System and method for measuring contact potential and relative permittivity

Abstract

To provide a measuring method capable of simply measuring a contact potential and a relative dielectric constant by utilizing an existing device.SOLUTION: In the Kelvin probe measurement method, a variable voltage power source is electrically connected between a sample to be measured and probe electrodes, distances between the sample to be measured and the probe electrodes are periodically changed, and a current I1 flowing between the sample to be measured and the probe electrodes or a signal voltage I1 after amplifying the current V1 is measured. A contact potential VC is obtained from a voltage V applied by a variable voltage power source when a current I1 or a signal voltage V1 becomes 0, and a relative dielectric constant ε is obtained from ε = ε ' * α / α ' using a slope α of a characteristic curve drawn by a peak-to-peak value Vpeak-to-peak of the signal voltage V1 with respect to the voltage V applied by the variable voltage power source and a slope α ' of a characteristic curve obtained by measuring a reference sample made of a material having a known relative dielectric constant ε ' under the same conditions as those for obtaining the characteristic curve.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system and method for measuring contact potential and relative dielectric constant. [Background technology]

[0002] The contact potential and relative dielectric constant are important physical properties for the design, fabrication, and quality control of electronic devices. The contact potential can be measured by the Kelvin probe method (KP method), and the relative dielectric constant can be measured by, for example, the capacitance method, the lumped parameter method, and the resonance method.

[0003] The KP method is a method for easily determining the contact potential of a conductive material by electrically connecting a variable voltage power supply between a sample (specimen) made of a conductive material and a probe electrode, periodically changing the distance between the sample and the probe electrode, and measuring the current I1 flowing between the sample and the probe electrode or the signal voltage V1 after amplifying the current I1. For example, this method is disclosed in Patent Document 1 and Non-Patent Document 1.

[0004] A system for measuring both contact potential and relative dielectric constant is disclosed in, for example, Patent Document 2. This system includes equipment for the KP method and equipment for measuring dielectric constant, which is made up of equipment for CV measurement and charging. The dielectric constant measurement there includes a charging process step of contactlessly charging the surface of the insulating film to be measured, a step of determining a first flat band voltage by performing contactless CV measurement of the semiconductor substrate with respect to the insulating film before the charging process step, a step of determining a second flat band voltage by performing contactless CV measurement of the semiconductor substrate with respect to the insulating film after the charging process step, and a charge amount measurement step including a step of calculating the amount of charge imparted to the insulating film surface by the charging process step from the difference between the first and second flat band voltages, a surface potential measurement step of contactlessly measuring the surface potential of the insulating film with respect to the insulating film after the charging process step, and a step of calculating the relative dielectric constant of the insulating film from the amount of charge measured in the charge amount measurement step and the surface potential measured in the surface potential measurement step.

[0005] As can be seen in this example, conventionally, systems for measuring both contact potential and dielectric constant have required a combination of dedicated equipment, which makes the devices complex and costly, and the measurements take a long time. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2018-519533 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-111911 [Non-patent literature]

[0007] [Non-Patent Document 1] Akira Tahara, Toshiaki Kodama, Zairyo-to-Kankyo, 46, 717-723 (1997) Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a measurement system and a measurement method that can solve the above-mentioned conventional problems and utilize existing devices to easily measure contact potential and relative dielectric constant. [Means for solving the problem]

[0009] The configuration of the present invention to solve the problems is shown below. (Configuration 1) A measurement method using a Kelvin probe measurement method, in which a variable voltage power supply is electrically connected between a sample to be measured and a probe electrode, the distance between the sample to be measured and the probe electrode is periodically changed, and a current I1 flowing between the sample to be measured and the probe electrode or a signal voltage V1 after amplifying the current I1 is measured, When the current I1 or the signal voltage V1 becomes 0, the contact potential VC Seeking The amplitude width V of the signal voltage V1 with respect to the applied voltage V by the variable voltage power supply peak to peak and a slope α' of a characteristic curve obtained by measuring a reference sample made of a material having a known relative dielectric constant ε' under the same conditions as those for obtaining the characteristic curve. ε=ε′×α / α′ This is a measurement method for measuring contact potential and relative permittivity, in which the relative permittivity ε is calculated from the above. (Configuration 2) A measurement system using a Kelvin probe measurement device, comprising: a sample stage on which a sample to be measured is placed; a probe electrode arranged opposite the sample to be measured; a vibration device that periodically changes the distance between the sample to be measured and the probe electrode; a variable voltage power supply electrically connected between the sample to be measured and the probe electrode; a measurement device that measures a current I1 flowing between the sample to be measured and the probe electrode or a signal voltage V1 after amplifying the current I1; and an analysis means that analyzes a signal from the probe electrode, the vibration equipment periodically changes the distance between the sample to be measured and the probe electrode; The measuring device measures a current I1 flowing between the sample under test and the probe electrode or a signal voltage V1 obtained by amplifying the current I1; The analysis means calculates the contact potential V when the voltage V applied by the variable voltage power supply becomes zero. C Seeking The amplitude width V of the signal voltage V1 with respect to the applied voltage V by the variable voltage power supply peak to peak and a slope α' of a characteristic curve obtained by measuring a reference sample made of a material having a known relative dielectric constant ε' under the same conditions as those for obtaining the characteristic curve. ε=ε′×α / α′ This is a contact potential and relative permittivity measurement system that calculates the relative permittivity ε from the above. [Effects of the Invention]

[0010] According to the present invention, a measurement system and a measurement method are provided that can easily measure contact potential and relative dielectric constant by utilizing an existing device for the KP method. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a configuration diagram showing the configuration of a processing device used in the present invention. [Figure 2] FIG. 1 is a flowchart showing an outline of a processing flow of the present invention. [Figure 3] FIG. 10 is a flowchart showing the flow of pre-processing according to the present invention. [Figure 4] FIG. 10 is a flowchart showing the flow of the main measurement process of the present invention. [Figure 5] FIG. 10 is a characteristic diagram showing the relationship between the sample-probe electrode distance and the FFT2 / FFT1 component ratio. [Figure 6] FIG. 10 is a characteristic diagram showing the relationship between applied voltage and signal intensity. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Device> The measuring device used in the present invention is similar to the device used in the KP method, in which a variable voltage power supply is electrically connected between the sample to be measured and the probe electrode, the distance between the sample to be measured and the probe electrode is periodically changed, and the current I1 flowing between the sample to be measured and the probe electrode or the signal voltage V1 after amplifying the current I1 is measured. 1, the measuring device 101 comprises a sample stage 14 on which a sample (sample) 11 to be measured is placed, a probe electrode 12 arranged opposite the sample 11 with an average distance d0 between them, a vibration device (vibration means) 13 such as a moving coil or voice coil that vibrates the probe electrode 12, a variable voltage power supply 17 that applies a variable voltage to the probe electrode 12, an ammeter that monitors the signal strength from the probe electrode, such as a current value, or a signal strength monitor 18 that monitors the signal voltage V1 after amplifying the signal current I1, earth 19, a housing 15, and a rod 16 that connects the housing 15, the probe electrode 12, and the vibration device 13. Here, the vibration applied to the probe electrode 12 may be, for example, a simple harmonic motion d A sin(ωt+φ) can be used preferably.

[0013] <Measurement of contact potential> A method for measuring the contact potential Vc of the sample 11 will be described with reference to FIG. 1, which is a diagram showing a measuring device.

[0014] As a preparation for measurement, a reference sample for which the contact potential Vc' has been previously determined is used to measure the voltage offset ΔV caused by the device, such as the leakage field at the probe electrode material or electrode edge, according to the following procedure. For example, rolled gold plate or polycrystalline gold can be used as the reference sample. Stainless steel (SUS304, SUS316, etc.) can also be used.

[0015] First, a reference sample (standard sample) is placed on the sample stage 14 of the measuring device 101, and the height of the sample stage 14 is adjusted so that the distance between the surface of the reference sample and the probe electrode 12 becomes a predetermined distance d0. This distance adjustment is not limited to adjusting the height of the sample stage 14, but may also be performed by adjusting the height of the probe electrode 12, or by combining the height adjustment of the probe electrode 12 and the height adjustment of the sample stage 14. Here, if the distance d0 is too wide, the detected signal strength will decrease, the noise component will increase, and measurement accuracy will decrease. On the other hand, since the probe electrode 12 is vibrated by the vibration equipment 13 during measurement, sufficient clearance must be secured between the probe electrode 12 and the reference sample so that the probe electrode 12 does not come into contact with the reference sample during this vibration. The distance d0 is set from three perspectives: signal strength, noise level, clearance, and sample handling.

[0016] Next, while vibrating the probe electrode 12 with the vibration equipment 13, an applied voltage V is applied to the probe electrode 12 with the variable voltage power supply 17 to obtain an output signal. Here, the output signal may be a current value I1 directly obtained by the ammeter 18, or a signal voltage V1 obtained by amplifying the current I1.

[0017] Next, the applied voltage V is applied (swept) over a specified range to obtain the characteristic curve of the reference sample (I1 = f'(V) or V1 = f'(V)), and the applied voltage V at which f'(V) = 0 is determined. From this value and the previously determined contact potential Vc' of the reference sample, the voltage offset ΔV due to the device is calculated according to (Equation 1). ΔV=V-Vc′ …(Formula 1)

[0018] Thereafter, the actual measurement is carried out using the sample to be measured (sample) 11. This measurement follows the procedure of the pre-measurement preparation described above.

[0019] First, the sample 11 is placed on the sample stage 14 of the measuring device 101, and the height of the sample stage 14 is adjusted so that the distance between the surface of the sample 11 and the probe electrode 12 becomes the above-mentioned distance d0.

[0020] Next, while vibrating the probe electrode 12 with the vibration equipment 13, an applied voltage V is applied to the probe electrode 12 with the variable voltage power supply 17 to obtain an output signal. Here, the output signal may be a current value I1 directly obtained by the ammeter 18, or a signal voltage V1 obtained by amplifying the current I1. Next, the voltage V is applied (swept) over a predetermined range to obtain the characteristic curve of the sample 11 (I1 = f(V) or V1 = f(V)), and the applied voltage V at which f(V) = 0 is determined. From this value and the potential offset ΔV calculated above, the contact potential Vc of the sample 11 is calculated according to (Equation 2). Vc=V+ΔV…(Formula 2) By this method, the contact potential Vc of the sample 11 is determined.

[0021] <Measurement of relative permittivity> The method for measuring the relative dielectric constant ε of the sample 11 will be described with reference to FIG. 1, which is a diagram showing the measurement apparatus.

[0022] As a preparation for measurement, a reference sample whose relative dielectric constant ε' has been determined in advance is used, and the slope α' of the characteristic curve of that reference sample is measured according to the following procedure. Here, for example, rolled gold sheet or polycrystalline gold can be used as the reference sample. Stainless steel (SUS304, etc.) can also be used. The relative dielectric constant ε' of metals can be considered to be approximately 1.

[0023] First, a reference sample is placed on the sample stage 14 of the measurement apparatus 101, and the height of the sample stage 14 is adjusted so that the distance between the surface of the reference sample and the probe electrode 12 becomes a predetermined distance d0. As described in the contact potential measurement section, this distance adjustment is not limited to adjusting the height of the sample stage 14, but may also be performed by adjusting the height of the probe electrode 12, or by combining the height adjustment of the probe electrode 12 and the height adjustment of the sample stage 14. Here, if the distance d0 is too wide, the detected signal strength will decrease, the noise component will increase, and measurement accuracy will be reduced. Meanwhile, since the probe electrode 12 is vibrated by the vibration equipment 13 during measurement, sufficient clearance must be secured between the probe electrode 12 and the reference sample to prevent the probe electrode 12 from coming into contact with the reference sample during this vibration. The distance d0 is set from three perspectives: signal strength, noise level, clearance, and sample handling. It is preferable to set the distance d0 to the same distance d0 set during contact potential measurement, as this reduces the setup time and increases data compatibility.

[0024] Next, while vibrating the probe electrode 12 with the vibration equipment 13, an applied voltage V is applied to the probe electrode 12 with the variable voltage power supply 17 to obtain an output signal. Here, the output signal may be a current value I1 directly obtained by the ammeter 18, or a signal voltage V1 obtained by amplifying the current I1.

[0025] Next, the applied voltage V is swept over a specified range to obtain the characteristic curve of the reference sample (I1 = f'(V) or V1 = f'(V)), and the applied voltage V at which f'(V) = 0 is determined. From this value and the previously determined contact potential Vc' of the reference sample, the voltage offset ΔV due to the device is calculated according to (Equation 1). ΔV=V-Vc′ …(Formula 1) Also, the slope α' of the characteristic curve f' of the reference sample is found. Here, if the characteristic curve f' of the reference sample can be approximated by a linear function, the slope α' at any V may be used.

[0026] Thereafter, the actual measurement is carried out using the sample to be measured (sample) 11. This measurement follows the procedure of the pre-measurement preparation described above.

[0027] First, the sample 11 is placed on the sample stage 14 of the measuring device 101, and the height of the sample stage 14 is adjusted so that the distance between the surface of the sample 11 and the probe electrode 12 becomes the distance d0 set during the reference electrode measurement. This distance adjustment is not limited to adjusting the height of the sample stage 14, but may also be performed by adjusting the height of the probe electrode 12, or by combining the height adjustment of the probe electrode 12 and the height adjustment of the sample stage 14, as in the case of the reference sample.

[0028] Next, while vibrating the probe electrode 12 with the vibration equipment 13, an applied voltage V is applied to the probe electrode 12 with the variable voltage power supply 17 to obtain an output signal. Here, the output signal may be a current value I1 directly obtained by the ammeter 18, or a signal voltage V1 obtained by amplifying the current I1.

[0029] Next, the applied voltage V is scanned over a predetermined range to obtain the characteristic curve of the sample 11 (I1 = f(V) or V1 = f(V)), and the slope α of the characteristic curve f of the sample 11 is determined. Here, since the characteristic curve f of the sample 11 can be approximated by a linear function, the slope α at any V can be used.

[0030] Finally, the relative dielectric constant ε of the sample 11 is calculated using the slope α of the characteristic curve of the sample 11 obtained by measurement and the slope α' of the characteristic curve of the reference sample, according to the following (Equation 3). ε=ε′×α / α′ (Formula 3) When a metal is used as the reference sample, ε' is approximately 1, so ε=α / α′ (Equation 4) The relative dielectric constant ε of the sample 11 can be obtained by

[0031] <Simultaneous measurement of contact potential Vc and relative dielectric constant ε> The simultaneous measurement of contact potential Vc and relative dielectric constant ε will be explained with reference to process flow chart diagrams of Figures 2-4.

[0032] As a preparation before measurement (step S1 in Figure 2), a reference sample (standard sample) whose contact potential Vc' and relative permittivity ε' have been determined in advance is used to measure the offset voltage ΔV due to the device and the slope α' of the characteristic curve of that reference sample according to the following procedure. Here, for example, rolled gold sheet or polycrystalline gold can be used as the reference sample. Stainless steel (such as SUS304) can also be used. The relative permittivity ε' of metals can be considered to be approximately 1.

[0033] First, a reference sample is placed on the sample stage 14 of the measuring device 101, and the height of the sample stage 14 is adjusted so that the distance between the surface of the reference sample and the probe electrode 12 becomes a predetermined distance d0 (step S11). As described in the contact potential measurement section, this distance adjustment is not limited to adjusting the height of the sample stage 14, but may also be performed by adjusting the height of the probe electrode 12, or by combining the height adjustment of the probe electrode 12 and the height adjustment of the sample stage 14. Here, if the distance d0 is too wide, the detected signal strength will decrease, the noise component will increase, and measurement accuracy will be reduced. Meanwhile, since the probe electrode 12 is vibrated by the vibration equipment 13 during measurement, sufficient clearance must be secured between the probe electrode 12 and the reference sample to prevent the probe electrode 12 from coming into contact with the reference sample during this vibration. The distance d0 is set from three perspectives: signal strength, noise level, clearance, and sample handling. It is preferable to set the distance d0 to the same distance d0 set during contact potential measurement, as this reduces the setup time and increases data compatibility.

[0034] Next, while vibrating the probe electrode 12 with the vibration equipment 13, an applied voltage V is applied to the probe electrode 12 with the variable voltage power supply 17 to obtain an output signal (step S12). Here, the output signal may be a current value I1 directly acquired by the ammeter 18, or may be a signal voltage V1 obtained after amplifying the current I1.

[0035] Next, the voltage V is applied (swept) over a predetermined range to obtain the characteristic curve of the reference sample (I1 = f'(V) or V1 = f'(V)), and the applied voltage V at which f'(V) = 0 is determined (step S13). From this value and the previously determined contact potential Vc' of the reference sample, the voltage offset ΔV due to the device is determined according to the above-mentioned (Equation 1) (step S14). Here, there are no particular limitations on the method of applying the voltage V, but sweeping is efficient and preferable. Furthermore, the slope α' of the characteristic curve f' of the reference sample is determined from the characteristic curve of the reference sample (I1 = f'(V) or V1 = f'(V)) (step S15). Here, since the characteristic curve f' of the reference sample can be approximated by a linear function, the slope α' at any V may be used.

[0036] Thereafter, the actual measurement (step S2) is carried out using the sample to be measured 11. This measurement follows the procedure of the pre-measurement preparation described above.

[0037] First, the sample 11 is placed on the sample stage 14 of the measuring device 101, and the height of the sample stage 14 is adjusted so that the distance between the surface of the sample 11 and the probe electrode 12 becomes the distance d0 set during the reference electrode measurement (step S21). This distance adjustment is not limited to adjusting the height of the sample stage 14, but may also be performed by adjusting the height of the probe electrode 12, or by combining the height adjustment of the probe electrode 12 and the height adjustment of the sample stage 14, as in the case of the reference sample.

[0038] Next, while vibrating the probe electrode 12 with the vibration equipment 13, an applied voltage V is applied to the probe electrode 12 with the variable voltage power supply 17 to obtain an output signal (step S22). Here, the output signal may be a current value I1 directly acquired by the ammeter 18, or may be a signal voltage V1 obtained by amplifying the current I1. The amplitude of vibration of the probe electrode 12 is not particularly limited, but may be 0.1 mm when d0 is 0.5 mm, for example.

[0039] Next, the applied voltage V is swept over a predetermined range to obtain the characteristic curve of the sample 11 (I1 = f(V) or V1 = f(V)), and the applied voltage V at which f(V) = 0 is determined (step S23). From this value and the potential offset ΔV determined above, the contact potential Vc of the sample 11 is determined according to the aforementioned (Equation 2) (step S24). By this method, the contact potential Vc of the sample 11 is determined.

[0040] Furthermore, the slope α of the characteristic curve f of the sample 11 (I1=f(V) or V1=f(V)) is determined (step S25). Here, since the characteristic curve f of the sample 11 can be approximated by a linear function, the slope α at any V may be used.

[0041] Finally, the relative permittivity ε of the sample 11 is calculated using the slope α of the characteristic curve of the sample 11 obtained by measurement and the slope α' of the characteristic curve of the reference sample, using the above-mentioned (Equation 3) (step S26). When a metal is used as the reference sample, ε' is approximately 1, so the relative dielectric constant ε of sample 11 can be found using the above-mentioned (Equation 4). Through the above steps, the contact potential Vc and the relative dielectric constant ε of the sample 11 can be easily measured simultaneously.

[0042] <How to set the sample-probe electrode gap> The key point of this measurement method is to measure the reference sample, the sample under test, the contact potential, and the dielectric constant uniformly at a distance d0 between the surface of the sample and the probe electrode 12. One of the causes of this is the fringe effect, which is the leakage electric field at the edge between the sample 11 and the probe electrode 12. The fringe effect occurs when the distance between the probe electrodes becomes smaller, as the strength of the electric field at the center increases, and the influence of the leakage electric field at the edge becomes smaller. If the distance between the sample 11 and the probe electrode 12 changes, the influence of the leakage electric field increases, which in turn changes the measurement conditions. It is possible to modify the device to deal with the influence of the leakage electric field or to correct the distortion through calculations and reflect this in the measurement, but this would complicate the device and measurement, increase costs, and reduce measurement efficiency, which goes against the simplicity that is one of the purposes of this invention. Therefore, in order to measure the contact potential Vc and the relative dielectric constant ε simply and accurately under a leakage electric field, the present invention employs a measurement method in which the distance between the probe electrode 12 and the sample is standardized to d0.

[0043] Measurements can be performed with a uniform distance d0 by using additional position measurement and position reflection methods, such as setting the sample height position taking into account the sample thickness and inclination, and reflecting the results of surface position measurements using lasers, LEDs, or spray air pressure.However, by reflecting the Fourier component measurements described below, it is also possible to set the distance between the sample surface and the probe electrode 12 to a uniform distance for all measurements. In this method, the signal components are subjected to Fourier analysis (FFT processing) to find the intensity ratio between the first Fourier component FFT1 and the second Fourier component FFT2, and the principle is used that if this ratio is constant, the interval is constant.

[0044] In the KP method using Fourier analysis, characteristic function data I1 = f1(V, d) is acquired by applying a (sweep) voltage V from a variable voltage power supply and adjusting the height of the sample stage 14. Here, d is the distance between the sample surface and the probe electrode 12. The measured signal data (characteristic function data I1 = f1(V, d) data) is subjected to Fourier signal processing to obtain the first-order Fourier component FFT1 and the second-order Fourier component FFT2, and the intensity ratio of the Fourier components (FFT2 / FFT1) is calculated. Extracting data with a constant FFT2 / FFT1 from the measured data, or adjusting the height of the sample stage to keep FFT2 / FFT1 constant, enables analysis using data measured under conditions where the distance between the sample surface and the probe electrode 12 is constant.

[0045] Figure 5 is a characteristic diagram showing the relationship between the distance d0 between the sample 11 and probe electrode 12 and the FFT2 / FFT1 ratio when the contact potential Vc of the sample 11 is 2 V, the relative dielectric constant ε is 1 or 2, the vibration frequency of the probe electrode 12 is 100 Hz, and the applied voltage V is 1 V or 2 V. It can be seen that the three pieces of data with different parameters are on a single characteristic curve. This suggests that if the height of the sample stage is adjusted so that FFT2 / FFT1 is constant and the data is collected and used, it will be possible to perform analysis using data measured under conditions where the distance between the sample surface and the probe electrode 12 is constant.

[0046] If the characteristic function I1 = f1(V, d) is found under the condition that the ratio of FFT2 / FFT1 is constant, the value of V for the characteristic function I1 = f1(V, d) when FFT1 = 0 is ΔV + Vc. Similarly, if ΔV is found by measuring a reference sample with a known contact potential Vc', the contact potential Vc of sample 11 can be found. Similarly, under the condition that the ratio of FFT2 / FFT1 is constant, the relative permittivity ε of the sample 11 can be determined by calculating using the slope α of the characteristic function I1=f1(V, d) obtained using the sample 11 under test and the slope α′ of the characteristic function I1′=f1′(V, d) obtained using the reference sample using the aforementioned (Equation 4). This method makes it possible to simultaneously measure the contact potential Vc and the relative permittivity ε of the sample 11 under test, without using any special (hardware) means for measuring the distance between the surface of the sample and the probe electrode 12. [Example]

[0047] In the example, polycrystalline gold (Au) is used as the reference sample, and a Si wafer is used as the sample 11 to be measured, and an example is shown in which the contact potential Vc and the relative dielectric constant ε of the Si wafer are obtained. The characteristic curves of the reference sample and sample 11 were obtained using the measurement method using Fourier components described in the embodiment. The results are shown in Figure 6. The slope α' of the characteristic curve for the reference sample (Au) was 0.76, and the slope α of the characteristic curve for sample 11 (Si) was 0.93. Since the relative permittivity of Au can be considered to be 1, the relative permittivity ε of sample 11 was determined to be 1.22. Furthermore, simultaneous measurements revealed that the contact potential Vc of sample 11 was 0.79. The Si wafer used was an N-type low-resistivity wafer cut out and not cleaned. Therefore, a native oxide film was formed on the surface. [Industrial Applicability]

[0048] The method and system of the present invention allows for simple and simultaneous measurement of fundamental material properties, namely, contact potential and dielectric constant, using existing equipment, and can be used for material development and quality control. Therefore, it is believed that the present method and system will contribute to the development of science and technology, as well as to the improvement of product quality and performance, i.e., industrial development. [Explanation of symbols]

[0049] 11: Sample to be measured (sample) 12: Probe electrode 13: Moving coil, voice coil, vibration equipment 14: Sample stage 15: Cabinet 16: Rod 17: Variable voltage power supply 18: Current meter, signal strength monitor 19: Earth 101: Measuring equipment

Claims

1. A variable voltage power supply is electrically connected between the sample to be measured and the probe electrode, and the distance between the sample to be measured and the probe electrode is periodically changed to measure the current I flowing between the sample to be measured and the probe electrode. １ or the current I １ The signal voltage V after amplification １ A measurement method using a Kelvin probe measurement method for measuring The current I １ or the signal voltage V １ When the voltage V applied by the variable voltage power supply becomes 0, the contact potential V Ｃ Seeking The signal voltage V １ The amplitude width V ｐｅａｋ ｔｏ ｐｅａｋ and a slope α' of a characteristic curve obtained by measuring a reference sample made of a material having a known relative dielectric constant ε' under the same conditions as those for obtaining the characteristic curve. ε = ε' × α / α' This is a measurement method for measuring contact potential and relative permittivity, in which the relative permittivity ε is calculated from the above.

2. A sample stage on which the sample to be measured is placed a probe electrode disposed opposite the sample to be measured; a vibration device for periodically changing the distance between the sample to be measured and the probe electrode; a variable voltage power supply electrically connected between the sample to be measured and the probe electrode; and a current I flowing between the sample to be measured and the probe electrode. １ or the current I １ The signal voltage V after amplification １ A measurement system using a Kelvin probe measurement device having a measurement device for measuring a temperature and an analysis means for analyzing a signal from the probe electrode, the vibration equipment periodically changes the distance between the sample to be measured and the probe electrode; The measurement device measures the current I flowing between the sample to be measured and the probe electrode. １ or the current I １ The signal voltage V after amplification １ Measure the The current I １ or the signal voltage V １ When the voltage V applied by the variable voltage power supply becomes 0, the contact potential V Ｃ Seeking The signal voltage V １ The amplitude width V ｐｅａｋ ｔｏ ｐｅａｋ and a slope α' of a characteristic curve obtained by measuring a reference sample made of a material having a known relative dielectric constant ε' under the same conditions as those for obtaining the characteristic curve. ε = ε' × α / α' This is a contact potential and relative permittivity measurement system that calculates the relative permittivity ε from the above.

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