JP3033118B2 - Electric resistivity measurement method and 4-terminal probe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for measuring the electrical resistivity of a planar object to be measured and a four-terminal probe used in the method.

[Prior Art] Conventionally, as a method of measuring electric resistivity, a two-terminal method,
Three-terminal and four-terminal methods are known. Then, assuming that the measured current is I, the measured voltage is V, the coefficient determined from the boundary conditions is C, and the thickness of the measured object is t, the surface resistivity ρ _s and the volume resistivity ρ _v are expressed by the following equation (1). ) And (2).

ρ _s = C · (I / V) (1) ρ _v = C · t (I / V) (2) As a two-terminal method, the outer shape of the device under test S is defined as the boundary condition of the current path. The method shown in FIG. 25A and the method shown in FIG. 25B using the shape of the electrode as a boundary condition are known. Where I
Is a constant current power supply, and V is a voltmeter. However, in such a method, since the current terminal and the voltage terminal are common as shown by the hatched portions in the figure, the resistance of the DUT including (contact resistance + lead resistance) is measured. Therefore, the two-terminal method has been adopted as a measuring method in the case of high-resistance measurement or simple measurement in which (contact resistance + lead wire resistance) can be ignored.

The four-terminal method is basically a method in which the external shape of a rectangular DUT is used as a boundary condition of a current path as shown in FIG. 25 (c), and an accurate measurement of resistivity is possible in principle.

As a kind of the four-terminal method, as shown in FIG.
There is a four-probe method in which four probes are arranged in a line, and two outer probes are used as current terminals, and two inner probes are used as voltage terminals. Is known as a practical measurement method. Here, in the case of a planar object to be measured having an infinitely wide and uniform resistivity ρ, the coefficient C in the above equations (1) and (2) is given by a constant determined by the probe.

[Problems to be Solved by the Invention] The present invention is to solve the problems in the four-terminal method, and the problems are listed as follows.

Problems of Voltage Terminals The probe used as a voltage terminal actually used is not an ideal point contact (contact area = 0), and therefore, when placed on a current path, a current i as shown in FIG. 26 flows. As a result, the current lines of force are disturbed, causing a measurement error. In particular, an error increases when measuring an object to be measured having a high resistance.

Boundary condition problem When the boundary conditions that determine the current path depend on the external shape, dimensions, measurement position, etc. of the DUT, it is assumed that the entire DUT has a uniform resistivity ρ. It cannot be used for an object whose resistivity greatly fluctuates inside the object. Further, since the boundary condition changes every time the measurement is performed, a complicated multivariable calculation for calculating the correction coefficient every time the measurement is performed must be performed.

Problem of breakage of DUT by measuring terminal When using a probe, the contact pressure with the DUT is large,
The device under test may be damaged.

[Means for Solving the Problems] In a first mode of the electric resistivity measuring method of the present invention, two current terminals and two voltage terminals are separated from each other and brought into contact with an object to be measured. In a method for measuring an electric resistivity of an object to be measured based on a voltage between the two voltage terminals when a constant current flows between current terminals, one of the two current terminals is Contacting the device under test so as to continuously or intermittently surround a first predetermined region on the device under test, and the other of the two current terminals is connected to a first predetermined region on the device under test Second containing
Is contacted with the device under test so as to continuously or intermittently surround a predetermined region of the device, and one of the two voltage terminals is connected to the first
And the other of the two voltage terminals is brought into contact with an area outside the second predetermined area.

In a second mode of the method for measuring electric resistivity according to the present invention, two current terminals and two voltage terminals are separated from each other and brought into contact with an object to be measured, and a constant current flows between the two current terminals. In the electric resistivity measuring method for measuring the electric resistivity of the device under test based on the voltage between the two voltage terminals at the time, one of the two current terminals is connected to a first terminal on the device under test. Is contacted with the device under test so as to continuously or intermittently surround a predetermined region of the device, and the other of the two current terminals is connected to a second region including a first predetermined region on the device under test.
Contacting the object to be measured so as to surround the predetermined region, one of the two voltage terminals is brought into contact with the first predetermined region, and the other of the two voltage terminals is brought into the second predetermined region. And contacting a position near the other current terminal.

According to a third embodiment of the electric resistivity measuring method of the present invention, two current terminals and two voltage terminals are separated from each other and brought into contact with an object to be measured, and a constant current is applied between the two current terminals. In the electric resistivity measuring method for measuring the electric resistivity of the device under test based on the voltage between the two voltage terminals at the time, one of the two current terminals is connected to a first terminal on the device under test. Is contacted with the device under test so as to continuously or intermittently surround a predetermined region of the device under test, and the other of the two current terminals forms a second predetermined region on the device under test that does not include the first predetermined region. The device is brought into contact with the object to be measured continuously or intermittently, one of the two voltage terminals is brought into contact with the first predetermined region, and the other of the two voltage terminals is brought into the second predetermined region. It is characterized by contacting inside.

In the first embodiment of the four-terminal probe for measuring electrical resistivity of the present invention, two current terminals and two voltage terminals are arranged insulated from each other such that each of the two terminals is separated from each other and contacts an object to be measured. In the four-terminal probe for measuring electrical resistivity, one of the two current terminals is disposed so as to continuously or intermittently surround the outside of one of the two voltage terminals, and the two current terminals are connected to each other. The other is arranged to surround the outside of the one current terminal continuously or intermittently, and the other of the two voltage terminals is arranged outside the other current terminal.

In a second embodiment of the four-terminal probe for measuring electrical resistivity according to the present invention, two current terminals and two voltage terminals are arranged insulated from each other so that the two current terminals and the two voltage terminals are separated from each other and contact the object to be measured. In the four-terminal probe for measuring electrical resistivity, one of the two current terminals is disposed so as to continuously or intermittently surround the outside of one of the two voltage terminals, and the two current terminals are connected to each other. The other is arranged so as to continuously or intermittently surround the outside of the one current terminal, and the other of the two voltage terminals is arranged near the inside of the other current terminal.

A third embodiment of the four-terminal probe for measuring electrical resistivity according to the present invention is arranged so that two current terminals and two voltage terminals are insulated from each other so that they are separated from each other and come into contact with an object to be measured. In the four-terminal probe for measuring electrical resistivity, one of the two current terminals is disposed so as to continuously or intermittently surround the outside of one of the two voltage terminals, and the two current terminals are connected to each other. The other is arranged so as to continuously or intermittently surround the outside of the other of the two voltage terminals.

[Operation] In one embodiment of the electric resistivity measuring method of the present invention, two circular closed curved current terminals are arranged on an object to be measured, and at least one of the two voltage terminals is connected to the current terminal. Place inside. Then, a constant current is caused to flow between the current terminals, and the electrical resistivity of the device under test is measured from the voltage between the voltage terminals and the radius and arrangement of the two current terminals. In such a measurement, the voltage terminal is located within the region inside the current terminal that has the same potential, and no current that disturbs the current line of force flows through the voltage terminal. As a result, accurate measurement can be performed.

For example, a large circular closed current terminal is disposed outside a small circular closed current terminal, one voltage terminal is disposed inside the small current terminal, and the other voltage terminal is disposed outside the small current terminal. In the case of the configuration in which the small current terminals are arranged in the central portion of the large current terminals, that is, the small current terminals arranged in the portion where the current density is high, the inner region is made equal in voltage, and one of the voltage terminals arranged in the inner region is Is removed from the current path having the high current density, and no current that disturbs the current line flows through the voltage terminal. Further, in this case, since the current path boundary condition is determined only by the size of the two current terminals, regardless of the shape, dimensions, measurement position, and the like of the device under test, Using the coefficient as a constant, the resistivity can be easily measured.

Further, for example, in a case where two current terminals having a circular closed curve are arranged at a predetermined distance from each other, and a voltage terminal is arranged inside each current terminal, an inner region of each current terminal forming a closed curve is equal. It becomes a potential, and the voltage terminals are located in the respective equipotential regions, and no current that disturbs the current line of force flows through the voltage terminals.

On the other hand, in one embodiment of the four-terminal probe for measuring electric resistivity of the present invention, by forming two current terminals in a circular closed curve shape, the contact surface with the object to be measured is enlarged to increase the contact resistance. To achieve the uniformity of Further, the contact pressure with the object to be measured is made smaller than that in the case of the probe, so that there is no possibility of damaging the object to be measured.

Further, for example, by dividing a portion of the current terminal formed into a circular closed curve into equal parts, the nonuniformity of the contact resistance as a whole of the current terminal is compensated.

Example FIGS. 1 to 10 show different examples belonging to the first embodiment of the measuring method according to the present invention, respectively. FIGS. 11 to 19 show four terminals according to the present invention, respectively. FIG. 20 shows a different embodiment belonging to the first embodiment of the probe, FIG. 20 shows an embodiment belonging to the second embodiment of the measuring method according to the present invention, and FIG. 21 to FIG. Fig. 4 shows a different embodiment belonging to the third embodiment of the four-terminal probe according to the invention.

Therefore, in the following, "the measuring method of the first embodiment", "the four-terminal probe of the first embodiment", "the four-terminal probe of the second embodiment", "the measuring method of the second embodiment" , And the "four-terminal probe of the third embodiment" will be described with reference to the corresponding drawings.

"About the measuring method of the first embodiment" First, a description will be given based on the example of FIG.

In the figure, reference numerals 1 and 2 denote current terminals, and a portion in contact with an object to be measured is formed into two large and small circular closed curves having different sizes. 3 and 4 are voltage terminals.
When performing the measurement, first, the current terminals 1 and 2 are arranged on the object to be measured. At this time, the smaller current terminal (hereinafter referred to as “small diameter current terminal”) 1 is arranged concentrically and insulated from the inside of the larger current terminal (hereinafter referred to as “large diameter current terminal”) 2. Further, one voltage terminal 3 is insulated and arranged inside the small-diameter current terminal 1, and the other voltage terminal 4
Are insulated and arranged outside the large-diameter current terminal 2. And
A constant current is supplied between the current terminals 1 and 2 by a constant current power supply 5, and a voltage between the voltage terminals 3 and 4 is measured by a voltmeter 6.

In such an embodiment, since the boundary condition of the current path is determined only by the size of the two current terminals 1 and 2, the above-mentioned equation ( The coefficient C of 1) and (2) will be given as a constant. Further, since the current terminals 1 and 2 form a closed curve, the two regions where the voltage terminals 3 and 4 are arranged, that is, the inner region of the small-diameter current terminal 1 and the outer region of the large-diameter current terminal 2, It becomes equipotential within the region. Therefore, the radius of the large diameter current terminal 2 is
Assuming that r ₁ and the radius of the small-diameter current terminal 1 are r ₂ , when the thickness t of the DUT is sufficiently smaller than the radii r ₁ and r ₂ , the surface resistivity ρ _s and the volume resistivity ρ _v is obtained by the following equations (3) and (4).

ρ _s = {2π / l _n (r ₁ / r ₂ )} · (V / I) (3) ρ _v = {2π · t / l _n (r ₁ / r ₂ )} · (V / I) (4) By the way, since the two regions where the voltage terminals 3 and 4 are arranged have the same voltage as described above, the voltage terminals 3 and 4 have the second terminal which causes a measurement error.
The current i as described in FIG. 26 does not flow. Also,
Since the shapes, dimensions, and positions of the voltage terminals 3 and 4 do not depend on the principle, the contact area between the voltage terminals 3 and 4 and the object to be measured is increased to reduce the contact resistance, and the input current of the voltage measuring device is reduced. Errors can be reduced. Therefore, it is possible to measure an object to be measured having a wider resistance value width. Furthermore, since the contact pressure with the object to be measured is lower than in the case of the probe,
The possibility of damaging the device under test is also reduced. In addition, since the small-diameter current terminal 1 is formed in a circular closed curve, the circumference thereof is longer than that of the case of a probe, and an accurate average value of the resistivity within the boundary condition can be measured. In addition, the influence of the non-linear phenomenon can be reduced, and the resistance of the constant current power supply 5 can be reduced because the measured resistance value decreases.

Next, based on the embodiment of FIG.
The main differences between the embodiments of the measuring method shown in FIGS. 9 to 9 will be described.

In the case of the example shown in FIG. 2, the voltage terminal (hereinafter referred to as “outer voltage terminal”) 4 arranged outside the large-diameter current terminal 2 is deformed, and the portion that comes into contact with the object to be measured is formed as a circular closed curve. It is arranged concentrically insulated outside the radial current terminal 2.

In the case of the example shown in FIG. 3, a hole _2a is made in _a contact portion of the large diameter current terminal 2 with the object to be measured, and the outer voltage terminal 4 is insulated through the hole _2a .

In the case of the example of FIG. 4, the outer voltage terminal 4 is insulated and disposed near the inner side of the large-diameter current terminal 2. In the case of this example, although the outer voltage terminal 4 is located on the current path, the current radially flowing from the small-diameter current terminal 1 is located near the large-diameter current terminal 2 where the current density is low. The adverse effect of the current i described above is extremely small. Rather than this, the voltage terminal 3 (hereinafter referred to as “inside voltage terminal”) disposed inside the small-diameter current terminal 1 should not be disposed in a current path having a high current density. The effect avoidance is greater.

In the case of the example of FIG. 5, the large-diameter current terminal 2 in the example of FIG. 2 is equally divided into a plurality of parts (six in the figure) to be insulated from each other, and the divided terminals 2-1,. are connected to a common constant-current power supply 5 to 6 respectively through equal resistors R _1. Resistor R ₁ is the measurement object and the terminal 2-1, sufficiently larger than the contact resistance between the ...... 2-6. Therefore, the resistance value as viewed from the constant current power supply 5 is equal to the value of each terminal 2-1,.
And the current is equally divided to compensate for the non-uniform contact resistance of the large-diameter current terminal 2 as a whole.

In the case of the example of FIG. 6, the small-diameter current terminal 1 in the example of FIG. 5 is divided and insulated from each other similarly to the large-diameter current terminal 2, and each of the divided terminals 1-1,. Equal resistance R ₂
To the common constant current power supply 5. Its resistance
R ₂ is similarly compensate for unevenness in the contact resistance of the entire small current terminal 1 and the resistor R _1.

In the case of the example of FIG. 7, a plurality of sets of the terminals 1, 2, 3, and 4 of the example of FIG. And the voltmeter 6 are selectively connected, and the resistivity of each part of the device under test S is measured. As a result, the DUT S whose resistivity greatly fluctuates inside
In contrast, the resistivity of each part can be measured accurately and at high speed. Even when a large number of terminals 1, 2, 3 and 4 are arranged close to each other, mutual interference does not occur unless they are connected to the constant current power supply 5 or the voltmeter 6.

In the case of the example of FIG. 8, two sets of current terminals 1 and 2 are arranged close to each other, and voltage terminals 3 and 4 are arranged inside the small-diameter current terminals 1 and 1, respectively. Then, separate constant current power supplies 5 are connected to the two sets of current terminals 1 and 2, and constant currents in the same direction or opposite directions are applied to the two sets of current terminals 1 and 2, thereby setting the voltage terminals 3 and 4. Measure the voltage between them. When a constant current in the opposite direction is applied to both sides, the average of the resistivity ρ in each region can be measured, and a constant current in the same direction (the direction from the small-diameter current terminal 1 to the large-diameter current terminal 2) can be measured. When flowing, the resistivity ρ in each region
Can be measured.

In the case of the example of FIG. 9, a plurality of sets of the terminals 1, 2, 3 and 4 of the example of FIG. 8 are arranged on the object to be measured. A common voltmeter 6 is selectively connected between the adjacent voltage terminals 3 and 4, and between the current terminals 1 and 2 surrounding one of the voltage terminals 3 and 4, and between the current terminals 1 and 2 surrounding the other. The constant current power supply 5 is connected to each of the terminals 2 and 2, and the average or difference in the resistivity between the respective parts of the device under test is measured as in the case of FIG.

In the case of FIG. 10, the two large-diameter current terminals 2 in the example of FIG. 8 are shared, and the size of one common large-diameter current terminal 2 is the same as that of the two small-diameter current terminals 1. It has a large diameter surrounding the location. When performing the measurement, the large-diameter current terminal 2 is placed on the object to be measured, and the two small-diameter current terminals 1 are positioned at target positions on a radial line passing through the center of the large-diameter current terminal 2. Surround them. Then, constant current power supplies 5-1 and 5-2 are connected between one small diameter current terminal 1 and the large diameter current terminal 2 and between the other small diameter current terminal 1 and the large diameter current terminal 2, respectively. . And
By the constant current power supplies 5-1 and 5-2, currents in opposite directions are applied to the two small diameter current terminals 1 using the large diameter current terminal 2 as a common electrode.

Therefore, in the case of the present embodiment, it is possible to measure the electrical resistivity of the device under test in the region inside the large-diameter current terminal 2. That is, the boundary condition of the measurement site is determined by the large-diameter current terminal 2, and the shape and size of the object to be measured have no influence. For this reason, for example, a plurality of combinations of terminals 1, 2, 3, and 4 having a pattern as shown in FIG. 10 are arranged on an object to be measured, and the resistivity of the object to be measured at each of the arranged portions is simultaneously measured. It is also possible.

“About the Four-Terminal Probe of the First Embodiment” First, the four-terminal probe of FIG. 11 (hereinafter simply referred to as “probe”) will be described as a basic form.

The probe shown in FIG. 11 (a) is for carrying out the measuring method described with reference to FIG. 2 above. The current terminals 1 and 2 and the voltage terminals 3 and 4 are embedded in an insulating probe body 7. The configuration is as follows. Inside voltage terminal 3
Is a round rod shape, the small diameter current terminal 1 is a straight cylindrical shape, the large diameter current terminal 2 and the outer voltage terminal 4 are stepped cylindrical shapes, and when viewed from the bottom of the probe body 7, the terminals 1, 2,. The tips of 3 and 4, that is, the portions in contact with the object to be measured, form the arrangement pattern of FIG.

The probe thus configured has the terminals 1, 2, 3 and 4 in contact with the object to be measured, the constant terminals 5 connected to the base terminals of the current terminals 1 and 2, and the voltage terminals 3 and The voltmeter 6 is connected to the proximal end of 4 to be used.

In the case of the example of FIG. 11 (b), the probe body 7 of FIG. 11 (a) is provided inside the case 8, a spring 9 is interposed therebetween, and the probe body A configuration is adopted in which a pressurized conductive sheet 10 covering the tip of 7 is attached. The sheet 10 is formed of a pressurized conductive rubber-like substance that exhibits a substantially constant resistance value when the pressing force is increased. For example, JSR PC manufactured by Japan Synthetic Rubber Co., Ltd.
R 305-02 can be used.

When using, hold the case 8 and press the probe body 7 against the object to be measured via the spring 9 so that the terminals 1, 2, 3
The sheet 10 is pressurized between the tip of the and 4 and the object to be measured. Then, the pressurized portion of the sheet 10 electrically connects the tips of the terminals 1, 2, 3, and 4 and the object to be measured. Thereby, it is used similarly to the case of the example of FIG. 11 (a). When the sheet 10 is sufficiently pressurized, the contact resistance between the terminals 1, 2, 3, and 4 and the object to be measured is made uniform, and the object to be measured is prevented from being damaged.

In the case of the examples shown in FIGS. 12 and 13, terminals 1, 2, 3 and 4 made of a pressurized conductive rubber-like substance or a conductive rubber-like substance are formed in a probe main body 11 made of an insulating rubber-like substance. doing. The terminals 1, 2, 3 and 4 are formed in the arrangement pattern of FIG. 2 described above, and the other terminals 1, 2 and 4 are formed in a circular closed curve with the inner voltage terminal 3 as the center. The terminals 1, 2, 3 and 4 are exposed on the upper and lower surfaces of the probe main body 11, respectively.

In use, the probe main body 11 and the wiring board 12 are placed on the object S to be measured and pressurized. A wiring pattern for connecting a constant current power supply 5 between the current terminals 1 and 2 and for wiring a voltmeter 6 between the voltage terminals 3 and 4 is formed on the wiring board 12 as shown in FIG. The terminals 1, 2, 3 and 4 are in contact with the device under test S and are connected to a constant current power supply 5 and a voltmeter 6. Thus, it is used similarly to the case of the example of FIG. Note that the exposed portions of the terminals 1, 2, 3 and 4 on the lower surface side of the lobe main body 11 may be formed so as to be recessed one step below the lower surface of the probe main body 11 located therearound. The terminals 1, 2, 3, and 4 come into contact with the object S under the condition that the main body 11 is pressed.

In the case of the example of FIG. 14, a collective probe having a configuration in which a plurality of probe bodies 7 of the example of FIG. Therefore, the present invention can be applied to the above-described measurement method shown in FIG. 7 or FIG. In FIG. 14, some of the plurality of probe bodies 7 arranged at equal intervals in the vertical and horizontal directions are partially omitted.

FIG. 15 shows an example of using the collective probe of the example of FIG. 14 described above, in which a sheet 10 of a pressurized conductive rubber-like substance is interposed between the probe and the measured object S. is there.
In the case of this example, the sheet 10 is pressurized, and the terminals 1, 2, 3, and 4 are connected to the DUT via the sheet 10.

In the case of the examples of FIGS. 16 and 17, the probes of the examples of FIGS. 12 and 13 described above are grouped, and the grouped probes are incorporated in a measuring apparatus. The collective probe of this example has a probe body 11 made of an insulating rubber-like substance and a twelfth probe body.
A plurality of sets of terminals 1, 2, 3 and 4 in FIG. 13 and FIG. 13 are formed. In addition, a matrix switch and a wiring board (both not shown) are incorporated into the wiring board 12 according to the number of the formed wiring boards. The matrix switch is connected to a common constant current power supply 5 and a voltmeter 6 with terminals 1, 2, 3 for each set of probes.
And 4 are selectively connected. And
The wiring board 12 and the probe body 11 are provided in a case 14 of the measuring device.

In use, the object S is placed on the probe body 11, the insulating rubber-like sheet 15 is further placed, and the lid 16 is closed. Then, the inside of the case 14 is evacuated to a vacuum,
Is brought into close contact with the probe main body 11, and each set of probes is selectively connected to the constant current power supply 5 and the voltmeter 6 by the matrix switch, thereby implementing the measurement method described with reference to FIG. Can be offered.
By setting the terminals 1, 2, 3 and 4 in the probe body 11 to the arrangement pattern shown in FIG.
The measuring method described with reference to the figures can also be implemented.

In the case of the example shown in FIG. 18, an apparatus for measuring the potential at the moving position while appropriately moving the outer voltage terminal 4 by applying the measuring method shown in FIG. 4 described above. In the figure, reference numeral 17 denotes a coaxial probe, which has a small-diameter current terminal 1 and an inner voltage terminal 3 having an arrangement pattern as shown in FIG. The base end of the coaxial probe 17 is fixed at a fixed position of the apparatus main body 18, and the distal end thereof is
It is in contact with the center of the disk-shaped DUT set above. A large-diameter current terminal 2 is connected to the outer periphery of the device under test S, and an outer voltage terminal (probe) 4 is connected to a slide body 19 provided in the apparatus main body 18 in the X-axis direction. It is slidably mounted on.

In use, a constant current power supply 5 is connected between the current terminals 1 and 2, and a voltmeter 6 is connected between the voltage terminals 3 and 4.
Is connected, and the outer voltage terminal 4 is brought into contact with an arbitrary position on the DUT S, and the voltage at that time is measured. By repeating this, the potential distribution at many positions on the device under test S is obtained.

FIG. 19 is an explanatory diagram of another configuration example of the same device as in FIG. In the case of the present example, the left and right rotation of the disk-shaped device S such as a silicon wafer set on the rotary table 20 and the radial sliding of the outer voltage terminal (probe) 4 cause the outer voltage terminal 4 to move. Can be connected to any position on the DUT S. In the figure, reference numeral 21 denotes a stage, which holds the coaxial probe 17 so as to be in contact with the center of the device under test S, and connects the outer voltage terminal 4 to the rotary table.
It is provided so that it can slide along 20 radial directions. A large-diameter current terminal 2 is connected to the periphery of the device under test S.
When performing the measurement, the constant current power supply 5 and the voltmeter 6 are connected as in the case of FIG.

The terminals 1, 2, 3 and 4 are arranged on the probe body so as to form the above-mentioned arrangement pattern in FIG. 10, or the terminals 1, 2, 3 and 4 forming the pattern in FIG.
An assembly probe in which a plurality of sets 3 and 4 are arranged may be configured. By using a plurality of the former probes or using the latter collective probe, it is possible to simultaneously measure the resistivity in a large number of portions of the measured object.

"About the four-terminal probe of the second embodiment" The four-terminal probe of this embodiment is shown in FIGS.
The measuring method described with reference to the figure, that is, a measuring method for compensating for nonuniformity of contact resistance by equally dividing one or both of the current terminals 1 and 2 into a circular closed curve. It is for implementing.
The configuration is such that at least one of the current terminals 1 and 2 in the four-terminal probe of the first embodiment described above is equally divided into a plurality.

"About the measuring method of the second embodiment" FIG. 20 is a diagram for explaining a first example of the measuring method of the second embodiment according to the present invention.

In the case of the present embodiment, the portions of the current terminals 1 and 2 that come into contact with the object to be measured are formed in a circular closed-curve shape having a size that can be arranged separately on the object to be measured. Voltage terminals 3 and 4 are sized to be located inside current terminals 1 and 2. When performing the measurement, first, the current terminals 1 and 2 are arranged above the device under test by a predetermined distance. Further, the voltage terminals 3 and 4 are insulated and arranged inside the current terminals 1 and 2 (the center part in the present embodiment). Then, a constant current flows between the current terminals 1 and 2 by the constant current power supply 5, and the voltage between the voltage terminals 3 and 4 is measured by the voltmeter 6.

In such an embodiment, since the portions of the current terminals 1 and 2 that make contact with the device under test form a closed curve, the region where the voltage terminals 3 and 4 are arranged, that is, the region inside the current terminal 1 and the current terminal The inner regions of 2 have the same potential in each region. Therefore, when the current terminals 1 and 2 having a radius r are arranged at a distance 2d between the terminals on an infinitely-planar DUT having a uniform resistivity, and a current of + I and -I flows through each of the terminals, an electromagnetic A rudimentary study of chemistry leads to the formation of equipotential lines known as the Apollonium circles. By utilizing this property, the voltage V between the voltage terminals 3 and 4 is given by the following equation (5). δs is the surface resistivity.

V = δs / π · ln [｛d + (d ² −r ² ) ^1/2 ｝ / r] · I (5) Here, if the thickness of the object to be measured is t, the surface resistivity δs
And the volume resistivity δ _v are determined by the following equations (6) and (7).

δ _s = π / ln [｛d + (d ² + r ² ) ^1/2 ｝ / r] · (V / I) (6) δ _v = πt / ln [｛d + (d ² + r ² ) ^1/2 ｝ / R] · (V / I) (7) By the way, since the two regions where the voltage terminals 3 and 4 are arranged have the same voltage as described above, the voltage terminals 3 and 4 have: Cause the measurement error
The current i as described in FIG. 26 does not flow. Also,
Since the shapes, dimensions, and positions of the voltage terminals 3 and 4 do not depend on the principle, the contact area between the voltage terminals 3 and 4 and the object to be measured is increased to reduce the contact resistance, and the input current of the voltage measuring device is reduced. Errors can be reduced. Therefore, it is possible to measure an object to be measured having a wider resistance value width. Furthermore, since the contact pressure with the object to be measured is lower than in the case of the probe,
The possibility of damaging the device under test is also reduced.

"About the four-terminal probe of the third embodiment" Figs. 21 (a) and (b) are diagrams for explaining the first example of the four-terminal probe of the third embodiment.

The probe shown in the figure is for implementing the measuring method described with reference to FIG. 20, and has a configuration in which current terminals 1 and 2 and voltage terminals 3 and 4 are embedded in an insulating probe body 23. The current terminals 1 and 2 have a cylindrical shape, and the voltage terminals 3 and 4 have a round bar shape. In FIG. The parts in contact with are in the arrangement pattern of FIG. At the tip of the probe body 23, the vicinity of the tips of the terminals 1, 2, 3 and 4 is recessed one step lower.

The probe thus configured has the terminals 1, 2, 3 and 4 in contact with the object to be measured, the constant terminals 5 connected to the base terminals of the current terminals 1 and 2, and the voltage terminals 3 and The voltmeter 6 is connected to the proximal end of 4 to be used.

 FIG. 22 is a diagram for explaining the second embodiment.

The probe of this example has a probe body 23 described with reference to FIG.
25, and a sheet 26 of a pressurized conductive rubber-like substance that covers the tip of the probe body 23 is attached to the tip of the case 24. The sheet 26 shows a substantially constant resistance value when the pressing force is increased, similarly to the sheet 10 described with reference to FIG. 11 (b).

When using, hold the case 24, press the probe body 23 against the DUT via the spring 25, and connect the terminals 1, 2, 3
The sheet 26 is pressurized between the tip of the and 4 and the object to be measured. Then, the pressurized sheet 26 electrically connects the tips of the terminals 1, 2, 3 and 4 to the object to be measured. Thereby, it is used similarly to the case of the example of FIG. The sheet 26 is sufficiently pressurized so that the terminals 1, 2,
In addition to making the contact resistance between 3 and 4 and the DUT uniform, it also prevents loss of the DUT.

FIG. 23 and FIG. 24 are diagrams for explaining the third embodiment.

The probe of this example is a probe body made of an insulating rubber-like substance.
27, terminals 1, 2, 3, and 4 made of a pressurized conductive rubber-like substance or a conductive rubber-like substance are formed. Terminal 1,
20, 3 and 4 are formed in the above-described arrangement pattern of FIG. 20, and the current terminals 1 and 2 are formed in a circular closed curve shape with the voltage terminals 3 and 4 as centers. The terminals 1, 2, 3 and 4 are exposed on the upper and lower surfaces of the probe main body 27.

In use, the probe body 27 and the wiring board 28 are placed on the object S as shown in FIG. Wiring board
28, a constant current power supply 5 is connected between the current terminals 1 and 2 as shown in FIG.
The wiring pattern for wiring
1, 2, 3 and 4 are in contact with the device under test S and connected to a constant current power supply 5 and a voltmeter 6. In this way, the 21st
It is used as in the case of the example in the figure. The exposed portions of the terminals 1, 2, 3 and 4 on the lower surface side of the probe main body 27 may be formed so as to be recessed one step from the lower surface of the probe main body 12 located therearound. The terminals 1, 2, 3, and 4 come into contact with the object S under the condition that the main body 27 is pressed.

[Effects of the Invention] As described above, in the first embodiment of the electric resistivity measuring method of the present invention, one current terminal is connected to the device under test so as to surround the first predetermined region on the device under test. The other current terminal is brought into contact with the device under test so as to surround a second predetermined region including the first predetermined region, one voltage terminal is brought into contact with the first predetermined region, and the other voltage terminal is brought into contact with the device under test. By contacting the terminals with the region outside the second predetermined region, one and the other of the voltage terminals can be brought into contact with each other in the equipotential region, so that the respective voltage terminals disturb the current lines of force. An accurate measurement of the electrical resistivity can be performed without generating a large current. Further, the other voltage terminal may be brought into contact with a position near the other current terminal in the second predetermined region as in the second embodiment of the present invention. Although located on the current path, the current density in the current path is small, so that accurate measurement of the electrical resistivity can be similarly performed.

For example, a large circular closed current terminal is disposed outside a small circular closed current terminal, one voltage terminal is disposed inside the small current terminal, and the other voltage terminal is disposed outside the small current terminal. In the case of the arranged form, the central part of the large current terminal, that is, the small current terminal arranged in the portion where the current density is high, makes its inner region an equal voltage, and the one voltage terminal arranged in the inner region is It is removed from the current path with the high current density, and accurate measurement can be performed without flowing a current that disturbs the current line of force at the voltage terminal. In addition, in this case, since the current path boundary condition is determined only by the size of the two current terminals, regardless of the shape, dimensions, measurement position, and the like of the DUT, the resistivity calculation formula Using the coefficient as a constant, the resistivity can be easily obtained.

Further, a third embodiment of the method for measuring electric resistivity of the present invention is as follows.
One current terminal is brought into contact with the device under test so as to surround a first predetermined region on the device under test, and the other current terminal is connected so as to surround a second predetermined region not including the first predetermined region. One of the voltage terminals is brought into contact with the device under test, one of the voltage terminals is brought into contact with the first predetermined region, and the other of the voltage terminals is brought into contact with the second predetermined region. The contact can be made within the region, and as a result, an accurate measurement of the electric resistivity can be performed without causing a current that disturbs the current line of force at each voltage terminal.

For example, in the case where two current terminals having a circular closed curve are arranged at a predetermined distance from each other and voltage terminals are arranged inside the respective current terminals, an inner region of each current terminal forming a closed curve becomes equipotential. Since the voltage terminals are located in the respective equipotential regions, accurate measurement can be performed without flowing a current that disturbs the current line of force through the voltage terminals.

On the other hand, in the first embodiment of the four-terminal probe for measuring electric resistivity of the present invention, one current terminal is arranged so as to surround the outside of one voltage terminal, and the other current terminal is arranged outside the one current terminal. By arranging them so as to surround them, and arranging the other voltage terminal outside the other current terminal, when the current terminal and the voltage terminal are brought into contact with the device under test, one and the other of the voltage terminals are respectively connected. It can be located in the equipotential region, and as a result, an accurate measurement of the electric resistivity can be performed without generating a current that disturbs the current line of force at each voltage terminal. Further, the other voltage terminal may be arranged near the inside of the other current terminal as in the second embodiment of the present invention. In this case, although the other voltage terminal is located on the current path, Since the current density in the current path is small, accurate measurement of the electrical resistivity can be similarly performed.

In the third embodiment of the four-terminal probe for measuring electric resistivity of the present invention, one current terminal is arranged so as to surround one voltage terminal, and the other current terminal is arranged so as to surround the other voltage terminal. By doing so, when the current terminal and the voltage terminal are brought into contact with the device under test, one and the other of the voltage terminals can be positioned in the equipotential region, and as a result, each of the voltage terminals Accurate measurement of electric resistivity can be performed without generating a current that disturbs the current line of force.

In addition, since the current terminal contacts the DUT so as to surround the voltage terminal, the contact surface between the current terminal and the DUT can be increased, and the contact pressure between them can be reduced accordingly, and the DUT can be measured. Object damage can be avoided.

Further, by equally dividing the portion of the current terminal that is formed into a circular closed curve, it is possible to compensate for nonuniform contact resistance of the current terminal as a whole.

[Brief description of the drawings]

FIG. 1 to FIG. 10 are schematic plan views for explaining different examples belonging to the first embodiment of the electric resistivity measuring method according to the present invention, and FIG. 11 to FIG. FIG. 20 is a view for explaining a different embodiment belonging to the first embodiment of the four-terminal probe according to the present invention. FIG. 20 is an embodiment belonging to the second embodiment of the electric resistivity measuring method according to the present invention. 21 to 24 are schematic plan views for explaining the third embodiment of the four-terminal probe according to the present invention.
FIG. 25 is a view for explaining an example belonging to the embodiment of FIG. 25, FIG. 25 is an explanatory view of a different example of the conventional electric resistance measuring method, and FIG. 26 is an enlarged view of a tip of a voltage terminal placed on a current path. FIG. 1,2 ... current terminal, 3,4 ... voltage terminal, 5 ... constant current power supply, 6 ... voltmeter, 7,23,27 ... probe body, S ... DUT.

Claims (12)

(57) [Claims] 1. A voltage between two voltage terminals when two current terminals and two voltage terminals are separated from each other and brought into contact with an object to be measured, and a constant current flows between the two current terminals. A method for measuring the electrical resistivity of the device under test, based on the one of the two current terminals, continuously or intermittently in a first predetermined region on the device under test The other of the two current terminals is continuously or intermittently surrounded by a second predetermined area including the first predetermined area on the object to be measured. One of the two voltage terminals is brought into contact with the first predetermined region, and the other of the two voltage terminals is brought into contact with an outer region of the second predetermined region. How to measure electrical resistivity. 2. The electrical resistivity according to claim 1, wherein the other voltage terminal is brought into contact with the object to be measured in a circular closed curve so as to annularly surround the outside of the other current terminal. Measurement method. 3. A voltage between the two voltage terminals when a constant current is applied between the two current terminals and the two voltage terminals when the two current terminals and the two voltage terminals are separated from each other and brought into contact with an object to be measured. A method for measuring the electrical resistivity of the device under test, based on the one of the two current terminals, continuously or intermittently in a first predetermined region on the device under test The other of the two current terminals is brought into contact with the device under test to surround a second predetermined region including the first predetermined region on the device under test, One of the two voltage terminals is brought into contact with the first predetermined region, and the other of the two voltage terminals is brought into contact with a position near the other current terminal in the second predetermined region. Method for measuring electrical resistivity. 4. The one current terminal is brought into contact with the device under test in a circular closed curve so as to surround the first predetermined region, and the other current terminal is formed so as to surround the second predetermined region. The method for measuring electric resistivity according to claim 1 or 3, wherein the object is brought into contact with the object to be measured in a circular closed curve shape. 5. A voltage between two voltage terminals when a constant current flows between the two current terminals when the two current terminals and the two voltage terminals are separated from each other and brought into contact with an object to be measured. A method for measuring the electrical resistivity of the device under test, based on the one of the two current terminals, continuously or intermittently in a first predetermined region on the device under test The other of the two current terminals is continuously or intermittently surrounded by a second predetermined region not including the first predetermined region on the DUT. An electrical device, wherein one of the two voltage terminals is brought into contact with the first predetermined region, and the other of the two voltage terminals is brought into contact with the second predetermined region. How to measure resistivity. 6. The one current terminal is brought into contact with the device under test in a circular closed curve shape so as to surround the first predetermined region, and the other current terminal is formed so as to surround the second predetermined region. The method for measuring electric resistivity according to claim 5, wherein the object to be measured is brought into contact with the object in a circular closed curve shape. 7. A four-terminal probe for measuring electrical resistivity, wherein two current terminals and two voltage terminals are spaced apart from each other and in contact with an object to be measured so that they are insulated from each other. One of the two current terminals is disposed so as to continuously or intermittently surround the outside of one of the two voltage terminals, and the other of the two current terminals continuously surrounds the outside of the one current terminal. Alternatively, a four-terminal probe for measuring electrical resistivity, wherein the four terminal probes are arranged so as to intermittently surround, and the other of the two voltage terminals is arranged outside the other current terminal. 8. The electric resistance measuring device according to claim 7, wherein the other voltage terminal is arranged in a circular closed curve so as to annularly surround the outside of the other current terminal. Terminal probe. 9. A four-terminal probe for measuring electrical resistivity, wherein two current terminals and two voltage terminals are spaced apart from each other and in contact with an object to be measured so that they are insulated from each other. One of the two current terminals is disposed so as to continuously or intermittently surround the outside of one of the two voltage terminals, and the other of the two current terminals continuously surrounds the outside of the one current terminal. Alternatively, the four-terminal probe for electric resistivity measurement is arranged so as to intermittently surround, and the other of the two voltage terminals is disposed near the inside of the other current terminal. 10. The one current terminal is arranged in a circular closed curve so as to surround the outside of the one voltage terminal, and the other current terminal is arranged in a circular closed curve so as to surround the outside of the one current terminal. The four-terminal probe for electrical resistivity measurement according to claim 7 or 9, wherein the four-terminal probe is arranged in a shape. 11. A four-terminal probe for measuring electric resistivity, wherein two current terminals and two voltage terminals are spaced apart from each other and in contact with an object to be measured so that they are insulated from each other. One of the two current terminals is disposed so as to continuously or intermittently surround the outside of one of the two voltage terminals, and the other of the two current terminals extends outside the other of the two voltage terminals. A four-terminal probe for measuring electrical resistivity, which is arranged so as to surround continuously or intermittently. 12. The one current terminal is arranged in a circular closed curve so as to surround the outside of the one voltage terminal, and the other current terminal is arranged in a circular closed curve so as to surround the outside of the other voltage terminal. 12. The four-terminal probe for electrical resistivity measurement according to claim 11, wherein the four-terminal probe is arranged in a shape.