the point where the measurement point displacement information stored in the information table is reached. Therefore,
An image with high linearity can be obtained without slowing down the scanning speed.

According to the configurations (2) and (3), when the information table is created, the displacement information is created by interpolating the measurement point displacement information such as the piezoelectric applied voltage or the scanning time to create the table. The sample surface information can be measured with a resolution higher than the displacement resolution of the detection means, and an image with high resolution and high linearity can be obtained without slowing the scanning speed.

According to the above configuration (4), the information table created during the preliminary scanning is prepared while measuring the sample surface information based on the measurement point displacement information stored in the information table during each line measurement scanning. By creating it for line measurement scanning, an image with high resolution and high linearity with less drift can be obtained without slowing down the scanning speed.
Further, according to the above configurations (5) and (6), when the information table is created, the displacement detection is performed by creating the table by interpolating the measurement point displacement information such as the piezoelectric applied voltage or the scanning time. The sample surface information can be measured with a resolution higher than the displacement resolution of the means, and an image with high resolution and high linearity can be obtained without slowing the scanning speed.

[0077]

As described above, according to the present invention, the sample surface is not affected by the displacement of the piezoelectric body and the voltage hysteresis characteristic, does not decrease the scanning speed, and has high resolution and high linearity and high accuracy. A scanning probe microscope capable of measuring information can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a scanning probe microscope according to the present invention.

FIG. 2 is a diagram showing the positional relationship between the sample and the tip of the cantilever at the time of preliminary scanning for creating a displacement information table and measurement scanning of the sample surface in the scanning probe microscope of the present invention.

FIG. 3 shows a scanning probe microscope X of the present invention.
7 is a flowchart illustrating an operation of creating a displacement information table in which the piezoelectric body applied voltage at the measurement point X displacement during preliminary scanning is used as displacement information.

4A and 4B are timing charts for creating a displacement information table during X preliminary scanning, in which FIG. 4A is a diagram showing an X scanning D / A conversion timing, and FIG. 4B is a diagram showing an X displacement A / D conversion timing. (C) is a diagram showing an X scan signal, and (d) is an X scan signal.
The figure which showed the displacement signal, (e) is the figure which showed the X displacement table storage timing.

5A is a diagram showing an X displacement information table, FIG.
(B) is a diagram showing a Y displacement information table.

FIG. 6: 1 on the sample surface using the X displacement information table
It is a flow chart explaining operation of line measurement scanning.

7A and 7B are timing charts of 1-frame measurement scanning in which 1-line measurement scanning of sample surface information is repeated for 256 lines, FIG. 7A is a diagram showing X-travel XD / A conversion timing, and FIG. 7B is an X-scan signal. FIG. 6C is a diagram showing a Y displacement signal, FIG. 7D is a diagram showing uneven sampling timing based on an X displacement table, and FIG. 7E is a Y scan D / A.
The figure which showed conversion timing, (f) the figure which showed the Y scanning signal, (g) the figure which showed the Y displacement signal, (h) the figure which showed the next X line scanning start timing based on the Y displacement table. Is.

8A and 8B show the highest resolution of the X displacement sensor with respect to 256 measurement points of sample surface information on one scanning line in the X direction preliminary scanning in the narrow scanning range. The figure which shows the state of the X scanning signal and the X displacement signal when only 128 points can be detected by the displacement detection, (c) is the same figure (a)
3 is an enlarged view of the vicinity of Vx0 of the X scanning signal of FIG. 3 (d), and is an enlarged view of the vicinity of Δx0 of the X displacement signal of FIG.

9A and 9B are diagrams showing a high resolution displacement information table created according to the second embodiment, in which FIG. 9A is a high resolution X displacement information table, and FIG. 9B is a diagram showing a high resolution Y displacement information table. is there.

FIG. 10 is a flowchart illustrating the operation of a table creation simultaneous measurement scanning sequence for creating a next X displacement information table for a next X line measurement scan while measuring sample surface information according to the third embodiment of the present invention. Is.

FIG. 11 is a block diagram showing a schematic configuration of an example of a conventional scanning probe microscope.

12 is a perspective view showing the relationship among the displacement sensor, the piezoelectric body, and the sample table in FIG.

13 is a diagram showing hysteresis characteristics of applied voltage and displacement of the piezoelectric body of FIG.

[Explanation of symbols]

21 ... Host computer, 22 ... Timer, 23 ... Microcomputer, 24 ... Z control unit, 25 ... X scan D /
A converter, 26 ... Y scanning D / A converter, 27 ... XYZ driving cylindrical piezoelectric body, 28 ... Sample stage, 29 ... Sample, 30 ...
Probe displacement detector, 31 ... Cantilever (probe), 32 ...
Mirror body, 33 ... X displacement sensor, 34 ... Y displacement sensor, 37
... X displacement information table, 38 ... Y displacement information table.

Claims (3)

[Claims] 1. A piezoelectric body for scanning a probe or a sample, drive means for deforming the piezoelectric body in at least one of the XYZ directions, and displacement detection means for detecting displacement of the piezoelectric body in at least one of the XYZ directions. Information storage means for storing displacement information of the measurement point of the piezoelectric body at the point where sample surface information is to be measured, and measurement of the sample surface information in the information storage means during preliminary scanning before measuring the sample surface information. A table creating means for storing the point displacement information in advance and the sample surface information is measured at the measuring point based on the measuring point displacement information stored in the information storing means at the time of measurement scanning for measuring the sample surface information. A scanning probe microscope, comprising: a measuring unit. 2. The table creating means stores the piezoelectric body applied voltage or scanning time when the displacement detection value by the displacement detecting means reaches a point where the sample surface information should be measured as the measuring point displacement information. The scanning probe microscope according to claim 1, wherein the scanning probe microscope is stored. 3. The table storing means stores the information as the piezoelectric applied voltage or the scanning time when the displacement detection value by the displacement detecting means reaches the point where the sample surface information should be measured as the measuring point displacement information. When storing in the means,
The scanning probe microscope according to claim 1 or 2, wherein the measurement point displacement information is interpolated to create an information table having a displacement detection resolution higher than that.