JP2003121459A - Electric characteristic measuring device and measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure an electric characteristic of an object nondestructively. SOLUTION: A minute probe such as a cantilever arranged in a scanning probe microscope such as an intermolecular force microscope is used, and the minute probe is brought into contact with a measured material by controlling a pressure or displacement within a range of the intermolecular force. In this way, measurement based on a four probe method is carried out while a contact pressure of the minute probe to the measured object is controlled within the intermolecular force range, and contact pressure dependency or displacement dependency of an electric resistivity can be found.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor material, a metal material, a ceramic material, an organic material, and an apparatus and method for measuring electric characteristics such as electric resistivity of these materials in a liquid state.

[0002]

2. Description of the Related Art In recent years, as semiconductor devices have become higher in density and higher in performance, semiconductor materials used for semiconductor devices, metal materials, and thin films made of these materials have electrical characteristics such as electrical resistivity. It is becoming more and more important to measure. As a method for measuring the electrical characteristics of these materials, a measuring method called a 4-probe method is generally used.

In the commonly used four-point probe method, equal intervals l
Contact the material to be measured with four probes arranged in a straight line (usually about 0.5 to 1 mm) and set a fixed distance between the two probes arranged outside of the four probes. The current I is applied to measure the voltage V generated in the object to be measured by the two probes arranged inside the four probes. The 4-probe method has a feature that it can eliminate the problem caused by the contact resistance between the probe and the material to be measured by the 2-probe method.

According to the four-probe method, when the material to be measured is sufficiently large and the thickness d thereof is sufficiently large as compared with the interval 1 between the probes, the electrical resistivity value ρ is It is obtained from the following equation (1) using the voltage V and the current I. ρ = (V / I) 2πl [Ω · cm] (1) However, correction is necessary when the material to be measured is small or when the thickness d is small. For example, in the case of l >> d such as a diffusion layer of a semiconductor substrate or a thin film material, the electrical resistivity value ρ can be approximately calculated by the following equation (2). ρ = 4.54 V / dl [Ω · cm] (2) Furthermore, when the four probes are arranged not on a straight line but at each vertex of a rectangle, for example, the electrical resistivity is determined from the current and the voltage. Methods have also been reported. In either case, when the electrical resistivity is accurately measured using the 4-probe method, the area of the material to be measured is sufficiently large in the region where the probe is set up, and the physical properties are sufficiently uniform in that region. To prevent the temperature rise of the material to be measured, do not allow the current I to flow too much, and also to prevent the contact resistance between the two outer probes and the material to be measured from interfering with the supply of the predetermined current, cover the probe. It is required to satisfy each condition such as being sufficiently pressed against the measurement material.

[0005]

In the conventional 4-probe method,
Usually, in the case of gallium arsenide wafer or when contact resistance is a problem, a probe such as soft osmium is used. Measurement is performed by bringing the probe into contact with the material to be measured.

When the electrical resistivity is measured using the conventional 4-probe method, the probe is normally pressed against the object to be measured and brought into contact with the surface of the object to be measured with a force of 40 to 200 grams.
On the other hand, in the 4-probe method, the radius of curvature of the tip is 100 to 300.
A μm probe is used. Therefore, the probe applies a considerable amount of pressure per unit area to the measured object, and irrespective of the hardness of the probe, dents are unavoidably generated on the surface of the measured object, resulting in destruction of the measured object. It has a problem of tightening. Therefore, it can be said that the conventional 4-probe method is one type of destructive inspection.

Therefore, if this four-point probe method is applied to, for example, the measurement of a silicon substrate for manufacturing a semiconductor device, the surface will be scratched, and after the measurement, the substrate will be used for manufacturing a semiconductor device. Cannot be used.

In order to avoid such a problem, it is conceivable to provide a region on the silicon substrate for measuring the electrical resistivity at a predetermined place different from the place where the circuit is formed. However, since high integration of the semiconductor device is required, it is practically impossible to secure a wide area in which the conventional four-point probe method can be implemented. Therefore, in an actual semiconductor device manufacturing line, a silicon substrate (dummy wafer) for measuring the electrical resistivity is used in addition to the silicon substrate for manufacturing the semiconductor device.

This dummy wafer is used at each process step of the manufacturing process, and as a result, the consumption of the dummy wafer is about 20% of all silicon substrates consumed annually.
Have been occupied. Therefore, it must be said that the utilization efficiency of the silicon substrate is extremely low. In view of the current world situation where energy and resource conservation must be encouraged, it is of great significance to reduce the amount of dummy wafers used. For that purpose, there is a demand for a nondestructive method for measuring electric characteristics such as electric resistance and a measuring apparatus.

On the other hand, from the viewpoint of energy saving and resource saving,
Research on surface melting of metals is underway. Usually, many materials are produced through a high temperature melt, but for this purpose, it is necessary to once heat a substance to a temperature above its melting point or liquidus temperature to melt it. However, it has been reported that, in a few atomic layers on the surface of a substance, there is a phenomenon called surface melting that has the same structure as a liquid at a temperature lower than the melting point by 100 ° C. or more. If the dynamics of this phenomenon are elucidated in principle and the principle can be applied to the melting of ordinary substances, a significant reduction in energy consumption can be expected. Most of the researches on surface melting have been conducted by using the molecular dynamics method, but in order to advance the research, it is necessary to directly observe this phenomenon experimentally.

As a method of experimenting with surface melting, it has been considered to measure a change in electrical resistivity of a metal surface due to surface melting. In the conventional 4-probe method, as described above, Since the probe is pressed against the surface to be measured with a force of 200 grams, the surface melted layer is destroyed, and it becomes impossible to perform the desired measurement. Therefore, in order to promote the research and development as described above, there is a demand for a non-destructive method and apparatus for measuring electric characteristics such as electric resistivity.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned conventional problems and to nondestructively measure the electrical characteristics of an object to be measured. Another object of the present invention is to provide an electric characteristic measuring device for measuring electric characteristics such as electric resistivity without giving an indentation by a probe on the surface of a material to be measured and without destroying a surface melting layer. .

[0013]

According to the present invention, in an electric characteristic measuring apparatus and measuring method, a fine probe such as a cantilever included in a scanning probe microscope such as an atomic force microscope is used as a probe, and a range of atomic force is used. The microprobe is brought into contact with the material to be measured by controlling the pressure or displacement with. This makes it possible to perform measurement by the 4-probe method while controlling the contact pressure of the microprobe to the object to be measured within the range of the atomic force, and the contact pressure dependence or displacement dependence of the electrical resistivity. Can be asked.

It can be considered that electrical contact is realized between the microprobe and the object to be measured at the pressure at which this dependence disappears. By forming an electrical contact between the microprobe and the object to be measured in this way, it is possible to measure the electrical characteristics such as the electrical resistivity without making an impression on the surface of the object to be measured. it can.

The electrical characteristic measuring apparatus of the present invention comprises a plurality of microprobes, probe control means capable of individually controlling each microprobe in at least one axial direction, and each microprobe and the object to be measured. The detection means detects a displacement between them or a force acting between each microprobe and the object to be measured, and a measurement means having at least one pair of each microprobe as a measurement terminal. The probe control means controls the position of each micro probe in the uniaxial direction based on the output of the detection means, and the measurement means measures the electrical characteristics of the object to be measured based on the electrical detection between the measurement terminals.

The probe control means controls the displacement between the minute probe and the object to be measured or the force acting between each minute probe and the object to be measured so as to fall within the range of the atomic force. This reduces the force applied by the microprobe to the object to be measured. In this state, the measuring means performs electrical detection between the microprobes to measure the electrical characteristics.

The measuring means detects electric characteristics while changing the displacement and pressure between the microprobe and the object to be measured by the probe control means, and detects the detected electric characteristics and the pressure change or displacement change detected by the detecting means. The contact pressure dependence or displacement dependence of the electrical characteristics is measured based on Further, the measuring means obtains a pressure or displacement that eliminates this dependency based on the contact pressure dependency or displacement dependency of the measured electrical characteristic, and uses this pressure or displacement as the reference pressure or reference displacement for measuring the electrical characteristic. . The probe control means controls the position of the micro probe so that the reference pressure or the reference displacement is obtained. As a result, regardless of the object to be measured or the measurement position, it is possible to always perform measurement under stable measurement conditions.

The electrical characteristic to be measured can be, for example, the electrical resistivity or the electrical conductivity obtained from this electrical resistivity. Further, the surface melting property of the object to be measured can be obtained using the electric resistivity and the electric conductivity as indexes.
In addition, the thermal conductivity of the object to be measured can be evaluated by applying the electrical conductivity to the Wiedemann-Franz rule. Further, the plurality of microprobes arranged in the electrical characteristic measuring device can be arranged in various forms. In the case of the four-probe method, for example, a configuration in which four micro-tips are linearly arranged at equal intervals and a configuration in which four micro-tips are arranged at each vertex of a square can be adopted. When the microprobes are arranged in a square shape, it is possible to measure in a very small area. In addition to measuring one of the above measurement points, it is possible to measure a plurality of measurement points with different current directions by arranging at least two sets of measurement terminals consisting of microprobes along different axial directions. it can.

The electrical characteristic measuring method of the present invention comprises a step of detecting a displacement between a plurality of micro-tips and an object to be measured or a force acting between each micro-tip and the object to be measured, and a step of detecting means. Based on the process of individually controlling a plurality of micro-tips based on the output to control the position in at least one axis direction, and using each micro-tip as a measurement terminal, the electrical characteristics of the measured object based on the electrical detection between the measurement terminals. Each step of the step of measuring The electric characteristic measuring method of the present invention measures the contact pressure dependency or the displacement dependency of the electric characteristic by measuring the electric characteristic while changing the pressure or the displacement. Further, based on the contact pressure dependency or the displacement dependency of the electrical characteristic, a pressure value or a displacement value at which this dependency is not seen is obtained, and this value is used as a reference value for measuring the electrical characteristic value.

According to the present invention, in a semiconductor device manufacturing line, it is possible to directly measure the electrical resistivity of a substrate for production, and the measurement does not cause an indentation on the substrate surface. After that, the substrate can be returned to the manufacturing process. Therefore, it is not necessary to use a dummy wafer for measuring the electric resistivity, the ratio of the dummy wafer to all the silicon substrates used can be significantly reduced, and it can be expected that the utilization efficiency of the silicon substrate will be very high.

Further, in order to bring the microprobe into contact with the object to be measured with a force having a very small atomic force level, the surface melting process can be carried out without destroying the surface melting layer which appears in several atomic layers of the metal surface. There is a possibility that it can be detected as a change in electrical resistivity. It can be applied to research on low temperature melting of materials.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a schematic diagram for explaining the outline of the electrical characteristic measuring apparatus of the present invention. In FIG. 1, an electric characteristic measuring device 1 controls a plurality of microprobes 2 that are in contact with the surface of the measurement target S and are used as measurement terminals, and the positions of the microprobes 2 are in contact with the surface of the measurement target S. Probe control means 3, minute probe 2, and object S to be measured
Detecting means 6 for detecting the contact state with the surface of the object by pressure or displacement, measuring means 7 for measuring the electrical characteristics of the measured object S based on electrical detection using the microprobe 2 as a measuring terminal, and the measured object S. And a control means 12 for controlling the respective means as a whole. The electrical characteristic measuring device 1 includes a fine probe 2 by the probe control means 3 and the detection means 6.
Is controlled to a predetermined position with respect to the object S to be measured, and then the object S to be measured is electrically detected by the measuring means 7 using the microprobe 2 as a measurement terminal to measure the electrical characteristics.

When applying the 4-probe method, at least four microprobes 2a to 2d are arranged. The microprobes 2a to 2d may be arranged linearly at a predetermined interval, or may be arranged at each vertex of a square.
Further, with respect to the piezo element 4, the piezo control unit 5, and the detection unit 6 which constitute the probe control unit 3, the micro-probes 2a to 2a are also included.
Piezoelectric elements 4a to 4d, piezoelectric control units 5a to 5d, and detecting means 6a to 6d are provided according to the number of d.

In the following, an example of the structure to which the 4-probe method is applied will be described with reference to FIG. Each of the microprobes 2a to 2d has conductivity and is movable in the Z-axis direction (vertical axis direction) by the probe control means 3. The probe control means 3 attaches the microprobes 2a to 2d and attaches the microprobes 2a to 2d.
Of the piezo elements 4a to 4d that directly move the piezo elements, and piezo control units 5a to 5d that individually control the voltage applied to the piezo elements 4a to 4d.
The position of d is individually controlled in the Z-axis direction of each of the microprobes 2a to 2d by the corresponding piezo control unit 5a to 5d. The microprobes 2a to 2d can be configured by using a cantilever of an atomic force microscope, for example.

The detecting means 6a to 6d are the microprobes 2a to 2d, respectively.
The force acting between each of the microprobes 2a to 2d and the measurement target S or the displacement between each of the microprobes 2a to 2d and the measurement target S is detected, and the detection signal is detected by the piezo sensor. It is sent to the control units 5a to 5d. The detecting means 6a to 6d can detect the force or displacement acting between the microprobe and the object to be measured by detecting the change in the cantilever.
The change of the cantilever occurs according to the atomic force when the cantilever comes into contact with the material to be measured. This change in the cantilever can be detected by irradiating the back of the cantilever probe with a laser beam that has been narrowed down and detecting the reflected laser beam with a position sensitive detector (optical lever method). It is also possible to use a cantilever that can directly measure the bending amount of the cantilever probe without using it.

The piezo control units 5a-5d have a detecting means 6a.
Each microprobe 2 based on the detection signal sent from
a to 2d and the measured object S, or the displacement between each microprobe 2a to 2d and the measured object S becomes a predetermined value, with respect to each piezo element 4a to 4d The voltage to be applied is controlled individually. Since the probe control means 3 applied to the present invention can control the distance between the micro probe 2 and the measurement target S within the range of the atomic force, the micro probe 2 measures the measurement target S. It is possible to electrically detect the object S to be measured by bringing the microprobe 2 and the object S to be measured into close contact with each other to the extent that a current flows, without making an indentation on the surface.

On the other hand, the measuring means 7 comprises a constant current power source 8, a voltage measuring section 9 and an electric characteristic calculating section 10. Constant current power supply 8
Supplies a constant current to the two microprobes 2a and 2d out of the four microprobes, and the probe control means 3 causes the measured object S to be measured.
An electric current is passed through the object S to be measured through the microprobes 2a and 2d that are in contact with the surface of In addition, the voltage measuring unit 9 measures the voltage between the two microprobes 2b and 2c of the four microprobes to determine the voltage between the microprobes 2c and 2b of the measurement target S. To detect. The electrical characteristic calculation unit 10 calculates the electrical characteristic of the measurement target S using the voltage detected by the voltage measurement unit 9. The electric characteristic calculation unit 10 obtains electric characteristics such as electric resistivity and electric conductivity, and also performs measurement while changing force and displacement acting between the microprobe and the object to be measured.
It is possible to obtain the contact pressure dependence of the electrical resistivity and the electrical conductivity.

The control means 12 includes a piezo controller 5,
And the measuring means 7 (constant current power supply 8, voltage measuring section 9, electric characteristic calculating section 10) are controlled, the position control of each microprobe 2 by the probe control means 3, and the measurement by the measuring means 7 after the position control. The entire electric characteristic measuring device 1 including the operation procedure such as control is controlled.

Next, the electric characteristic measuring method of the present invention will be described with reference to the flow chart for explaining the procedure of the electric characteristic measuring method of the present invention of FIG. 2 and the schematic diagram showing the control state of the microprobe of FIG. The procedure will be described. First, the measured object S
Is set on the stage 11 included in the electrical characteristic measuring apparatus 1. The stage 11 is movable in the X-axis direction and the Y-axis direction, so that the measurement position on the measurement target S and the micro probe can be positioned in the X-axis and Y-axis directions. Further, by making the movable in the Z-axis direction, the measurement target S can be positioned in the Z-direction. Positioning in the Z-axis direction can be used not only to increase the distance from the microprobe 2 when setting the measurement target S on the stage 11 but also to perform alignment beyond the movable range of the piezo element 4. For positioning in the Z-axis direction, move the stage 11 to Z
In addition to moving in the axial direction, this can also be done by moving a supporting portion (not shown) that supports the entire piezo element 4 in the Z-axis direction.

After the object S to be measured is placed on the stage 11, the stage 11 or the supporting portion of the piezo element 4 is controlled in the Z-axis direction, and the distance between the object S to be measured and the microprobe 2 is set to the piezo element 4. Is set within a movable range and at a constant distance (FIG. 3A) (step S1). The electrical characteristic measuring apparatus 1 of the present invention is, for each of the plurality of microprobes,
After the force or displacement acting on the object S to be measured is individually controlled to bring the tip of each microprobe into contact with the surface of the object S to be measured within the range of the atomic force (step S2 below). Up to step S7), electrical characteristics are measured (step S8 below). The position control of the plurality of micro-tips can be performed simultaneously for each micro-tip, or sequentially. Steps S2 to S7 below show an example in which the position control of a plurality of microprobes is sequentially performed.

A microprobe 2 for position control is selected from a plurality of microprobes 2 (microprobes 2a to 2d in the configuration example of FIG. 1) (step S2), and a piezo supporting the selected microprobe 2 is selected. A voltage is applied to the element 4 from the corresponding piezo control section 5 (step S3), and the force or displacement applied to the microprobe 2 is detected by the detection means 6 (step S4). The piezo controller 5 fetches the detection value of the detecting means 6, compares the fetched detection value with a preset predetermined value (step S5), and applies it to the piezo element 4 in step S3 so that the detection value becomes the predetermined value. Adjust the voltage to be used. The output value of the pressure or displacement detected by the detection unit 6 increases as the microprobe 2 approaches the measurement target S, and conversely, as the microprobe 2 moves away from the measurement target S, the output of the detection unit 6 increases. The value becomes smaller. This step S
The position of the fine probe 2 is controlled by repeating 3 to step S5.

The predetermined value used for the position control of the microprobe 2 is a pressure value or displacement value that eliminates this dependency in the contact pressure dependency or displacement dependency of the electrical characteristics of the object S to be measured. Thereby, the reference value of pressure or displacement for measuring the electric characteristic value can be determined, and the measurement can be performed under uniform measurement conditions. The procedure for obtaining this reference value will be described later with reference to FIG. Piezo controller 5
Is fixed to the voltage obtained by the position control, and the position of the microprobe 2 with respect to the measured object S is determined (step S
6).

For each microprobe 2, step S2
The process of step S6 is repeated to determine the positions of all the microprobes 2. FIG. 3B schematically shows a state in which the position of each of the microprobes 2a to 2d is individually controlled according to the surface shape of the measurement target S. According to the electrical characteristic measurement of the present invention,
By individually controlling the position of each of the microprobes 2a to 2d, the microprobes 2a to 2d can be brought into contact with the microscopic surface shape of the measurement target S under the same condition, and the electric power of the microregion can be reduced. It is possible to measure the characteristics. In addition, when simultaneously performing the position control of the microprobes, the piezoelectric control units 5a to 5a.
5d controls each piezo element 4a-4d simultaneously and individually (step S7).

After the positions of all the microprobes 2 are determined, the measuring means 7 electrically detects the object S to be measured by using each microprobe 2 as a measurement terminal, and measures the electrical characteristics. For example, in the case of electrically detecting the object S to be measured by the 4-probe method using the fine probes 2a to 2d arranged in a straight line, the constant-current power source 8 can be used to select one of the four fine probes. By supplying a constant current to the two microprobes 2a, 2d,
A current is passed through the object S to be measured through 2d. Target S
The current supplied to the device flows according to the electrical characteristics of the measured object S. The voltage measuring unit 9 measures the voltage between two microprobes 2b and 2c of the four microprobes. From the measurement voltage, the current flowing between the microprobes 2c and 2b of the measurement target S and the voltage depending on the electrical characteristics are detected.

The electrical characteristic calculation unit 10 obtains the electrical characteristic of the measured object S from the obtained voltage. For example, the value ρ of the electrical resistivity of the object S to be measured is expressed by the above formula (1) when the material to be measured is sufficiently larger than the interval 1 between the microprobes and the thickness d thereof is also sufficiently large. ρ = (V / I) 2πl [Ω
・ When the material to be measured is small,
When the thickness d is thin, ρ = 4.54 in the equation (2).
It can be approximately calculated by V / dl [Ω · cm].

In addition to the above-mentioned electrical resistivity, the electrical characteristic calculation unit 10 can apply this electrical resistivity to the Wiedemann-Franz rule to obtain the thermal conductivity. By the way,
Franz's rule is that the thermal conductivity Kc of metal (due to conduction electrons)
And electrical conductivity σ (here, electrical conductivity σ is used instead of electrical resistivity ρ) is proportional to the absolute temperature, and is represented by Kc = L ₀ σT. Here, L ₀ is a constant known as Lorentz number. Further, the electrical characteristic calculation unit 10 measures the contact pressure dependency or the displacement dependency of the electrical resistivity or the thermal conductivity by changing the force or the displacement acting between the micro probe and the measurement target while changing the force. You can ask.

Next, the dependence of the electrical characteristics and the procedure for obtaining this dependence will be described with reference to the electrical characteristics diagram shown in FIG. The electrical characteristics of the object to be measured have a dependency on the contact pressure or displacement of the probe used for measurement.
Therefore, when the electrical characteristics of the measured object are measured by bringing the probe into contact with the measured object, the contact pressure of the probe or the distance between the probe and the measured object is changed as shown in FIG. If so, the measured electrical characteristics will also change.

Therefore, in order to make the measurement condition of the electric characteristic constant, the pressure value or the displacement value in which the dependence of the electric characteristic depends on the contact pressure or the displacement is used as a reference value. For example, in FIG. 4, the pressure or displacement (A in FIG. 4) at which the contact pressure dependency or displacement dependency of the electrical resistivity ρ disappears is determined, and this pressure value or displacement value is used as a reference value. Therefore, by measuring the electric characteristic using this reference value, the electric characteristic under a constant measurement condition can be obtained.

The procedure for obtaining the dependency of the electrical characteristics is performed in steps S1 to S of the flow chart shown in FIG.
By the same process as in 8, the electric characteristic at a predetermined pressure value or displacement value is measured. Next, the predetermined pressure value or displacement value in step S5 is changed, and the steps S1 to S8 are repeated again to measure the electrical characteristics at different pressure values or displacement values. By repeating the change of the predetermined pressure value or the displacement value and the measurement of the electric characteristic based on the changed predetermined value, the electric characteristic diagram showing the dependence of the electric characteristic as shown in FIG. 4 can be obtained.

In the measurement by the four-point probe method, two sets of measuring terminals each including four micro-tips are arranged in different axial directions (for example, X-axis direction and Y-axis direction). Thus, it is possible to measure the directivity of the electrical characteristics of the measured object S.

According to the embodiment of the present invention, since the fine probe can be contacted with the material to be measured by controlling the pressure within the range of the atomic force, the indentation by the fine probe on the surface of the object to be measured. It is possible to measure electrical characteristics such as electrical resistivity without giving Further, by using the probe of the scanning probe microscope as the probe, it is possible to measure in a very small area.

By applying the electrical characteristic measurement of the present invention to semiconductor manufacturing, in a semiconductor device manufacturing line,
The electrical resistivity can be directly measured using the manufacturing substrate, and since the measurement does not cause an indentation on the substrate surface, the substrate can be returned to the manufacturing process even after the measurement. Therefore, it is not necessary to use the dummy wafer for measuring the electrical resistivity, the ratio of the dummy wafer to all the silicon substrates used can be significantly reduced, and the utilization efficiency of the silicon substrate can be expected to be improved.

Further, according to the electrical characteristic measurement of the present invention, since the probe is brought into contact with the object to be measured with a force having a very small atomic force level, the surface melting layer developed in several atomic layers of the metal surface is destroyed. Without this, the surface melting process can be detected as a change in electrical resistivity. Analysis of the surface melting process can be applied to lowering the melting of materials.

Further, according to the electrical characteristic measuring apparatus of the present invention, since the drive system including the probe, the measuring system, and the control system can all be configured on one side (upper side) of the material to be measured, the state of the material to be measured can be measured. It enables high degree of freedom measurement regardless of shape and shape. For example, the sample can be placed in a crucible and the electrical resistivity of the sample can be measured while heating. In the conventional 4-probe method, when the sample is melted by heating, the probe reacts with the melted sample because the probe is strongly pressed against the sample, and it becomes impossible to measure especially the metal sample. There is a problem and even if the measurement can be continued,
The reaction chemically pollutes the sample, and it is impossible to measure the electrical resistivity of the intended substance. On the other hand, according to the electrical property measurement of the present invention, since the probe is brought into contact with the material with a very small atomic force level,
There is no significant chemical reaction between the probe and the sample,
It can be applied to measurement of electric characteristics such as electric resistivity of a liquid sample including molten metal.

The electric resistivity of the molten metal is a very important physical property value by itself, and the electric conductivity can be used to determine the value of thermal conductivity from the Wiedemann-Franz law. The value of the thermal conductivity of the molten metal is a very important physical property value as input data in the material process simulation, and it becomes easy to measure by using the electrical property measurement of the present invention, which is effective for the construction of a data base. It becomes a means.

[0046]

As described above, according to the electric characteristic measuring apparatus and the measuring method of the present invention, the electric characteristic of the object to be measured can be measured nondestructively. Further, it is possible to measure the electrical characteristics such as the electrical resistivity without giving an indentation by the probe to the surface of the material to be measured and without destroying the surface fusion layer.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining an outline of an electric characteristic measuring device of the present invention.

FIG. 2 is a flowchart for explaining the procedure of the electrical characteristic measuring method of the present invention.

FIG. 3 is a schematic diagram showing a control state of a microprobe in electric characteristic measurement of the present invention.

FIG. 4 is an electric characteristic diagram for explaining the dependence of the electric characteristics of the present invention and a procedure for obtaining the dependence.

[Explanation of symbols]

1 ... Electrical characteristic measuring device, 2, 2a-2d ... Micro probe, 3
... Probe control means 4,4a-4d ... Piezo elements 5,5
a to 5d ... Piezo controller, 6, 6a to 6d ... Detection means,
7 ... Measuring means, 8 ... Constant current power source, 9 ... Voltage measuring unit, 10
... electric characteristic calculation unit, 11 ... stage, 12 ... control means.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Rie Kojima             2-162-1202 Yutenji, Meguro-ku, Tokyo F-term (reference) 2G011 AA15 AC14 AC31 AE03                 2G028 AA04 BB11 BC01 CG02 HN11                 4M106 AA01 BA01 DD06 DH51

Claims (7)

[Claims] 1. A plurality of microprobes, probe control means capable of individually controlling each of the microprobes in at least one axial direction, displacement between each of the microprobes, and an object to be measured. The probe control means includes a detection means for detecting a force acting between the microprobe and the object to be measured, and a measurement means having at least one pair of the microprobes as measurement terminals. An electrical characteristic measuring device that controls the position of each micro probe in the uniaxial direction based on the output, and the measuring means measures the electrical characteristic of the object to be measured based on the electrical detection between the measuring terminals. 2. The measuring means measures the contact pressure dependency or the displacement dependency of the electrical characteristic based on the detected electrical characteristic and the pressure change or the displacement change detected by the detecting means.
The electrical characteristic measuring device according to claim 1. 3. The electrical characteristic measuring device according to claim 2, wherein the measuring unit obtains a reference pressure or a reference displacement for measuring the electrical characteristic based on the contact pressure dependency or the displacement dependency of the electrical characteristic. 4. The electrical characteristic measuring device according to claim 1, wherein the electrical characteristic is electrical resistivity. 5. A step of detecting a displacement between a plurality of micro-tips and an object to be measured or a force acting between each micro-tip and the object to be measured, and based on an output of the detecting means, The step of individually controlling a plurality of micro-tips to control the position in at least one axis direction, and each micro-tip as a measurement terminal, and measuring the electrical characteristics of the object to be measured based on electrical detection between the measurement terminals. A method for measuring electrical characteristics, comprising the step of: 6. The electrical characteristic measuring method according to claim 5, wherein the electrical characteristic is measured while changing the pressure or the displacement, and the contact pressure dependency or the displacement dependency of the electrical characteristic is measured. 7. The electrical characteristic measurement according to claim 6, wherein based on the contact pressure dependency or the displacement dependency of the electrical characteristic, the pressure value or the displacement value at which the dependency disappears is used as a reference value for measuring the electrical characteristic value. Method.