JP5223832B2 - Internal structure measuring method and internal structure measuring device - Google Patents

Description

  The present invention relates to an internal structure measuring method and an internal structure measuring apparatus.

  When measuring defects in a Si wafer or a structure inside a sample such as an electronic device, a TEM (Transmission Electron Microscope) or the like is used. However, when observing using TEM or the like, it is necessary to destroy the sample for measurement.

  For this reason, there is a need for a method for measuring defects in Si wafers and structures inside electronic devices without destroying the sample. As such internal structure measuring methods, X-rays and ultrasonic waves are used. The microscope that existed exists. However, the resolution in a microscope using X-rays or ultrasonic waves is several hundred nm, and there are finer defects in the Si wafer, and finer measurement may be required even in electronic devices and the like. For example, as a microscope using ultrasonic waves, there are ultrasonic microscopy, ultrasonic force microscopy, and scanning near-field ultrasound. However, it is possible to sufficiently measure defects and structures inside the sample. Can not.

Japanese Patent No. 2730673 Special table 2009-511876

  For this reason, an internal structure measuring method and an internal structure measuring apparatus that can measure the internal structure of a sample with high resolution without destroying the sample are desired.

  According to one aspect of the present embodiment, a resonance frequency measurement step of measuring the resonance frequency f1 of the sample, and the sample is vibrated by the resonance frequency f1 of the sample, and the cantilever that is in contact with the sample is contacted with the sample. A surface measurement step for measuring a distribution of surface vibrations, a FEM calculation model for the sample based on a distribution of surface vibrations in the sample, a resonance frequency calculation step for calculating a resonance frequency f2 in the FEM calculation model, and the resonance A resonance frequency comparison step of comparing the frequency f1 and the resonance frequency f2, and in the resonance frequency comparison step, if the value of the resonance frequency f1 and the value of the resonance frequency f2 are not substantially equal, Based on the distribution of the surface vibration of the sample, the FEM calculation model is changed and the resonance frequency calculation step and the resonance frequency comparison step are performed again. , Wherein when the value of the resonant frequency f1 and the value of the resonant frequency f2 is approximately equal, characterized in that the FEM calculation model regarded as the structure of the sample.

  According to another aspect of the present embodiment, a resonance frequency measurement step for measuring the resonance frequency f1 of the sample, and a first surface measurement for measuring the surface state of the sample via a cantilever brought into contact with the sample. And a second surface measurement step of measuring the distribution of surface vibrations in the sample via the cantilever in a state where the sample is vibrated by the resonance frequency f1 of the sample and is separated from the surface of the sample by a certain distance; The FEM calculation model of the sample is created based on the surface vibration distribution in the sample, and the resonance frequency calculation step of calculating the resonance frequency f2 in the FEM calculation model is compared with the resonance frequency f1 and the resonance frequency f2. A resonance frequency comparison step, and in the resonance frequency comparison step, the value of the resonance frequency f1 is not substantially equal to the value of the resonance frequency f2. In this case, the FEM calculation model is changed based on the surface vibration distribution of the sample and the resonance frequency calculation step and the resonance frequency comparison step are performed again, and the values of the resonance frequency f1 and the resonance frequency f2 are substantially equal. If equal, the FEM calculation model is regarded as the structure of the sample.

According to another aspect of this embodiment, a vibration unit for resonating the sample by resonance frequency f1 of the sample, in a state in which a certain distance from the front surface of the contact or the sample surface of the sample, the A cantilever for measuring the surface vibration distribution of the sample and an FEM calculation model for the sample based on the surface vibration distribution of the sample are created. It has a calculation part which calculates distribution, and a comparison judgment part which compares resonance frequency f1 of the sample and resonance frequency f2 calculated in the calculation part.

  According to the disclosed internal structure measuring method and internal structure measuring apparatus, the internal structure of the sample can be measured with high resolution without destroying the sample.

Configuration diagram of internal structure measuring apparatus according to the first embodiment Distribution diagram of surface vibration measured by internal structure measuring apparatus in first embodiment Flowchart of internal structure measuring method in the first embodiment Explanatory drawing (1) of the internal structure measuring method in 1st Embodiment Explanatory drawing (2) of the internal structure measuring method in 1st Embodiment Flowchart of internal structure measurement method in second embodiment Explanatory drawing (1) of the internal structure measuring method in 2nd Embodiment Explanatory drawing (2) of the internal structure measuring method in 2nd Embodiment

  The form for implementing is demonstrated below.

[First Embodiment]
A first embodiment will be described. The internal structure measuring apparatus and the internal structure measuring method in the present embodiment can measure a defect in an Si wafer and an internal structure of an electronic device or the like with high resolution.

(Internal structure measuring device)
First, the internal structure measuring apparatus in the present embodiment will be described based on FIG. The internal structure measuring apparatus according to the present embodiment includes a sample setting unit 12, a vibrating unit 13, a three-dimensional stage 14, a cantilever 15, a laser light source 16, a photodetector 17, and excitation for setting a sample 11 for measuring the internal structure. A portion 18 is provided.

  The vibrating unit 13 is for vibrating the sample 11 and vibrates the sample 11 with ultrasonic waves supplied from a high-frequency signal generator 22 described later.

  The three-dimensional stage 14 moves the sample 11 in a three-dimensional direction. Therefore, an XY axis drive circuit 19 for moving the sample 11 in the XY axis direction and a Z axis drive circuit 20 for moving the sample 11 in the Z axis direction are connected to the three-dimensional stage 14.

  The cantilever 15 is for measuring the surface state of the sample 11 and detecting vibration in the sample 11. Specifically, it is a cantilever used in a scanning probe microscope (SPM) or the like. When the cantilever 15 detects the vibration in the sample 11, the vibration is detected through the air between the sample 11 and the tip of the cantilever 15.

  The laser light source 16 is for detecting the vibration of the cantilever 15. That is, the laser light from the laser light source 16 is irradiated on the back surface of the cantilever 15 (the surface opposite to the side in contact with the sample 11), and the irradiated laser light is reflected on the back surface of the cantilever 15 to detect light. It enters the detector 17 and is detected. In the vibration detection unit 21, vibration in the cantilever 15 is detected based on the light incident on the photodetector 17. Thereby, the surface state of the sample 11 can be measured via the cantilever 15.

  The excitation unit 18 is for vibrating the cantilever 15 at a high frequency, for example, 100 kHz as necessary.

  Further, the vibration unit 13 and the excitation unit 18 are connected to a high-frequency signal generator 22. The high frequency signal generator 22 can generate an arbitrary high frequency signal, and can independently vibrate the vibration unit 13 and the excitation unit 18 at a desired frequency.

  Further, the XY axis drive circuit 19, the Z axis drive circuit 20, and the high frequency signal generator 22 are connected to the apparatus control unit 23, and are controlled by each. Further, the apparatus control unit 23 is connected to the processing unit 24 together with the vibration detection unit 21.

  The processing unit 24 includes a calculation unit 25 and a comparison determination unit 26. The calculation unit 25 has a function of calculating by FEM (Finite Element Method) and creating an FEM calculation model as necessary. In the comparison / determination unit 26, for example, the resonance frequency of the sample 11 obtained by the calculation unit 25 is compared with the resonance frequency of the sample 11 actually measured, and the resonance of the sample 11 obtained by the calculation unit 25 is compared. It has a function of determining whether or not the frequency is within a predetermined range. Note that the comparison / determination unit 26 may have a function of not only determining the resonance frequency alone but also developing the calculation result and the actual measurement result in a two-dimensional bitmap to compare and determine.

  In addition, a recording unit 27 such as a hard disk drive is connected to the device control unit 23 and can record measured information and the like. In addition, a display unit 28 such as a monitor is connected to the processing unit 24, and various information can be displayed.

  In the internal structure measuring apparatus according to the present embodiment, the vibration unit 13 causes the sample 11 to vibrate at the resonance frequency. In the structure constituting the sample 11 and the like, a value determined only by “mass” and “rigidity” is called an eigenmode or a resonance mode. The eigenvalue in the resonance mode is a value that is not affected by the external force, depends on the size, shape, mechanical property value, and the like of the structure serving as the sample 11, and is dynamic specific to the structure serving as the sample 11. It is a value that represents a characteristic. In general, such a resonance mode is referred to as “natural frequency” or “resonance frequency”. In the present embodiment, since the sample 11 is vibrated by the resonance frequency, the ultrasonic wave is not attenuated even inside the sample 11. Therefore, internal defects and structures can be measured with high resolution.

  FIG. 2 shows a distribution diagram of the surface vibration of the sample 11 when the sample 11 is vibrated at the resonance frequency by the vibration unit 13. Since the sample 11 vibrates at the resonance frequency, a region with a small amplitude (MIN) and a region with a large amplitude (MAX) are formed on the surface of the sample 11, and the surface vibration amplitude of the sample 11 is detected with high resolution. can do.

(Internal structure measurement method)
Next, the internal structure measuring method in the present embodiment will be described based on FIG. The internal structure measurement method according to the present embodiment is a method in which the cantilever 15 is brought into contact with the surface of the sample 11 and is a measurement method suitable for measuring the sample 11 having a relatively flat surface.

  First, in step 102 (S102), the resonance frequency of a reference sample serving as a reference is measured. Specifically, the ultrasonic wave applied to the reference sample serving as a reference is changed from a low frequency to a high frequency, and the resonance frequency f0 is measured by using a laser Doppler measuring instrument as the resonance frequency. Note that the resonance frequency of the reference sample can also be measured by the internal structure measuring apparatus shown in FIG. Specifically, the reference sample is set on the sample setting unit 12, and the vibrating unit 13 is vibrated based on the ultrasonic wave from the high frequency signal generating unit 22, and the reference sample is vibrated accordingly. At this time, the apparatus control unit 23 controls the high frequency signal generation unit 22 to change the ultrasonic wave generated from the high frequency signal generation unit 22 from a low frequency to a high frequency. The surface vibration of the reference sample is transmitted to the cantilever 15, and the resonance frequency f0 can be obtained by setting the frequency at which the amplitude in the reference sample is maximum as the resonance frequency. In this embodiment, a silicon substrate or the like having no defect is used as the reference sample.

  Next, in step 104 (S104), the resonance frequency of the sample 11 serving as a measurement sample is measured. Specifically, the resonance frequency f1 of the sample 11 is measured by the same method as in step 102, that is, a method using a laser Doppler measuring instrument or a method using the internal structure measuring apparatus shown in FIG. Note that the sample 11 is a measurement target, and may include, for example, a silicon substrate that may contain a defect or the like, or a film that is formed on the silicon substrate. .

  Next, in step 106 (S106), it is determined whether or not a defect or the like exists in the sample 11 that is a measurement sample. Specifically, when the resonance frequency f0 of the reference sample and the resonance frequency f1 of the sample 11 substantially coincide with each other, it is determined that there is no defect or the like inside the sample 11, and the process ends. On the other hand, when the resonance frequency f0 of the reference sample and the resonance frequency f1 of the sample 11 do not substantially coincide with each other, it is determined that a defect or the like exists in the sample 11, and the internal structure of the sample 11 is determined. The process proceeds to step 108 for measurement.

  Next, in step 108 (S108), a distribution diagram of surface vibrations in the sample 11 is obtained (resonance mode measurement). Specifically, the sample 11 is vibrated at the resonance frequency f1, and the cantilever 15 is brought into contact with the surface of the sample 11 to perform two-dimensional measurement, thereby obtaining a surface vibration distribution map of the sample 11. In the present embodiment, the sample 11 is vibrated at 2.43 MHz, which is the resonance frequency f1 of the sample 11 obtained in step 104, to obtain a distribution diagram of the surface vibration of the sample 11 as shown in FIG.

  Next, in step 110 (S110), an FEM calculation model is created. Specifically, when defects such as voids are included, generally, the resonance frequency f0 of the reference sample and the resonance frequency f1 of the sample 11 are different from each other, and in the distribution diagram of the surface vibration of the sample 11 A pattern having an asymmetric region is obtained. Therefore, in the processing unit 24 or the calculation unit 25 in the processing unit 24, the size and structure of defects such as voids and the defect concentration so as to match the distribution diagram of the resonance frequency f1 of the sample 11 and the surface vibration of the sample 11. Is selected and an FEM calculation model is created.

  Next, in step 112 (S112), the resonance frequency in the FEM calculation model is calculated. Specifically, the calculation unit 25 calculates the resonance frequency f2 in the FEM calculation model created in step 110, and further obtains a surface vibration distribution map of the FEM calculation model as necessary.

  Next, in step 114 (S114), the resonance frequency f1 of the sample 11 that is an actual measurement value is compared with the resonance frequency f2 that is a calculation value calculated in step 112. In this case, not only the resonance frequencies of the actually measured value and the calculated value are compared with each other, but also when the distribution diagram of the surface vibration is calculated in step 112, the distribution diagram and calculation of the surface vibration of the actually measured sample 11 are used. You may compare with the obtained distribution map of surface vibration.

  Next, in step 116 (S116), it is determined whether or not the value of the resonance frequency f2 that is the calculated value calculated in step 112 and the value of the resonance frequency f1 of the sample 11 that is the actual measurement value substantially match. . As to whether or not the calculated value of the resonance frequency f2 and the actually measured value of the resonance frequency f1 are substantially the same, the value of the resonance frequency f2 is included in a certain range with respect to the resonance frequency f1. You may judge by whether or not. When it is determined that the calculated value of the resonance frequency f2 and the actually measured value of the resonance frequency f1 are substantially the same, the FEM calculation model created in step 110 shows the structure of the sample 11. It is determined that it is reflected and the process ends. If it is determined that the calculated value of the resonance frequency f2 and the actually measured value of the resonance frequency f1 do not substantially match, the routine proceeds to step 110. In addition to comparing only the resonance frequencies as described above, when the surface vibration distribution map is calculated in step 112, the surface vibration distribution map of the measured sample 11 and the surface vibration obtained by the calculation are calculated. It may be judged by comparing with the distribution map of.

  This determination will be specifically described. FIG. 4A is a distribution diagram of surface vibration obtained by FEM in the case where no defect exists in the silicon substrate or the like as shown in FIG. Calculated as 42 MHz. On the other hand, FIG. 5A is a distribution diagram of surface vibrations obtained by FEM in the case where defects such as voids exist in a silicon substrate or the like as shown in FIG. The frequency is calculated as 2.43 MHz. Since the value of the actually measured resonance frequency f1 in the sample 11 is 2.43 MHz, it matches the resonance frequency in the case shown in FIG. Further, comparing the distribution diagram of the surface vibration of the sample 11 shown in FIG. 1 with the distribution diagram of the surface vibration obtained by the FEM calculation model, the distribution diagram of the surface vibration of the sample 11 shown in FIG. 5 is closer to the surface vibration distribution diagram shown in FIG. 5A than the surface vibration distribution diagram shown in FIG. Therefore, it is determined that the FEM calculation model for obtaining the distribution diagram of the surface vibration shown in FIG. 5A represents the internal structure of the sample 11. Therefore, as shown in FIG. 5B, it is determined that a void exists inside the silicon substrate or the like that is the sample 11.

  Note that the chi-square test may be used for comparison and determination of the calculated value and the actually measured value in step 114 and step 116. In this case, in step 116, the FEM calculation model in which the chi-square value is minimized, not whether or not the value of the resonance frequency f2 that is the calculated value and the value of the resonance frequency f1 that is the actually measured value are substantially the same. It is determined that the actual internal structure of the sample 11 is matched.

  The model of FEM calculation obtained in this way reflects the structure of the sample 11. Therefore, by using the FEM calculation model, even when defects, voids, holes, etc. exist deep inside the sample 11, these defects, voids, holes, etc. can be measured and detected with high resolution. .

[Second Embodiment]
Next, a second embodiment will be described. The internal structure measurement method in the present embodiment is a measurement method suitable for a case where a relatively large number of irregularities are formed on the surface of the sample 11. The internal structure measuring method in the present embodiment will be described based on FIG. In addition, the internal structure measuring method in this Embodiment is performed using the internal structure measuring apparatus in 1st Embodiment.

  First, in step 202 (S202), the resonance frequency of a reference sample serving as a reference is measured. Specifically, the ultrasonic wave applied to the reference sample serving as a reference is changed from a low frequency to a high frequency, and the resonance frequency f0 is measured by using a laser Doppler measuring instrument as the resonance frequency. Note that the resonance frequency of the reference sample can also be measured by the internal structure measuring apparatus shown in FIG. Specifically, the reference sample is set on the sample setting unit 12, and the vibrating unit 13 is vibrated based on the ultrasonic wave from the high frequency signal generating unit 22, and the reference sample is vibrated accordingly. At this time, the apparatus control unit 23 controls the high frequency signal generation unit 22 to change the ultrasonic wave generated from the high frequency signal generation unit 22 from a low frequency to a high frequency. The surface vibration of the reference sample is transmitted to the cantilever 15, and the resonance frequency f0 can be obtained by setting the frequency at which the amplitude in the reference sample is maximum as the resonance frequency. In this embodiment, a silicon substrate or the like having no defect is used as the reference sample.

  Next, in step 204 (S204), the resonance frequency of the sample 11 to be measured is measured. Specifically, the resonance frequency f1 of the sample 11 is measured by the same method as in step 202, that is, a method using a laser Doppler measuring instrument or a method using the internal structure measuring apparatus shown in FIG. Note that the sample 11 is a measurement target, and may include, for example, a silicon substrate that may contain a defect or the like, or a film that is formed on the silicon substrate. .

  Next, in step 206 (S206), it is determined whether or not a defect or the like exists in the sample 11 that is a measurement sample. Specifically, when the resonance frequency f0 of the reference sample and the resonance frequency f1 of the sample 11 substantially coincide with each other, it is determined that there is no defect or the like in the sample 11, and the process ends. On the other hand, when the resonance frequency f0 of the reference sample and the resonance frequency f1 of the sample 11 do not substantially coincide with each other, it is determined that a defect or the like exists in the sample 11, and the internal structure of the sample 11 is determined. The process proceeds to step 208 for measurement.

  Next, in step 208 (S208), the uneven shape on the surface of the sample 11 as the measurement sample is measured. Specifically, as shown in FIG. 7, the sample 11 is not vibrated, and the cantilever 15 is brought into contact with the surface of the sample 11 to measure two-dimensionally, thereby obtaining a two-dimensional surface shape of the sample 11. The obtained information is recorded in the recording unit 27 and the like. Note that the cantilever 15 may be vibrated at 100 kHz in the excitation unit 18, for example, in order to increase measurement accuracy.

  Next, in step 210 (S210), a distribution map of surface vibrations in the sample 11 is obtained (resonance mode measurement). Specifically, as shown in FIG. 8, the sample 11 is vibrated at the resonance frequency f <b> 1, and the surface of the sample 11 is two-dimensionally measured by the cantilever 15 with a certain distance from the surface of the sample 11. . Thereby, the distribution map of the surface vibration of the sample 11 can be obtained. In the present embodiment, the sample 11 is vibrated at the resonance frequency f1 in the sample 11 obtained in step 204, and the cantilever 15 is separated at a constant interval along the two-dimensional surface shape in the sample 11 measured in step 208. Is moved two-dimensionally. Thereby, the distribution map of the surface vibration of the sample 11 can be obtained. Specifically, by moving the tip of the cantilever 15 along the broken line 31 in FIG. 8, the distance from the sample 11 to the cantilever 15 can be made constant, and the surface vibration of the sample 11 is made uniform on the cantilever 15. Can communicate. Thereby, the amplitude in the sample 11 can be detected more accurately. Further, the cantilever 15 may be vibrated at 100 kHz in the excitation unit 18, for example, in order to increase the measurement accuracy.

  Next, in step 212 (S212), an FEM calculation model is created. Specifically, when defects such as voids are included, generally, the resonance frequency f0 of the reference sample and the resonance frequency f1 of the sample 11 are different from each other, and in the distribution diagram of the surface vibration of the sample 11 A pattern having an asymmetric region is obtained. Therefore, in the processing unit 24 or the calculation unit 25 in the processing unit 24, the size and structure of defects such as voids and the defect concentration so as to match the distribution diagram of the resonance frequency f1 of the sample 11 and the surface vibration of the sample 11. Is selected and an FEM calculation model is created.

  Next, in step 214 (S214), the resonance frequency in the FEM calculation model is calculated. Specifically, the calculation unit 25 calculates the resonance frequency f2 in the FEM calculation model created in step 212, and further obtains a surface vibration distribution map of the FEM calculation model as necessary.

  Next, in step 216 (S216), the resonance frequency f1 of the sample 11 that is an actual measurement value is compared with the resonance frequency f2 that is a calculation value calculated in step 214. In this case, not only the resonance frequencies of the actually measured value and the calculated value are compared, but also when the distribution diagram of the surface vibration is calculated in step 214, the distribution diagram and calculation of the surface vibration of the measured sample 11 are used. You may compare with the obtained distribution map of surface vibration.

  Next, in step 218 (S218), it is determined whether or not the value of the resonance frequency f2 that is the calculated value calculated in step 214 is substantially equal to the value of the resonance frequency f1 of the sample 11 that is the actual measurement value. . As to whether or not the calculated value of the resonance frequency f2 and the actually measured value of the resonance frequency f1 are substantially the same, the value of the resonance frequency f2 is included in a certain range with respect to the resonance frequency f1. You may judge by whether or not. If it is determined that the calculated value of the resonance frequency f2 and the actually measured value of the resonance frequency f1 are substantially the same, the FEM calculation model created in step 212 shows the structure of the sample 11. It is determined that it is reflected and the process ends. If it is determined that the calculated value of the resonance frequency f2 and the actually measured value of the resonance frequency f1 do not substantially match, the process proceeds to step 212. In addition to comparing only the resonance frequencies as described above, when the distribution diagram of the surface vibration is calculated in step 214, the distribution diagram of the surface vibration of the sample 11 measured and the surface vibration obtained by the calculation are calculated. It may be judged by comparing with the distribution map of.

  It should be noted that a chi-square test may be used for comparison and determination between the calculated value and the actually measured value in step 216 and step 218. In this case, in step 218, it is determined that the FEM calculation model in which the chi-square value is minimal matches the actual internal structure of the sample 11 instead of whether or not the calculated value is within a predetermined range. Is done.

  The FEM calculation model obtained in this way reflects the structure of the sample 11, and when there are defects, voids, holes, etc. deep inside the sample 11, these defects, voids, Holes and the like can be measured and detected with high resolution.

  In the first and second embodiments, a minute structure inside the sample can be measured with high resolution. Therefore, it is possible to obtain information on nanostructures such as nanoparticles, dislocations, and voids existing inside the sample without destroying the sample.

  In particular, in the second embodiment, since the cantilever 15 is not brought into contact with the sample 11 in a state where the sample 11 is vibrated with ultrasonic waves, the sample 11 is not destroyed and is not destroyed. The internal structure can be measured with high resolution. Therefore, it is suitable for the measurement of the internal structure of a thin film, organic material, cell, etc. having low strength.

  In addition, since the first and second embodiments are measurement methods using a vibration field (sound field), they are not affected by an electromagnetic field. Therefore, an electric field analysis using an SCM (Scanning Capacitance Microscope), an SRM (Scanning Spread Resistance Microscope), an EFM (Electrostatic Force Microscope) or the like using an SPM, and a magnetic field analysis using an MFM (Magnetic Force Microscope) can be performed simultaneously. Thereby, a plurality of measurements and analyzes can be performed in a short time, and the measurement and analysis of the sample can be performed at low cost.

  Although the embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes can be made within the scope described in the claims.

In addition to the above description, the following additional notes are disclosed.
(Appendix 1)
A resonance frequency measurement step of measuring the resonance frequency f1 of the sample;
A surface measurement step of vibrating the sample at a resonance frequency f1 of the sample and measuring a distribution of surface vibrations in the sample via a cantilever brought into contact with the sample;
Creating a FEM calculation model of the sample based on the distribution of surface vibrations in the sample, and calculating a resonance frequency f2 in the FEM calculation model;
A resonance frequency comparison step of comparing the resonance frequency f1 and the resonance frequency f2.
In the resonance frequency comparison step, if the value of the resonance frequency f1 is not substantially equal to the value of the resonance frequency f2, the FEM calculation model is changed based on the distribution of the surface vibration of the sample. The resonance frequency calculation step and the resonance frequency comparison step are performed again, and when the value of the resonance frequency f1 is substantially equal to the value of the resonance frequency f2, the FEM calculation model is regarded as the structure of the sample. Internal structure measurement method.
(Appendix 2)
A resonance frequency measurement step of measuring the resonance frequency f1 of the sample;
A first surface measurement step of measuring the surface state of the sample via a cantilever brought into contact with the sample;
A second surface measurement step of oscillating the sample at a resonance frequency f1 of the sample and measuring a distribution of surface vibrations in the sample via the cantilever in a state separated from the surface of the sample by a certain distance;
Creating a FEM calculation model of the sample based on the distribution of surface vibrations in the sample, and calculating a resonance frequency f2 in the FEM calculation model;
A resonance frequency comparison step of comparing the resonance frequency f1 and the resonance frequency f2.
In the resonance frequency comparison step, when the value of the resonance frequency f1 and the value of the resonance frequency f2 are not substantially equal, the FEM calculation model is changed again based on the surface vibration distribution of the sample. A resonance frequency calculation step and a resonance frequency comparison step are performed, and when the value of the resonance frequency f1 is substantially equal to the value of the resonance frequency f2, the FEM calculation model is regarded as the structure of the sample. Structure measurement method.
(Appendix 3)
In the second surface measurement step, the cantilever is moved in a state separated by a certain distance based on the shape of the surface state of the sample measured in the first surface measurement step. 2. The internal structure measuring method according to 2.
(Appendix 4)
4. The internal structure measuring method according to appendix 2 or 3, wherein, in the first surface measurement step, the cantilever is vibrated at a frequency different from the resonance frequency f1.
(Appendix 5)
The internal structure measuring method according to any one of appendices 2 to 4, wherein, in the second surface measurement step, the cantilever is vibrated at a frequency different from the resonance frequency f1.
(Appendix 6)
The surface vibration distribution of the sample is detected by irradiating the surface of the cantilever opposite to the side where the sample and the cantilever are in contact with the laser beam and detecting the laser beam reflected on the opposite surface. The internal structure measuring method according to any one of appendices 1 to 5, characterized in that:
(Appendix 7)
In the resonance frequency calculation step, when creating an FEM calculation model of the sample, voids, vacancies, or dislocation defects are added to the FEM calculation model. Structure measurement method.
(Appendix 8)
Before the resonance frequency measurement step, a reference sample resonance frequency measurement step of measuring a resonance frequency f0 of a reference sample having no defects different from the sample;
An initial resonance frequency comparison step of comparing the resonance frequency f0 of the reference sample with the resonance frequency f1 of the sample;
The internal structure measuring method according to any one of appendices 1 to 7, wherein:
(Appendix 9)
The resonance frequency calculation step can also obtain a distribution of surface vibrations of the FEM calculation model when the FEM calculation model is vibrated at the resonance frequency f2.
In the resonance frequency comparison step, the surface vibration distribution of the sample is compared with the surface vibration distribution of the FEM calculation model, and the surface vibration distribution of the sample and the surface vibration distribution of the FEM calculation model are obtained. If they are not approximately equal, the FEM calculation model is changed and the resonance frequency calculation step and the resonance frequency comparison step are performed again. The surface vibration distribution of the sample and the surface vibration distribution of the FEM calculation model are approximately equal. In the case, the internal structure measuring method according to any one of appendices 1 to 8, wherein the FEM calculation model is regarded as a structure of the sample.
(Appendix 10)
A vibrating section for causing the sample to resonate at the resonance frequency f1 of the sample;
A cantilever for measuring the surface vibration distribution of the sample in contact with the surface of the sample or at a distance from the mirror surface of the sample;
A FEM calculation model for the sample based on the surface vibration distribution of the sample;
A comparison / determination unit that compares the resonance frequency f1 of the sample with the resonance frequency f2 calculated by the calculation unit;
An internal structure measuring device comprising:
(Appendix 11)
The surface vibration distribution of the sample is detected by irradiating the surface of the cantilever opposite to the side where the sample and the cantilever are in contact with the laser beam and detecting the laser beam reflected on the opposite surface. 11. The internal structure measuring device according to appendix 10, wherein the internal structure measuring device is measured.

DESCRIPTION OF SYMBOLS 11 Sample 12 Sample installation part 13 Vibration part 14 Three-dimensional stage 15 Cantilever 16 Laser light source 17 Photodetector 18 Excitation part 19 XY axis drive circuit 20 Z axis drive circuit 21 Vibration detection part 22 High frequency signal generator 23 Device control part 24 Process Unit 25 calculation unit 26 comparison determination unit 27 recording unit 28 display unit

Claims (6)

A resonance frequency measurement step of measuring the resonance frequency f1 of the sample;
A surface measurement step of vibrating the sample at a resonance frequency f1 of the sample and measuring a distribution of surface vibrations in the sample via a cantilever brought into contact with the sample;
Creating a FEM calculation model of the sample based on the distribution of surface vibrations in the sample, and calculating a resonance frequency f2 in the FEM calculation model;
A resonance frequency comparison step of comparing the resonance frequency f1 and the resonance frequency f2.
In the resonance frequency comparison step, if the value of the resonance frequency f1 is not substantially equal to the value of the resonance frequency f2, the FEM calculation model is changed based on the distribution of the surface vibration of the sample. The resonance frequency calculation step and the resonance frequency comparison step are performed again, and when the value of the resonance frequency f1 is substantially equal to the value of the resonance frequency f2, the FEM calculation model is regarded as the structure of the sample. Internal structure measurement method. A resonance frequency measurement step of measuring the resonance frequency f1 of the sample;
A first surface measurement step of measuring the surface state of the sample via a cantilever brought into contact with the sample;
A second surface measurement step of oscillating the sample at a resonance frequency f1 of the sample and measuring a distribution of surface vibrations in the sample via the cantilever in a state separated from the surface of the sample by a certain distance;
Creating a FEM calculation model of the sample based on the distribution of surface vibrations in the sample, and calculating a resonance frequency f2 in the FEM calculation model;
A resonance frequency comparison step of comparing the resonance frequency f1 and the resonance frequency f2.
In the resonance frequency comparison step, when the value of the resonance frequency f1 and the value of the resonance frequency f2 are not substantially equal, the FEM calculation model is changed again based on the surface vibration distribution of the sample. A resonance frequency calculation step and a resonance frequency comparison step are performed, and when the value of the resonance frequency f1 is substantially equal to the value of the resonance frequency f2, the FEM calculation model is regarded as the structure of the sample. Structure measurement method.   The surface vibration distribution of the sample is detected by irradiating the surface of the cantilever opposite to the side where the sample and the cantilever are in contact with the laser beam and detecting the laser beam reflected on the opposite surface. The internal structure measuring method according to claim 1, wherein the internal structure is measured. The resonance frequency calculation step can also obtain a distribution of surface vibrations of the FEM calculation model when the FEM calculation model is vibrated at the resonance frequency f2.
In the resonance frequency comparison step, the surface vibration distribution of the sample is compared with the surface vibration distribution of the FEM calculation model, and the surface vibration distribution of the sample and the surface vibration distribution of the FEM calculation model are obtained. If they are not approximately equal, the FEM calculation model is changed and the resonance frequency calculation step and the resonance frequency comparison step are performed again. The surface vibration distribution of the sample and the surface vibration distribution of the FEM calculation model are approximately equal. In this case, the internal structure measuring method according to any one of claims 1 to 3, wherein the FEM calculation model is regarded as a structure of the sample. A vibrating section for causing the sample to resonate at the resonance frequency f1 of the sample;
In certain distance away than that the front surface of the contact or the sample surface of the sample, the cantilever for measuring the distribution of surface vibration of the sample,
A calculation unit that creates an FEM calculation model in the sample based on a distribution of surface vibrations of the sample, and calculates a resonance frequency f2 in the FEM calculation model and a distribution of surface vibrations in the FEM calculation model;
A comparison / determination unit that compares the resonance frequency f1 of the sample with the resonance frequency f2 calculated by the calculation unit;
An internal structure measuring device comprising:   The surface vibration distribution of the sample is detected by irradiating the surface of the cantilever opposite to the side where the sample and the cantilever are in contact with the laser beam and detecting the laser beam reflected on the opposite surface. The internal structure measuring device according to claim 5, wherein:

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