JP6161327B2 - Four-terminal resistance measuring device and four-terminal measuring probe - Google Patents

Description

  The present invention relates to a four-terminal resistance measurement device that measures a resistance value of a sample while maintaining a vacuum state of a vacuum chamber, and a four-terminal measurement probe used therefor.

  A current source for supplying a DC measurement current to the measurement sample via the high potential side current supply terminal and the low potential side current supply terminal, and both ends of the measurement sample via the high potential side voltage detection terminal and the low potential side voltage detection terminal A voltage measuring unit that measures the voltage between the two terminals while supplying a high-potential-side AC current for disconnection detection to a high-potential-side current path that includes a high-potential-side current supply terminal and a high-potential-side voltage detection terminal. For detecting disconnection in a low-potential-side current path including a high-potential-side disconnection detector that detects the connection state of both terminals to the measurement sample based on the voltage between one terminal, and a low-potential-side current supply terminal and low-potential-side voltage detection terminal A low-potential-side disconnection detector that detects the connection state of both terminals to the resistor under test based on the voltage between the two terminals generated between the two terminals while supplying the low-potential side alternating current, Two dies connected in parallel at A diode circuit disposed between the current source and the high potential side current supply terminal and between the current source and the low potential side current supply terminal, and the high potential side disconnection detection unit includes: It has a high potential side AC power supply that outputs a high potential side alternating current and the maximum amplitude of the output alternating voltage is less than the turn-on voltage of the diode, and the low potential side disconnection detector outputs a low potential side alternating current. In addition, a low-potential side AC power supply whose maximum output AC voltage amplitude is less than the turn-on voltage of the diode is used. Determine the connection state of the potential-side current supply terminal and high-potential-side voltage detection terminal and the connection state of the low-potential-side current supply terminal and low-potential-side voltage detection terminal to the measurement sample, and measure with the measurement current and measurement section The Based on the voltage across calculates the resistance value of the measurement sample four-terminal resistance measuring device is disclosed (see Patent Document 1). Moreover, the probe for four terminal measurement used for such a four terminal resistance measuring apparatus is disclosed (refer patent document 2).

JP 2011-85462 A JP 2008-45969 A

  When measuring the change in resistance of the sample corresponding to the temperature change of the sample by the four-terminal probe method using a four-terminal probe, or in the state where the physical properties of the sample are stabilized Is measured by a four-terminal needle method using a four-terminal measurement probe, it is necessary to change the temperature of the sample between a high temperature and a low temperature. In order to change the temperature of the measurement sample, the stage on which the sample is mounted is cooled using a refrigerator, and the temperature of the stage is adjusted to a predetermined value using a heater. By adjusting the temperature of the stage to a substantially constant value, the temperature of the measurement sample installed on the stage can be made substantially the same as that of the stage. However, when measuring the resistance value with the measurement sample cooled, the probe temperature of the probe for four-terminal measurement that contacts the sample is normal temperature, so the temperature of the sample rises and is set by the probe probe. The resistance value of the sample cannot be measured while maintaining a constant temperature, and the reliability of the measured resistance value is reduced. In particular, when the temperature of the measurement sample is cooled to an extremely low temperature of 10 to 6 Kelvin, the temperature of the sample increases when a probe at room temperature (for example, 273.15 to 293.15 Kelvin) touches the sample, The temperature of the sample is greatly changed, the sample cannot be kept at a very low temperature, and an accurate resistance value at a very low temperature of the sample cannot be measured.

  An object of the present invention is to provide a four-terminal resistance measuring device capable of preventing a temperature rise of a sample and measuring a highly reliable resistance value even when the probe comes into contact with the measurement sample, and to be used for the same. The object is to provide a four-terminal measurement probe. The object of the present invention is to provide a four-terminal resistance measurement that can maintain the temperature of the sample at a very low temperature even when the probe comes into contact with the measurement sample and can accurately measure the resistance of the sample at a very low temperature. The object is to provide a device and a four-terminal measurement probe used therein.

  The first premise of the present invention for solving the above problems is that a vacuum chamber in which a measurement stage to which a measurement sample can be attached and detached is installed, a vacuum exhaust device and a freezing device connected to the vacuum chamber, and a vacuum chamber. The four-terminal measurement probe, and the refrigeration apparatus is installed at the extended end of the outgoing pipe and flows out the predetermined refrigerant in one direction, and is cooled to a predetermined temperature by the refrigerant. A first cooling stage for transmitting the cold heat to the measurement stage, a return pipe connected to the first cooling stage and allowing the refrigerant to flow into the refrigeration apparatus, and a cooling pipe installed in the return pipe to be cooled to a predetermined temperature by the refrigerant. And a second cooling stage for transmitting to the four-terminal resistance measuring device for measuring the resistance value of the sample while maintaining the vacuum state of the vacuum chamber.

  The four-terminal resistance measurement device of the present invention according to the first premise is characterized in that the four-terminal resistance measurement device is connected to the measurement stage and the second cooling stage to surround the measurement stage, and the cooling heat of the second cooling stage is measured. A heat transfer flexible wire that includes a shield cover that transmits heat to the four-terminal measurement probe is connected to each four-terminal measurement probe under insulation, and the proximal end of the heat transfer flexible wire The portion is connected to the shield cover.

  As an example of the four-terminal resistance measurement device of the present invention, a measurement stage is located inside a vacuum chamber and a sample placement plate for placing a sample; A contact plate and an intermediate plate extending between the sample setting plate and the contact plate, and the shield cover has a front end portion that surrounds the periphery of the sample setting plate, a rear end portion that surrounds the contact plate, and an intermediate plate An intermediate portion surrounding the plate, and a proximal end portion of the heat transfer flexible wire is connected to a front end portion of the shield cover.

  As another example of the four-terminal resistance measurement apparatus of the present invention, a four-terminal measurement probe includes a probe that contacts the sample, a probe guide connected to the rear end of the probe, and a rear end of the probe guide. The heat transfer flexible wire is connected to the probe guide by a crimping terminal attached to the tip end of the second cooling stage. The heat transfer flexible wire is formed from a connected leaf spring and a shaft connected to the rear end of the leaf spring. By transmitting cold heat to the probe guide, the probe is lowered to a predetermined temperature.

  As another example of the four-terminal resistance measuring device of the present invention, the probe guide is a hexahedron made of a conductive metal, and a heat transfer insulating plate abutting on one surface of the probe guide and an insulating layer overlapping one surface of the heat transfer insulating plate In the probe guide, one surface of the crimp terminal attached to the tip of the heat transfer flexible wire is in close contact with one surface of the heat transfer insulation plate, while the inner peripheral surface of the insertion hole formed in the crimp terminal is insulated. The crimp terminal, the heat transfer insulating plate, and the insulating spacer are crimped and fixed to each other with the crimp terminal in contact with the outer peripheral surface of the spacer and insulated from the probe guide.

  As another example of the four-terminal resistance measuring device of the present invention, the heat transfer insulating plate is made of surface-polished sapphire, and the insulating spacer is made of aluminum nitride.

  As another example of the four-terminal resistance measuring device of the present invention, the four-terminal resistance measuring device includes a heating device that heats the sample setting plate, and the temperature of the heat transfer flexible wire is increased by the heat transmitted from the sample setting plate. The probe is raised to a predetermined temperature by transmitting the heated heat at the front end of the shield cover to the probe guide.

  As another example of the four-terminal resistance measuring device of the present invention, the four-terminal resistance measuring device uses a refrigeration device and a heating device, so that the temperature of the sample setting plate and the temperature of the probe are set to 273 on the negative side. The temperature can be changed in the range of .15 to 6 Kelvin, and the temperature of the sample mounting plate can be changed in the range of 273.15 to 473.15 Kelvin on the plus side.

  As another example of the four-terminal resistance measuring device of the present invention, the heat transfer flexible wire is made of an elastically deformable copper stranded wire, and the diameter of the heat transfer flexible wire is in the range of 1 to 1.5 mm. The length of the heat transfer flexible wire is in the range of 5 to 10 cm.

  The second premise of the present invention for solving the above-mentioned problem is that a four-terminal measurement is provided in a vacuum chamber, which has a probe for passing a current through the sample while contacting the measurement sample and measuring the voltage of the sample. Probe.

  The four-terminal measurement probe according to the second premise of the present invention is characterized in that the four-terminal measurement probe is connected to an elastically deformable heat transfer flexible wire that transfers cold or heat to the probe and a rear end of the probe. A probe guide, a leaf spring connected to the rear end of the probe guide, and a shaft connected to the rear end of the plate spring, and the tip of the heat transfer flexible wire is attached to the tip It is attached to the probe guide under insulation by a crimped terminal, and the proximal end of the heat transfer flexible wire is attached to a heat transfer medium cooled or heated by a refrigeration device and a heating device connected to a vacuum chamber, and heat transfer By transmitting the cold energy of the medium to the probe guide, the probe is lowered to a predetermined temperature, and the temperature of the heat transfer medium is transmitted to the probe guide, thereby detecting the probe. Some to raise to a predetermined temperature.

  As an example of the four-terminal measurement probe of the present invention, the probe guide is a hexahedron made of a conductive metal, a heat transfer insulating plate that contacts the one surface, an insulating spacer that overlaps the upper surface of the heat transfer insulating plate, In the probe guide, one surface of the crimp terminal attached to the tip of the heat transfer flexible wire is in close contact with one surface of the heat transfer insulating plate, and the inner peripheral surface of the insertion hole formed in the crimp terminal is an insulating spacer. The crimp terminal, the heat transfer insulating plate, and the insulating spacer are crimped and fixed to each other with the crimp terminal in contact with the outer peripheral surface and insulated from the probe guide.

  As another example of the four-terminal measurement probe of the present invention, in the four-terminal measurement probe, the heat transfer insulating plate is made of surface-polished sapphire, and the insulating spacer is made of aluminum nitride.

  As another example of the four-terminal measurement probe of the present invention, in the four-terminal measurement probe, the heat transfer flexible wire is made of an elastically deformable copper stranded wire, and the diameter of the heat transfer flexible wire is 1 to 1.5 mm. The length of the heat transfer flexible wire is in the range of 5 to 10 cm.

  According to the four-terminal resistance measurement device of the present invention, the heat transfer flexible wires that transmit the cold heat of the second cooling stage to the four-terminal measurement probe are connected to each probe under insulation. Is transmitted from the wire to the probe, the temperature of the probe can be lowered, and even if the probe comes into contact with the sample to pass current through the measurement sample installed on the measurement stage, the temperature of the sample rises due to the heat of the probe The resistance value of the sample can be measured in a state where the temperature of the sample is kept at a predetermined low temperature, and a highly reliable resistance value can be measured. As an example of measuring the resistance of a measurement sample, there is a case where the temperature of the sample is lowered to an extremely low temperature of 10 to 6 Kelvin and the resistance value of the sample is measured in a state where the physical properties of the sample are stabilized. The measuring device can reduce the temperature of the probe for four-terminal measurement to a cryogenic temperature almost the same as that of the sample, so even if the probe contacts the sample, the probe does not increase the temperature of the sample. The resistance value can be measured in a state where the temperature of the sample is kept at a very low temperature, and the accurate resistance value of the sample at a very low temperature can be measured.

  The four-terminal resistance measurement device includes a shield cover that is connected to the measurement stage and the second cooling stage to transmit the cold heat of the second cooling stage to the measurement stage, and the tip of the heat transfer flexible wire is connected to the four-terminal measurement probe. The base end of the heat transfer flexible wire is connected to the shield cover, and the heat of the second cooling stage is transmitted to the measurement stage through the shield cover, and the heat of the second cooling stage is transmitted to the flexible wire through the shield cover. Since the temperature of the measurement stage can be lowered by the shield cover, and the temperature of the probe can be lowered by the wire, even if the probe comes into contact with the measurement sample installed on the measurement stage, the heat of the probe The temperature of the sample does not rise, While maintaining the degree to a predetermined low temperature, it is possible to measure the resistance value of the sample can be measured with high reliability resistance. In the four-terminal resistance measurement device, the temperature of the probe for four-terminal measurement decreases to a cryogenic temperature that is almost the same as that of the sample due to the cold heat transmitted from the flexible wire. The temperature of the sample can be kept at a very low temperature without being raised, and an accurate resistance value at a very low temperature of the sample can be measured.

  After the measurement stage is formed of a sample setting plate for setting the sample, a contact plate connected to the first cooling stage, and an intermediate plate, the shield cover surrounds the front end portion surrounding the peripheral portion of the sample setting plate and the contact plate. A four-terminal resistance measuring device having an end portion and an intermediate portion surrounding the intermediate plate, and the base end portion of the heat transfer flexible wire connected to the front end portion of the shield cover is a shield cover surrounding the peripheral portion of the sample setting plate. Since the base end of the wire is connected to the front end of the wire, the distance from the base end to the tip of the wire (the length of the wire) is short, and heat loss in the wire can be minimized. 2 Cooling heat from the cooling stage is reliably transmitted from the wire to the probe, and the temperature of the probe is lowered to substantially the same temperature as that of the shield cover. Door can be. The four-terminal resistance measurement device maintains the sample temperature at a predetermined or extremely low temperature without causing the sample temperature to rise due to the probe heat even if the probe contacts the measurement sample installed on the measurement stage. In this state, the resistance value of the sample can be measured, and a highly reliable resistance value at a low temperature or an extremely low temperature can be measured.

  A four-terminal measuring probe is formed of a probe that contacts the sample, a probe guide, a leaf spring, and a shaft, and a heat transfer flexible wire is connected to the probe guide by a crimp terminal attached to the tip of the probe. The four-terminal resistance measurement device that lowers the probe to a predetermined temperature by transmitting the cold heat of the probe to the probe guide transmits the cold heat of the second cooling stage to the flexible wire through the shield cover, and by the cold heat of the wire transmitted to the probe guide Since the temperature of the probe can be lowered together with the probe guide, the temperature of the probe can be lowered to substantially the same temperature as that of the shield cover. Even if the probe tip contacts the measurement sample installed on the measurement stage, the four-terminal resistance measurement device does not increase the temperature of the sample due to the heat of the probe. The resistance value of the sample can be measured in a state kept at a very low temperature, and a highly reliable resistance value at a low temperature or a very low temperature can be measured.

  The probe guide includes a heat transfer insulating plate and an insulating spacer, and one surface of the crimp terminal attached to the tip of the heat transfer flexible wire is in close contact with one surface of the heat transfer insulating plate, and the insertion hole formed in the crimp terminal is A four-terminal resistance measurement device with a crimp terminal, heat transfer insulation plate, and insulation spacer fixed by crimping with the inner peripheral surface in contact with the outer peripheral surface of the insulation spacer and the crimp terminal insulated from the probe guide. Since the crimp terminal attached to the tip of the wire is interposed between the heat transfer insulating plate and the insulating spacer and fixed to the probe guide, the four-terminal measuring probe and the wire can be reliably insulated. The four-terminal resistance measurement device does not cause the wire to be electrically connected to the probe and the current does not fall to the ground through the wire. An accurate resistance value at a predetermined temperature can be measured.

  The four-terminal resistance measuring device, where the heat transfer insulation plate is made of surface-polished sapphire and the insulation spacer is made of aluminum nitride, the sapphire's excellent thermal conductivity and excellent insulation and insulation spacer excellent insulation By utilizing this property, the four-terminal measurement probe and the wire can be reliably insulated, and the cold and hot heat of the wire can be reliably transmitted to the probe probe through the sapphire. Even if the probe contacts the sample, the four-terminal resistance measurement device does not change the temperature of the measurement sample, and can maintain the sample in a low temperature state (very low temperature state) or a high temperature state. An accurate resistance value at low temperature (very low temperature) or high temperature can be measured.

  It includes a heating device that heats the sample setting plate, and the heat transfer flexible wire transmits the temperature of the front end of the shield cover whose temperature has been increased by the heat transferred from the sample setting plate to the probe guide, so that the probe is brought to a predetermined temperature. The four-terminal resistance measuring device to be raised can change the temperature of the measurement stage and the probe tip between the high temperature and the low temperature (very low temperature) by using a refrigeration device and a heating device. The temperature of the measurement sample can be set to the optimum value of the sample at the time of resistance measurement, and the resistance value of the sample can be measured in a state where the temperature of the sample is maintained at the optimum value. The four-terminal resistance measurement device can measure the resistance value of the sample at each temperature by changing the temperature of the measurement stage and the probe tip. Therefore, it measures the change in the resistance value of the sample due to the temperature change. be able to. Even if the temperature of the measurement stage changes between high temperature and low temperature (very low temperature), the probe temperature also changes between the high temperature and low temperature (very low temperature) according to that of the measurement stage. Therefore, the temperature change of the sample when the probe comes into contact with the sample can be prevented, and an accurate resistance value at a predetermined temperature of the sample can be measured.

  By using the freezing device and the heating device, the temperature of the sample setting plate and the temperature of the probe can be changed to the minus side in the range of 273.15 to 6 Kelvin. The four-terminal resistance measurement device, which can change the temperature in the range of 273.15 to 473.15 Kelvin (0 to 200 ° C.) on the plus side, changes the temperature of the sample installation plate and the probe to high and low temperatures (very low temperature). Therefore, it is possible to change the temperature of the measurement sample to the optimum value of the sample at the time of resistance measurement, and measure the resistance value of the sample while keeping the temperature of the sample at the optimum value. be able to. For example, when the sample is cooled to a cryogenic temperature of 10 to 6 Kelvin, the four-terminal resistance measuring device assumes that the probe is in contact with the sample because the probe is also cooled to a cryogenic temperature substantially the same as the sample. However, the temperature of the measurement sample does not increase, the sample can be kept at a very low temperature, and the accurate resistance value at the very low temperature of the sample can be measured. For example, when the sample is heated to a high temperature of 423.15 to 473.15 Kelvin (150 to 200 ° C.), the temperature of the probe can be increased. The temperature of the measurement sample does not decrease, the sample can be maintained at a high temperature, and an accurate resistance value at a high temperature of the sample can be measured.

  A four-terminal resistance measuring device in which the heat transfer flexible wire is made of elastically deformable copper stranded wire, the wire diameter is in the range of 1 to 1.5 mm, and the wire length is in the range of 5 to 10 cm. Since it is made of a high-conductivity copper stranded wire, it is possible to reliably transmit cold and hot heat to the probe tip via the wire. Since the diameter and length of the heat transfer flexible wire are in the above range, the four-terminal resistance measuring device can secure the degree of freedom of the wire while maintaining the efficiency of heat conduction of the wire. Not only can cold and hot heat be transmitted to the probe tip, the wire can move freely according to the movement of the probe.

  According to the probe for measuring four terminals according to the present invention, it has a heat transfer flexible wire that is elastically deformable to transmit cold or heat to the probe, and the base end of the wire is cooled or heated by a refrigeration apparatus and a heating apparatus. Since it is attached to the heat transfer medium, it is possible to transmit cold or hot heat to the probe through the wire, and the temperature of the probe can be adjusted to a desired value. For example, when a four-terminal measurement probe is used in a four-terminal resistance measurement device that measures the resistance value of a sample while adjusting the measurement sample to a predetermined temperature, the temperature of the probe is controlled by the cold or heat transmitted from the wire. Because it can be made almost the same, it can prevent the temperature change of the sample when the probe contacts the sample, and measure the resistance value of the sample while keeping the sample temperature constant Can do.

The four-terminal measuring probe is formed of a probe guide connected to the rear end of the probe, a plate spring connected to the rear end of the probe guide, and a shaft connected to the rear end of the plate spring, and transfers heat. A flexible wire is attached to the probe guide by a crimping terminal attached to the tip of the flexible wire, and transmits the cold heat of the heat transfer medium to the probe guide, so that the probe is lowered to a predetermined temperature, and the heat of the heat transfer medium is transferred to the probe guide. by transmitting, from raising the probe to a predetermined temperature, with the proximal end portion of the wire is attached to the heat transfer medium cooled or heated by the refrigeration system and the heating device, the tip of the wire is attached to the probe guide in the cold or heat it can tell probe via a wire, the temperature of the probe can be adjusted desired it .

  The probe guide includes a heat transfer insulating plate and an insulating spacer, and one surface of the crimp terminal attached to the tip of the heat transfer flexible wire is in close contact with one surface of the heat transfer insulating plate, and the insertion hole formed in the crimp terminal is A four-terminal measurement probe with a crimping terminal, heat transfer insulation plate, and insulation spacer fixed by crimping with the inner circumferential surface in contact with the outer circumferential surface of the insulating spacer and the crimping terminal insulated from the probe guide. Since the crimp terminal attached to the tip of the wire is interposed between the heat transfer insulating plate and the insulating spacer and fixed to the probe guide, the four-terminal measuring probe and the wire can be reliably insulated. In the four-terminal measurement probe, the wire is not electrically connected to the probe, and the current does not fall to the ground through the wire, so that the current can be reliably supplied to the measurement sample by the probe.

  The probe for four-terminal measurement, where the heat transfer insulation plate is made of surface-polished sapphire and the insulation spacer is made of aluminum nitride, the sapphire's excellent thermal conductivity and excellent insulation and insulation spacer's excellent insulation By utilizing this property, the four-terminal measurement probe and the wire can be reliably insulated, and the cold and hot heat of the wire can be reliably transmitted to the probe probe through the sapphire. Even if the probe contacts the sample, the four-terminal measurement probe does not change the temperature of the measurement sample, and measures the resistance value of the sample while keeping the sample temperature constant. Can do.

  The four-terminal measuring probe, in which the heat transfer flexible wire is made of elastically deformable copper stranded wire and the wire diameter is in the range of 1 to 1.5 mm and the wire length is in the range of 5 to 10 cm, is the heat transfer flexible Since the diameter and length of the wire are within the above ranges, the degree of freedom of the wire can be ensured while maintaining the efficiency of heat conduction of the wire, and cold and hot heat are transmitted to the probe probe via the wire. The wire can move freely according to the movement of the probe.

The side view of the four-terminal resistance measuring apparatus shown as an example. The perspective view of the four-terminal resistance measuring apparatus which abbreviate | omits and shows an evacuation mechanism. The top view of a four-terminal resistance measuring apparatus. The side view of the four-terminal resistance measuring apparatus which shows a vacuum chamber and a vacuum vessel partially broken. The top view of a measurement stage. The top view of the vacuum chamber which abbreviate | omitted the XYZ stage. The enlarged top view of a measurement stage. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. The perspective view of a measurement stage. The perspective view of the probe for four terminal measurement. The top view of the probe for four terminal measurement. The side view of the probe for four terminal measurement. The enlarged side view of a probe guide and a heat transfer flexible wire. The figure which shows the attachment procedure of the heat transfer flexible wire with respect to a probe guide. The figure which shows the procedure which installs a measurement sample in the sample installation location of a sample installation plate.

  The details of the four-terminal resistance measuring device according to the present invention and the four-terminal measuring probe used therein will be described with reference to the accompanying drawings such as FIG. 1 which is a side view of the four-terminal resistance measuring device 10 shown as an example. It is as follows. 2 is a perspective view of the four-terminal resistance measurement device 10 with the vacuum evacuation mechanism 15 omitted, and FIG. 3 is a top view of the four-terminal resistance measurement device 10. FIG. 4 is a side view of the four-terminal resistance measuring device 10 showing the vacuum chamber 11 and the vacuum vessel 12 partially broken, and FIG. 5 is a top view of the measurement stage 13. FIG. 6 is a top view of the vacuum chamber 11 in which the XYZ stage 31 is omitted, and FIG. 7 is an enlarged top view of the measurement stage 13. 8 is a cross-sectional view taken along line 8-8 in FIG. In FIG. 1, the vertical direction is indicated by A, and the front-back direction is indicated by arrow B.

  The four-terminal resistance measuring device 10 includes a vacuum chamber 11, a vacuum vessel 12 (refrigerator chamber), a measurement stage 13, a shield cover 14, a vacuum exhaust mechanism 15 (vacuum exhaust device), a helium refrigerating mechanism 16 (refrigeration device), and a heater 17. (Heating device) and four-terminal measuring probes 18a to 18d. The four-terminal resistance measuring device 10 is installed on a gantry 19 to which a caster is attached and can be freely moved by the caster.

  Although not shown in the figure, a controller (control device) that controls the device 10 is connected to the four-terminal resistance measurement device 10 (including a case where the device 10 includes a controller). The four-terminal resistance measurement apparatus 10 cools or heats the measurement sample 20 to maintain the temperature of the sample 20 at the set temperature, while maintaining the vacuum state of the vacuum chamber 11 at the set vacuum degree. The resistance value (volume resistivity [Ω · cm]) per unit volume of the sample 20 is measured by (four terminal method). The sample 20 is not particularly limited as long as it is a conductor or semiconductor having electrical conductivity (electrical resistivity), and the thickness dimension is not particularly limited.

  The vacuum chamber 11 is formed in a cylindrical shape extending in the vertical direction, and includes circular top and bottom walls 21 and 22 and a peripheral wall 23 extending between the walls 21 and 22. In the vacuum chamber 11, an internal space 24 having a predetermined volume is defined. When measuring the resistance value of the measurement sample 20, the internal space 24 of the chamber 11 is held in a vacuum by the vacuum exhaust mechanism 15. The top wall 21 of the chamber 11 has a peripheral edge portion 25 and a central portion 26. The peripheral portion 25 is made of stainless steel (may be made of aluminum or duralumin), and the central portion 26 is made of transparent shielding glass.

  The peripheral edge 25 of the top wall 21 is airtightly fixed to the top of the peripheral wall 23 by a plurality of bolts arranged in the circumferential direction. The top wall 21 can be separated from the peripheral wall 23 by removing the bolt. The bottom wall 22 is made of stainless steel (may be made of aluminum or duralumin). The bottom wall 22 is airtightly fixed to the top of the peripheral wall 23 by a plurality of bolts whose peripheral edge is arranged in the circumferential direction. The bottom wall 22 can be separated from the peripheral wall 23 by removing the bolt. The peripheral wall 23 is made of stainless steel (may be made of aluminum or duralumin).

  A joint pipe 27 extending in the front-rear direction is formed on the peripheral wall 23 of the vacuum chamber 11, and a preliminary connection port 30 that is hermetically closed by an XYZ stage connection port 28 and a sealing lid 29 arranged in the peripheral direction is formed. ing. Four XYZ stages 31 arranged in the direction around the peripheral wall 23 of the chamber 11 are airtightly attached to the XYZ stage connection port 28. Four-terminal measurement probes 18a to 18d (a shaft 56 described later of the probes 18a to 18d) are detachably attached to the XYZ stage 31. The XYZ stage 31 moves the four-terminal measurement probes 18a to 18d (probe 53 to be described later of the probes 18a to 18d) in the X axis direction, the Y axis direction, and the Z axis direction. By using the XYZ stage 31, the contact position of the probe 53 with respect to the measurement sample 20 can be adjusted by moving the probe 53 three-dimensionally.

  Although not shown, the vacuum chamber 11 is provided with a vacuum gauge (pressure sensor). The vacuum gauge is connected to the controller via an interface. The vacuum gauge measures the vacuum pressure in the internal space 24 of the vacuum chamber 11 and outputs the measured vacuum pressure to the controller. The controller measures the degree of vacuum in the internal space 24 based on the vacuum pressure output from the vacuum gauge.

  The controller is a computer having a central processing unit (CPU or MPU) and memory (main memory and cache memory), and has a built-in large-capacity hard disk. Input / output devices such as a numeric keypad unit, keyboard, multi-touch panel, display, and printer are connected to the controller via an interface. The central processing unit of the controller activates an application from the memory based on the control by the operating system, and performs various controls of the four-terminal resistance measuring device 10 according to the activated application.

  The vacuum vessel 12 is made of stainless steel (may be made of aluminum or duralumin). The vacuum vessel 12 is formed in a cylindrical shape that is long in the vertical direction. A predetermined volume of the internal space 32 is defined in the vacuum container 12. A helium refrigeration mechanism 16 is detachably installed on the upper portion of the vacuum vessel 12. A joint pipe 33 extending in the front-rear direction is formed at the center of the vacuum vessel 12. A first exhaust pipe 34 extending in the vertical direction is formed at the lower portion of the vacuum vessel 12.

  The vacuum vessel 12 (helium refrigerating mechanism 16) is connected to the vacuum chamber 11 via a joint pipe 33. The joint pipe 27 made in the vacuum chamber 11 and the joint pipe 33 made in the vacuum vessel 12 are in contact with each other and the flanges extending in the radial direction of the joint pipes 27 and 33 are fixed by bolts. And are connected to each other in an airtight manner.

  The measurement stage 13 is a plate-like member extending straight in the front-rear direction, and reaches the internal space 32 of the vacuum vessel 12 from the internal space 27 of the vacuum chamber 11 through the joint pipes 27 and 33. The measurement stage 13 is made of copper having high thermal conductivity (thermal conductivity). The measurement stage 13 includes a sample installation plate 35 having a predetermined thickness on which the measurement sample 20 is detachably installed, a contact plate 37 having a predetermined thickness located in the internal space 32 of the vacuum vessel 12 (on the helium refrigeration mechanism 16 side), An intermediate plate 36 having a predetermined thickness extending between the sample setting plate 35 and the contact plate 37 is formed.

  As shown in FIG. 5, the sample placement plate 35 is formed into a circular planar shape and is located in the internal space 24 of the vacuum chamber 11. The sample placement plate 35 is provided with a temperature sensor (not shown) for measuring the temperature. The temperature sensor is connected to the controller via the interface, and outputs the measured temperature of the plate 35 to the controller. The intermediate plate 36 is located in the joint pipes 27 and 33.

  The shield cover 14 is a plate-like member extending straight in the front-rear direction, and reaches the internal space 32 of the vacuum vessel 12 from the internal space 24 of the vacuum chamber 11 through the joint pipes 27 and 33. The shield cover 14 (including the fixing seat 42 described later) is made of copper having high thermal conductivity (thermal conductivity). The shield cover 14 is located outside the sample setting plate 35 of the measurement stage 13 and surrounds the front end 38 surrounding the plate 35 and the outside of the contact plate 37 and surrounds the entire plate 37 (covers the whole). It has a rear end portion 40 and an intermediate portion 39 which is located outside the intermediate plate 36 and surrounds (encloses) the entire plate 36.

  The front end portion 38 of the shield cover 14 is located in the internal space 24 of the vacuum chamber 11. The front end portion 38 is formed of a ring-shaped portion and a disk-shaped fixed seat 42, and the portion formed in a ring shape is positioned in the vicinity of the peripheral edge portion 41 of the sample setting plate 35. The entire periphery of the peripheral edge portion 41 is surrounded. Note that the annularly shaped portion of the front end portion 38 does not contact the peripheral edge portion 41 of the sample setting plate 35 and is not in contact. The ring-shaped part and the fixing seat 42 are closely fixed by a plurality of screws arranged in the peripheral direction. The intermediate portion 39 is located inside the joint pipes 27 and 33, and the rear end portion 40 is located in the internal space 32 (the refrigeration mechanism 16 side) of the vacuum vessel 12. The rear end portion 40 extends from the intermediate portion 39 in the front-rear direction, and then extends upward toward the refrigeration mechanism 16. A portion of the rear end portion 40 extending upward toward the refrigeration mechanism 16 is formed in a cylindrical shape.

  The vacuum evacuation mechanism 15 (vacuum evacuation device) is positioned below the vacuum vessel 12 and is airtightly connected (communication) to the vacuum chamber 11 by being airtightly connected to the first exhaust pipe 34 of the vacuum vessel. . The vacuum exhaust mechanism 15 exhausts the air in the internal spaces 24 and 32 of the vacuum chamber 11 and the vacuum vessel 12 and depressurizes the spaces 24 and 32 to a vacuum. The vacuum exhaust mechanism 15 is formed by a turbo molecular pump 43 (main vacuum pump) installed immediately below the exhaust pipe 34 and a roughing pump 44 (auxiliary vacuum pump) disposed downstream of the turbo molecular pump 43. ing. The turbo molecular pump 43 is connected (communication) to the vacuum vessel 12 through the first exhaust pipe 34. The turbo molecular pump 43 compresses and exhausts gas molecules by rotating a rotor having turbine blades at a high speed. The turbo molecular pump 43 is used to evacuate the internal spaces 24 and 32 of the vacuum chamber 11 and the vacuum vessel 12.

  The roughing pump 44 is connected (communication) to the turbo molecular pump 43 via the second exhaust pipe 45. The roughing pump 44 covers the point where the turbo molecular pump 43 cannot compress to atmospheric pressure, and maintains the exhaust pressure of the second exhaust pipe 45 at a predetermined pressure. As the roughing pump 44, a rotary pump, a high vacuum diaphragm pump, a dry vacuum pump, or the like can be used. When the outputs of the turbo molecular pump 43 and the roughing pump 44 are adjusted by the controller, the controllers of the pumps 43 and 44 are connected to the controller via the interface. When the pumps 43 and 44 are not adjusted by the controller, the controllers of the pumps 43 and 44 are connected to the pump controller.

  The helium refrigeration mechanism 16 (refrigeration apparatus) employs a helium refrigeration system to freeze the sample 20 (subject to be frozen) at a very low temperature. The helium refrigeration mechanism 16 includes a helium refrigerator 46, a forward pipe 49 extending downward from the refrigerator 46, a first cooling stage 48 installed at a downwardly extending end of the forward pipe 49, and a first cooling stage 48. The return pipe 49 is connected to the return pipe 49 and makes a U-turn and extends upward, and the second cooling stage 50 is installed at a substantially central portion of the return pipe 49.

  Although not shown, the helium refrigerator 46 is formed of a helium compressor, an expansion turbine, a heat exchanger, and a Joule Thomson valve. The helium refrigerator 46 is detachably attached to the top of the vacuum vessel 12. The helium refrigerator 46 is connected to a helium gas relay box 51 in which helium gas (refrigerant) is introduced from the outside and the helium gas is stored under compression. The helium refrigerator 46 has a controller connected to the controller via an interface.

  The outgoing pipe 47 and the return pipe 49 are made of stainless steel (may be made of aluminum or duralumin). The first cooling stage 48 and the second cooling stage 50 are made of copper having high thermal conductivity (thermal conductivity). The outgoing pipe 47, the return pipe 49, the first cooling stage 48, and the second cooling stage 50 are accommodated in the internal space 32 of the vacuum vessel 12.

  The outgoing pipe 47 causes the helium gas sent from the helium refrigerator 46 to flow (outflow) downward (in one direction). The return pipe 49 causes the helium gas that has flowed through the outgoing pipe 47 to flow (inflow) toward the helium refrigerator 46 and return the helium gas to the refrigerator 46. After the helium gas is supplied from the helium gas relay box 51 to the helium refrigerator 46, the helium refrigerator 46 → the outgoing pipe 47 → the first cooling stage 48 → the return pipe 49 (second cooling stage 50) → the refrigerator 46 Cycle in order.

  The outgoing pipe 47 is provided with a flow meter. The flow meter is connected to the controller via an interface. The flow meter measures the flow rate of helium gas flowing through the outgoing pipe 47 and outputs the measured flow rate to the controller. The controller measures the flow rate of helium gas flowing through the outgoing pipe 47 based on the flow rate output from the flow meter. The first cooling stage 48 is formed in a cylindrical shape and has a lower surface with a predetermined area. The entire upper surface of the contact plate 37 of the measurement stage 13 is in contact with (adhered to) the entire lower surface of the first cooling stage 48. The first cooling stage 48 is cooled to an extremely low temperature by flowing helium gas therein.

  The first cooling stage 48 cooled by the helium gas transmits the cold heat to the contact plate 37 (measurement stage 13). The cold heat transmitted from the first cooling stage 48 to the contact plate 37 is transmitted from the contact plate 37 to the intermediate plate 36 and from the intermediate plate 36 to the sample setting plate 35. The entire measurement stage 13 is cooled to a very low temperature by the cold heat transmitted from the first cooling stage 48.

  The 2nd cooling stage 50 is shape | molded by the column shape, and the rear-end part 40 of the shield cover 14 is connected to the lower surface. The second cooling stage 50 surrounds the substantially central portion of the forward pipe 47, but does not contact the outer peripheral surface of the forward pipe 47 and is not in contact. The second cooling stage 50 is cooled to an extremely low temperature by flowing helium gas therein. The second cooling stage 50 cooled by the helium gas transmits the cold heat to the rear end portion 40 of the shield cover 14. Cold heat transmitted from the second cooling stage 50 to the rear end portion 40 of the shield cover 14 is transmitted from the rear end portion 40 to the intermediate portion 39 and from the intermediate portion 39 to the front end portion 38. The entire shield cover 13 is cooled to a very low temperature by the cold heat transmitted from the second cooling stage 50. Since the front end portion 38 of the shield cover 13 surrounds the vicinity of the peripheral portion 41 of the sample setting plate 35, the cold heat of the front end portion 38 is transmitted to the vicinity of the peripheral portion 41 of the plate 35.

  The sample setting plate 35 (measurement stage 13) is cooled by the cold heat transmitted from the first cooling stage 48, but the heat of the plate 35 (the temperature of the internal space 24 of the vacuum chamber 11) transmitted from the peripheral edge portion 41 of the plate 35. When the temperature rises, the temperature of the plate 35 may not be maintained at a substantially constant low temperature or extremely low temperature. However, since the front end portion 38 of the shield cover 14 surrounds the vicinity of the peripheral edge portion 41 of the sample setting plate 35 and the cold heat of the front end portion 38 is transmitted to the vicinity of the peripheral edge portion 41 of the plate 35, the vicinity of the peripheral edge portion 41 is cooled by the front end portion 38. Thus, the temperature rise of the peripheral edge portion 41 of the plate 35 is prevented, and the temperature of the plate 35 is maintained at a substantially constant low temperature or extremely low temperature.

  The heater 17 (heating device) is installed on the lower surface of the central portion of the sample installation plate 35 and heats the plate 35. The heater 17 is connected to the controller via an interface. The heater 17 is used not only to raise the temperature of the sample setting plate 35 to a predetermined high temperature but also to adjust the temperature of the plate 35. For example, when the helium refrigeration mechanism 16 is activated and the cold heat from the refrigerator 46 is transmitted to the sample installation plate 35, the controller moves the plate 35 while the heater 17 is stopped or the heater 17 is operated. Heat and adjust the temperature of the plate 35 to the minus side (0 ° C. or lower).

  In addition, when the helium refrigeration mechanism 16 is stopped and the cold heat from the refrigerator 46 is not transmitted to the sample installation plate 35, the controller heats the sample installation plate by operating the heater 17 and increases the plate temperature. Adjust to the side (above 0 ° C). The four-terminal resistance measuring device 10 can be changed to the minus side in the range of 273.15 to 6 Kelvin, and can be held at the set temperature on the minus side. Moreover, it can change in the range of 273.15-473.15 Kelvin (0-200 degreeC) to the plus side, and can be hold | maintained to the setting temperature of the plus side.

  FIG. 9 is a perspective view of the measurement stage 13 and shows a state in which the probes of the four-terminal measurement probes 18 a to 18 d are in contact with the upper surface of the measurement sample 20. 10 is a perspective view of the four-terminal measurement probes 18a to 18d, and FIG. 11 is a top view of the four-terminal measurement probes 18a to 18d. FIG. 12 is a side view of the four-terminal measurement probes 18 a to 18 d, and FIG. 13 is an enlarged side view of the probe guide 54 and the heat transfer flexible wire 57. 14 is a diagram showing a procedure for attaching the heat transfer flexible wire 57 to the probe guide 54, and FIG. 15 is a diagram showing a procedure for installing the measurement sample 20 at the sample installation location of the sample installation plate 35. Illustration of the measurement probes 18a to 18d is omitted.

  In the four-terminal resistance measuring device 10, four four-terminal measuring probes 18a to 18d are installed. Two of the four-terminal measurement probes 18a to 18d are current-carrying probes 18a and 18d for applying a predetermined current to the measurement sample 20 (for applying a voltage to apply a predetermined voltage). One is voltage measuring probes 18b and 18c for measuring the voltage of the sample 20. These four-terminal measurement probes 18a to 18d are connected to the controller via an interface. These four-terminal measuring probes 18 a to 18 d are formed of a probe 53 and a probe guide 54, a leaf spring 55 and a shaft 56, and a heat transfer flexible wire 57.

  The probe 53 is a conductive metal needle that extends from the probe guide 54 and bends downward toward the measurement sample 20 (from the rear end to the front end), and has high thermal conductivity (thermal conductivity) and high electrical conductivity. Made of copper with conductivity (electrical conductivity) (may be made of silver or aluminum). The probe 53 has a front end 58 that contacts the upper surface of the measurement sample 20 and a rear end 59 supported by the probe guide 54.

  The probe guide 54 is a quadrangular prism-shaped hexahedron, and is made of copper having high thermal conductivity (thermal conductivity) and high electrical conductivity (electrical conductivity) (may be made of silver or aluminum). ). The probe guide 54 is electrically connected to the rear end 59 of the probe 53. The probe guide 54 includes a heat transfer insulating plate 61 that abuts one surface 60 (side surface) thereof, an insulating spacer 63 that overlaps the upper surface 62 of the heat transfer insulating plate 61, and a guide block 65 that extends from the rear end portion 64. . A screw screw hole 67 into which a screw 66 is screwed is formed at the center of one surface 60 of the probe guide 54.

  The heat transfer insulating plate 61 is made of sapphire having excellent thermal conductivity (thermal conductivity) and excellent insulating properties. As shown in FIG. 14, the heat transfer insulating plate 61 is molded into a rectangular plate shape having a predetermined thickness, and each surface thereof is polished. A screw insertion hole 68 through which the screw 66 is inserted or screwed is formed in the central portion of the heat transfer insulating plate 61. The guide block 65 is made of synthetic resin, and a semicircular receiving seat 70 that supports the electric wire 69 is formed.

  The insulating spacer 63 is made of aluminum nitride having excellent thermal conductivity (thermal conductivity) and excellent insulating properties. The insulating spacer 63 is formed of a square stop seat 71 and a cylinder 72 extending downward from the stop seat 71. A screw insertion hole 72 through which a screw 66 is inserted or screwed is formed in the central portion of the stopper seat 71 and the cylinder 72 of the insulating spacer 63. The leaf spring 55 is made of synthetic resin and molded into a plate shape. The front end of the leaf spring 55 is fixed to the guide block 65 (rear end 64 of the probe guide 54) with screws. The shaft 56 is made of a synthetic resin and is formed into a cylindrical shape having a through hole 73. An electric wire 69 is inserted through the through hole 73 of the shaft 56. The bare wire of the electric wire 69 is electrically connected to the probe guide 54. The front end portion of the shaft 56 is fixed to the rear end portion of the leaf spring 55 with a screw, and the rear end portion thereof is connected to the XYZ stage 31.

  The heat transfer flexible wire 57 is made of an elastically deformable copper stranded wire having high thermal conductivity (thermal conductivity) (may be made of a silver stranded wire or an aluminum stranded wire). Crimp terminals 76 and 77 are attached to the distal end portion 74 and the proximal end portion 75 of the wire 57. The crimp terminals 76 and 77 are made of copper having high thermal conductivity (thermal conductivity) (may be made of silver or aluminum).

  A spacer insertion hole 78 through which the cylinder 72 of the insulating spacer 63 is inserted is formed in the central portion of the crimp terminal 76 attached to the distal end portion 74 of the heat transfer flexible wire 57. A screw insertion hole through which a screw 79 is inserted or screwed is formed in the central portion of the crimp terminal 77 attached to the base end portion 75 of the wire 57. The base end portion 75 of the wire 57 is fixed by inserting or screwing a screw 79 into a screw insertion hole of the crimp terminal 77 and screwing the screw 79 into a screw screw hole formed in the fixed seat 42. The seat 42 (the front end 38 of the shield cover 14) is fixed by crimping. The front end portion 38 of the shield cover 14 and the crimp terminal 77 (heat transfer flexible wire 57) are connected so as to be capable of heat conduction.

  The distal end portion 74 of the heat transfer flexible wire 57 is attached to the probe guides 54 of the four-terminal measuring probes 18a to 18d through the crimping terminal 76 so as to be thermally conductive and insulated. The mounting procedure is such that one surface 80 (lower surface) of the heat transfer insulating plate 61 (sapphire) is superposed on one surface 60 (side surface) of the probe guide 54 and the crimp terminal 76 is disposed on the other surface 62 (upper surface) of the plate 61. One surface 81 (lower surface) is overlapped. Next, the cylinder 72 of the insulating spacer 63 is inserted into the spacer insertion hole 78 of the crimp terminal 76, the shaft of the screw 66 is inserted or screwed into the spacer 63 and the screw insertion holes 68, 72 of the heat transfer insulating plate 61, and The screw 66 is screwed into the screw screw hole 67 of the probe guide 54.

  When the screw 66 is screwed to the probe guide 54, one surface 81 (lower surface) of the crimp terminal 76 is in close contact with one surface 62 (upper surface) of the heat transfer insulating plate 61, and the inner peripheral surface 82 of the spacer insertion hole 78 of the crimp terminal 76. Is in contact with the outer peripheral surface 83 of the cylinder 72 of the insulating spacer 63 and the crimp terminal 76 is insulated from the probe guide 54, and the crimp terminal 76, the heat transfer insulating plate 61, and the insulating spacer 63 are interposed via the screws 66. Are fixed to each other by crimping. The crimp terminal 76 is not in contact with the probe guide 54 and the screw 66, and the crimp terminal 76 (heat transfer flexible wire 57) and the probe guide 54 (probe 53) are connected in a non-conducting state (insulated state). The crimp terminal 76 (heat transfer flexible wire 57) and the probe guide 54 (probe 53) are connected so as to be able to conduct heat.

  The cold heat of the front end portion 38 (fixed seat 42) of the shield cover 14 cooled to an extremely low temperature by the cold heat transmitted from the second cooling stage 50 is transmitted from the crimp terminal 77 to the heat transfer flexible wire 57 and from the wire 57 to the crimp terminal 76. After being transmitted, it is transmitted from the crimp terminal 76 to the probe guide 54 and from the guide 54 to the probe 53. The entire probe 53 is cooled to a very low temperature by the cold heat transmitted from the probe guide 54.

  The heat transfer flexible wire 57 has a diameter of 1 to 1.5 mm and a length of 5 to 10 cm. If the diameter of the wire 57 is less than 1 mm, the heat conduction efficiency of the wire 57 is lowered, and cold or warm heat cannot be sufficiently and smoothly transmitted from the proximal end portion 75 of the wire 57 to the distal end portion 74. When the diameter of the wire 57 exceeds 1.5 mm, the rigidity of the wire 57 is increased more than necessary, and the degree of freedom of the wire 57 is lost, and the wire 57 can freely move according to the movement of the four-terminal measurement probes 18a to 18d. It cannot move, and it becomes difficult to position the contact position of the probe 53 with respect to the measurement sample 20. When the length of the wire 57 exceeds 10 cm, the heat conduction time of the wire 57 increases, and cold heat or heat cannot be quickly transmitted from the proximal end portion 75 of the wire 57 to the distal end portion 74.

  An example of the measurement procedure of the electrical resistance (resistance value) of the measurement sample 10 in the four-terminal resistance measurement device 10 using the four-terminal measurement probes 18a to 18d is as follows. The hard disk of the controller has a set vacuum degree of the vacuum chamber 11 (including the vacuum vessel 12), a set temperature of the sample setting plate 35 (measurement stage 13), and a current flowing from the four-terminal measuring probes 18a and 18d to the sample 20. , The set voltage value of the voltage applied to the sample 20 from the probes 18a and 18d, and the set energization time of the current flowing from the probes 18a and 18d to the sample 20 are stored. The set vacuum degree, set temperature, set current value, set voltage value, and set energization time can be freely changed by an input device connected to the controller.

  The central processing unit of the controller stops (OFF) or starts (ON) the four-terminal resistance measuring device 10 (including each sensor), starts and stops the vacuum exhaust mechanism 15, starts and stops the helium refrigeration mechanism 16, and starts the heater 17. Stopping is performed to keep the vacuum degree of the vacuum chamber 12 at the set vacuum degree, and keep the temperature of the sample setting plate 35 (measurement stage 13) at the set temperature.

  The central processing unit of the controller holds the current value flowing from the probe 53 of the four-terminal measurement probes 18a and 18d to the measurement sample 20 at the set current value, and applies it to the sample 20 from the probe 53 of the probes 18a and 18d. The voltage value is held at the set voltage value, and a current is passed from the probe 53 of the probes 18a and 18d to the sample 20 during the set energization time (voltage is applied). Further, the resistance value (volume resistivity [Ω · cm]) per unit volume of the sample 29 is calculated by the four-end needle method (four-terminal method) from the current passed through the sample 20 and the measured voltage.

  First, the measurement sample 20 is installed at the sample installation location of the sample installation plate 35 (measurement stage 13). After screw screwing is released and the top wall 21 of the vacuum chamber 12 is removed from the peripheral wall 23 and the sample setting plate 35 is exposed, screw screwing is released and the sample presser fitting 52 is removed from the plate 35, The measurement sample 20 is installed at a sample installation location at approximately the center of 35 (see FIG. 15). At this time, the probe 53 of the four-terminal measurement probes 18 a to 18 d is moved outward in the radial direction of the installation location of the sample installation plate 35 by the XYZ stage 31. Further, the evacuation mechanism 15 is stopped, and the refrigeration mechanism 16 and the heater 17 are stopped.

  After the sample 20 is installed at the sample installation location of the plate 35, screws are screwed to fix the sample presser fitting 52 to the sample installation location, and the periphery of the sample 20 is fixed by the presser fixture 52. Since the presser fitting 52 fixes the peripheral edge of the sample 20, the sample 20 is firmly fixed to the sample installation location of the plate 35. After fixing the presser fitting 52 to the installation location, screws are screwed to fix the top wall 21 to the peripheral wall 23 in an airtight manner. After the top wall 21 is fixed to the peripheral wall 23, the XYZ stage 31 is operated to bring the probes 53 of the four-terminal measurement probes 18a to 18d into contact with the contact position of the sample 20 (see FIG. 9). ).

  After the measurement sample 20 is installed at the sample installation location of the plate 35 and the probe 53 of the probes 18a to 18d is brought into contact with the contact location of the sample 20, the switch of the controller is turned on and the four-terminal resistance measurement device 10 ( Start the four-terminal resistance measurement system. When the apparatus 10 is activated, an initial screen (not shown) is displayed on the display of the controller. The initial screen includes a set vacuum input area, set temperature input area, set current value input area, set voltage value input area, set energization time input area, sample name input area, sample number input area, and operator name input area. In addition to being displayed, a setting confirmation button, a clear button, and a cancel button are displayed. When the clear button is clicked, the items entered in each input area are deleted, and the input to each input area is performed again. When the cancel button is clicked, the controller is turned off without starting the apparatus 10.

  The measurer inputs the degree of vacuum in the set vacuum degree input area, inputs the temperature in the set temperature input area, and inputs the current value in the set current value input area. Enter the voltage value in the set voltage value input area and enter the energization time in the set energization time input area. Further, the sample name is input in the sample name input area, the sample number is input in the sample number input area, and the measurer name is input in the measurer name input area. When the setting confirmation button is clicked after inputting each of these items, the controller generates a unique identifier corresponding to the measurement sample 20, and sets the degree of vacuum, the setting temperature, the setting current value, the setting voltage value, the setting energization time, The sample name, sample number, and measurer name are stored in the hard disk in a state associated with the identifier of the sample 20 and the confirmation date and time, and an execution confirmation screen (not shown) is displayed on the display.

  The execution confirmation screen includes a set vacuum display area that displays the set vacuum, a set temperature display area that displays the set temperature, a set current value display area that displays the set current value, and a set voltage value display that displays the set voltage value. Area, set energization time display area that displays the set energization time, sample name display area that displays the sample name, sample number display area that displays the sample number, and operator name display area that displays the measurer name A measurement execution button, a setting change button, a return button, and a cancel button are displayed. When you click the back button, the initial screen appears on the display.

  When the set vacuum level, set temperature, set current value, set voltage value, and set energization time have already been input (stored), the initial screen displays the set vacuum level display area that displays the set vacuum level and the set temperature. Set temperature display area displaying, Set current value display area displaying set current value, Set voltage value display area displaying set voltage value, Set energization time display area displaying set energization time, Sample name input area, Sample A number input area and a measurer name input area are displayed, and a setting confirmation button, a setting change button, a clear button, and a cancel button are displayed.

  To change the set vacuum level, set temperature, set current value, set voltage value, set energization time, sample name, sample number, or measurer name, click the setting change button on the initial screen or execution confirmation screen. When the setting change button is clicked, a setting change screen (not shown) is displayed on the display. On the setting change screen, a setting vacuum level confirmation area displaying the set vacuum level, a setting vacuum level input area for entering a new set vacuum level, a setting temperature confirmation area displaying a set temperature, and a setting for entering a new set temperature Temperature input area, set current value confirmation area displaying the set current value, set current value input area for entering a new set current value, set voltage value confirmation area displaying the set voltage value, and entering a new set voltage value Set voltage value input area, set energization time confirmation area displaying set energization time, set energization time input area for entering new set energization time, sample name confirmation area displaying sample name, number confirmation area displaying sample number A measurer name confirmation area displaying the measurer name is displayed, and a change confirmation button, a clear button, and a return button are displayed. When the back button is clicked, an initial screen or an execution confirmation screen is displayed on the display.

  When changing at least one of the items, change the set vacuum level, set temperature, set current value, set voltage value, set energization time, sample name, sample number, and name of the operator in each input area. Enter it and click the Confirm Settings button. The controller updates the set vacuum degree, set temperature, set current value, set voltage value, set energization time, sample name, sample number, and measurer name to those after the change, and changes them to the identifier of the measurement sample 20 and the date and time of confirmation. Are stored in the hard disk in a state of being associated with each other, and an execution confirmation screen is displayed on the display.

Confirmation of execution when setting vacuum level, setting temperature, setting current value, setting voltage value, setting energization time, sample name, sample number, and operator name are unchanged, or when measuring after changing them Click the measurement execution button on the screen. When the measurement execution button is clicked on the execution confirmation screen, the controller activates the vacuum exhaust mechanism 15 (the turbo molecular pump 43 and the roughing pump 44). When the evacuation mechanism 15 is activated, the turbo molecular pump 43 and the roughing pump 33 exhaust the air in the internal spaces 24 and 32 of the vacuum chamber 11 and the vacuum vessel 12, and the internal spaces 24 and 32 of the vacuum chamber 11 and the vacuum vessel 12. Is gradually reduced in pressure. The controller measures the degree of vacuum in the internal spaces 24 and 32 of the vacuum chamber 11 and the vacuum vessel 12 based on the vacuum pressure output from the vacuum gauge, and the degree of vacuum is set to a set degree of vacuum (for example, 1 × 10 ⁻⁷ to 1 × 10 ⁻¹³ Pa ultra-vacuum), the outputs of the pumps 43 and 44 are adjusted so as to maintain the degree of vacuum. In the four-terminal resistance measuring device 10, the degree of vacuum in the internal spaces 24 and 32 of the vacuum chamber 11 and the vacuum vessel 12 can be adjusted in the range of 1 × 10 ⁻² to 1 × 10 ⁻¹³ Pa.

  When the set temperature of the measurement sample 20 is set to an extremely low temperature of, for example, 10 to 6 Kelvin, the controller activates the helium refrigerating mechanism 16 with the heater 17 stopped after the vacuum level reaches the set vacuum level. Let When the refrigeration mechanism 16 is activated, helium gas (refrigerant) is supplied from the helium gas relay box 51 to the helium refrigerator 46, and the helium gas is helium refrigerator 46 → outward pipe 47 → first cooling stage 48 → return pipe 49 (first pipe). 2 Cooling stage 50) circulates in the order of refrigerator 46. The controller measures the flow rate of the helium gas flowing in the forward pipe 47 based on the flow rate output from the flow meter, and keeps the flow rate of the helium gas sent from the refrigerator 46 substantially constant.

  The helium gas flowing through the outgoing pipe 47 flows into the first cooling stage 48 from the outgoing pipe 47, and the first cooling stage 48 is cooled to a cryogenic temperature by the helium gas flowing inside. The helium gas that has flowed through the first cooling stage 48 flows into the return pipe 49, then flows into the second cooling stage 50 from the return pipe 49, and the second cooling stage 50 is cooled to a cryogenic temperature by the helium gas flowing into the inside. Is done.

  The cold heat of the first cooling stage 48 is transmitted to the contact plate 37 of the measurement stage 13 that contacts (contacts) the first cooling stage 48 cooled to a very low temperature, and the contact plate 37 is cooled to a very low temperature. The cooling heat is transmitted from the contact plate 37 to the intermediate plate 36 and from the intermediate plate 36 to the sample setting plate 35, whereby the entire measurement stage 13 is cooled to a very low temperature. Furthermore, cold heat is transmitted to the measurement sample 20 fixed to the sample setting plate 35, and the sample 20 is cooled to a very low temperature.

  Cold heat of the second cooling stage 50 is transmitted to the rear end portion 40 of the shield cover 14 connected to the second cooling stage 50 cooled to an extremely low temperature, and the rear end portion 40 of the shield cover 14 is cooled to an extremely low temperature. The cooling heat is transmitted from the rear end portion 40 to the intermediate portion 39 and also transmitted from the intermediate portion 39 to the front end portion 38, whereby the entire shield cover 14 is cooled to an extremely low temperature. Further, cold heat is transmitted from the front end portion 38 of the shield cover 14 to the vicinity of the peripheral edge portion 41 of the sample setting plate 13. Although the temperature of the plate 13 cooled to an extremely low temperature may increase due to heat transmitted from the peripheral edge portion 41 of the sample setting plate 13, the vicinity of the peripheral edge portion 41 of the plate 13 is cooled by the front end portion 38 of the shield cover 14. The temperature rise of the plate 13 is prevented, the temperature of the plate 13 is kept at a substantially constant cryogenic temperature, and the temperature of the sample 20 is kept at a substantially constant cryogenic temperature.

  After the cold heat of the fixed seat 42 is transmitted to the crimp terminal 76 connected to the fixed seat 42 (the front end portion 38 of the shield cover 14) cooled to an extremely low temperature, and after being transmitted from the crimp terminal 77 to the heat transfer flexible wire 57, the cold heat is transmitted. It is transmitted from the wire 57 to the crimp terminal 76. Further, cold heat is transmitted from the crimp terminal 76 to the probe guide 54 and from the guide 54 to the probe 53, whereby the entire probe 53 is cooled to a very low temperature. When the tip 58 of the probe 53 in contact with the measurement sample 20 is at room temperature, the temperature of the sample 20 cooled to an extremely low temperature may increase due to the temperature, but the tip 58 of the probe 53 may be heated by the heat transfer flexible wire 57. Therefore, the temperature of the sample 20 is prevented from rising, and the temperature of the sample 20 is kept at a substantially constant cryogenic temperature. When the temperature output from the temperature sensor reaches the set temperature, the controller holds the flow rate of helium gas so as to hold the temperature.

The degree of vacuum of the vacuum chamber 11 reaches a set degree of vacuum (for example, a vacuum of 1 × 10 ⁻² to 1 × 10 ⁻¹³ Pa or ultra vacuum), and the temperature of the measurement sample 20 reaches a set temperature (10 to 6 Kelvin). In this case, the controller energizes the measurement sample 20 from the probe 53 of the four-terminal measurement probes 18a and 18d to the measurement sample 20 for the set energization time, and applies the voltage of the set voltage value for the set energization time. At the same time, the voltage of the sample 20 is measured by the probes 18b and 18c. The controller calculates the resistance value (volume resistivity [Ω · cm]) per unit volume of the sample 20 by the four-end needle method (four-terminal method) from the current passed through the measurement sample 20 and the measured voltage. The controller stores the calculated resistance value in the hard disk in a state associated with the identifier of the measurement sample 20 and the measurement date and time, and sets the degree of vacuum, the set temperature, the set current value, the set voltage value, and the set energization time when calculating the resistance value. The sample name, sample number, and measurer name are stored in the hard disk in a state associated with the identifier of the sample 20 and the measurement date and time.

  After calculating the resistance value, the controller displays a measurement result screen (not shown) on the display. The measurement result screen includes a date and time display area that displays the measurement date, a sample name display area that displays the name of the measurement sample, a sample number display area that displays the sample number, a measurer name display area that displays the measurer name, The resistance value display area that displays the calculated resistance value, the setting vacuum level display area that displays the set vacuum level, the set temperature display area that displays the set temperature, the set current value display area that displays the set current value, and the set voltage value A displayed set voltage value display area, a set energization time display area indicating the set energization time, and a measurement continuation button, a measurement end button, and a print button are displayed. When the print button is clicked, each item displayed on the measurement result screen is printed by the printer.

  When the measurement continuation button is clicked, the controller displays an initial screen on the display. By continuing the measurement, the resistance value of the sample 20 can be measured again by the procedure described above. When measuring the resistance value of another type of measurement sample 20 or when ending the measurement, the measurement end button is clicked. When the measurement end button is clicked, the controller displays an end confirmation button, a measurement continuation button, and a return button on the display. Clicking the back button displays the measurement result screen on the display.

  When the end confirmation button is clicked, the controller stops the helium refrigeration mechanism 16 and the vacuum exhaust mechanism 15. When the mechanisms 15 and 16 are stopped, the measurement stage 13 is at room temperature, and the internal space 24 of the vacuum chamber 11 is returned to atmospheric pressure, the controller displays a sample installation OK message, an ON switch, and an OFF switch on the display. . When the measurer measures the resistance value of the new measurement sample 20, he removes the measured sample 20 from the sample installation location of the sample installation plate 35, installs the new sample 20 at the sample installation location, and then turns on the ON switch. click. When the ON switch is clicked, an initial screen is displayed on the display, and the resistance value of a new sample 20 is measured by the procedure described above. When the OFF button is clicked, the apparatus 10 stops and the controller is turned off.

  The four-terminal resistance measuring apparatus 10 (four-terminal resistance measuring system) transmits the cold heat of the second cooling stage 50 to the heat transfer flexible wire 57 through the shield cover 14 and the probe guide by the cold heat of the wire 57 transferred to the probe guide 54. Since the temperature of the probe 53 can be lowered to a very low temperature together with 54, the temperature of the probe 53 can be lowered to a cryogenic temperature substantially the same as that of the shield cover 14. Even if the probe 53 of the probes 18a to 18d comes into contact with the measurement sample 20 installed on the measurement stage 13, the four-terminal resistance measurement device 10 is the temperature of the sample 20 cooled to an extremely low temperature by the heat of the probe 53. The resistance value of the sample 20 can be measured in a state where the temperature of the sample 20 is maintained at a predetermined extremely low temperature, and a highly reliable resistance value at a very low temperature can be measured. .

  In the four-terminal resistance measuring apparatus 10, a crimp terminal 76 attached to a tip portion 74 of a wire 57 is fixed to a probe guide 54 under the intervention of a heat transfer insulating plate 61 (sapphire) and an insulating spacer 63 (aluminum nitride). Therefore, the four-terminal measurement probes 18a to 18d and the wire 57 can be reliably insulated. In the four-terminal resistance measurement device 10, the wire 57 is not electrically connected to the probe guide 54, and the current does not fall to the ground through the wire 57, so that the current is reliably supplied from the probe 53 to the measurement sample 20. The resistance value of the sample 20 at an extremely low temperature can be measured.

  When the set temperature of the measurement sample 20 is set to a low temperature of, for example, −20 to −100 ° C., after the degree of vacuum reaches the set degree of vacuum, the controller starts the helium refrigeration mechanism 16 and starts the heater 17. Let When the refrigeration mechanism 16 is activated, helium gas (refrigerant) is supplied from the helium gas relay box 51 to the helium refrigerator 46, and the helium gas is helium refrigerator 46 → outward pipe 47 → first cooling stage 48 → return pipe 49 (first pipe). 2 Cooling stage 50) circulates in the order of refrigerator 46. The controller measures the flow rate of helium gas flowing in the outgoing pipe based on the flow rate output from the flow meter, and keeps the flow rate of helium gas sent from the refrigerator 46 substantially constant. When the heater 17 is activated, the high temperature of the heater 17 is transmitted to the sample setting plate 35 and the plate 36 is heated, and the heat of the plate 36 is transmitted from the vicinity of the plate 36 to the front end portion 38 (fixed seat 42) of the shield cover 14. The temperature of the front end portion 38 (fixed seat 42) rises.

  Similarly to the case where the set temperature of the measurement sample 20 is set to an extremely low temperature, the sample 20 is cooled by cold heat, but when the heater 17 is started, the sample setting plate 35 is heated and the front end of the shield cover 14 is heated. The temperature of the part 38 (fixed seat 42) rises. When the front end portion 38 of the shield cover 38 reaches a predetermined low temperature due to cooling by the refrigeration mechanism 16 and heating by the heater 17, the cold heat is transmitted from the front end portion 38 (fixed seat 42) to the crimp terminal 77 and heat is transmitted from the crimp terminal 77. After being transmitted to the flexible wire 57, it is transmitted from the wire 57 to the crimp terminal 76. Furthermore, cold heat is transmitted from the crimp terminal 76 to the probe guide 54 and from the guide 54 to the probe 53, whereby the entire probe 53 is cooled to a low temperature.

  Although the temperature of the plate 35 cooled to a low temperature may increase due to heat transmitted from the peripheral portion 42 of the sample setting plate 35, the vicinity of the peripheral portion 42 of the plate 35 is cooled by the front end portion 38 of the shield cover 14. Therefore, the temperature rise of the peripheral portion 42 of the plate 35 is prevented, the temperature of the plate 35 is kept at a substantially constant low temperature, and the temperature of the sample 20 is kept at a substantially constant low temperature. Further, when the probe 35 in contact with the measurement sample 20 is at room temperature, the temperature of the sample 20 cooled to a low temperature may increase due to the temperature, but the tip 58 of the probe 35 is transmitted from the heat transfer flexible wire 57. Therefore, the temperature of the sample 20 is prevented from rising, and the temperature of the sample 20 is kept at a substantially constant low temperature. When the temperature output from the temperature sensor reaches the set temperature, the controller maintains the flow rate of helium gas and adjusts the output of the heater 17 so as to maintain the temperature.

The degree of vacuum of the vacuum chamber 11 reaches the set degree of vacuum (1 × 10 ⁻² to 1 × 10 ⁻¹³ Pa vacuum or ultra vacuum), and the temperature of the measurement sample 20 reaches the set temperature (−20 to −100 ° C.). In this case, the controller energizes the sample 20 from the probe 53 of the four-terminal measuring probes 18a and 18d to the sample 20 for the set energization time and applies the set voltage value voltage for the set energization time. The voltage of the sample 20 is measured by the probes 18b and 18c. The controller calculates the resistance value (volume resistivity [Ω · cm]) per unit volume of the sample 20 by the four-end needle method (four-terminal method) from the current passed through the measurement sample 20 and the measured voltage. The controller stores the calculated resistance value in the hard disk in a state associated with the identifier of the measurement sample 20 and the measurement date and time, and sets the degree of vacuum, the set temperature, the set current value, the set voltage value, and the set energization time when calculating the resistance value. The sample name, sample number, and measurer name are stored in the hard disk in a state associated with the identifier of the sample 20 and the measurement date and time. The measurement procedure of the measurement sample 20 when the set temperature is set to a low temperature is the same as that of the sample 20 when the set temperature is set to a very low temperature.

  In the four-terminal resistance measurement device 10 (four-terminal resistance measurement system), the front end portion 38 (fixed seat 42) of the shield cover 14 is cooled by cooling by the refrigeration mechanism 16 and heating by the heater 17, and the cold heat at the low temperature is reduced. The temperature of the probe 53 can be lowered to the low temperature together with the guide 54 by the cold heat of the wire 57 transmitted to the heat transfer flexible wire 57 via the shield cover 14 and transmitted to the probe guide 54. The temperature can be lowered to substantially the same low temperature as that of the cover 14. Even if the probe 53 of the probes 18a to 18d comes into contact with the measurement sample 20 installed on the measurement stage 13, the four-terminal resistance measurement apparatus 10 maintains the temperature of the sample 20 cooled to a low temperature by the heat of the probe 53. The resistance value of the sample 20 can be measured in a state where the temperature of the sample 20 is kept at a predetermined low temperature without increasing, and a highly reliable resistance value at a low temperature can be measured. In the four-terminal resistance measurement device 10, the wire 57 is not electrically connected to the probe guide 54, and the current does not fall to the ground through the wire 57, so that the current is reliably supplied from the probe 53 to the measurement sample 20. The accurate resistance value of the sample 20 at a low temperature can be measured.

  When the set temperature of the measurement sample 20 is set to a high temperature of, for example, 100 to 200 ° C., after the vacuum degree reaches the set vacuum degree, the controller starts the heater 17 while the helium refrigeration mechanism 16 is stopped. . When the heater 17 is activated, the high temperature of the heater 17 is transmitted to the sample setting plate 35 to heat the plate 35, and from the vicinity of the peripheral portion 42 of the plate 35 to the front end 38 (fixed seat 42) of the shield cover 14. The temperature of the part 38 (fixed seat 42) rises. When the temperature of the front end portion 38 of the shield cover 14 is increased by heating by the heater 17, the heat is transmitted from the front end portion 38 (fixed seat 42) to the crimp terminal 77 and from the crimp terminal 77 to the heat transfer flexible wire 57. It is transmitted from the wire 57 to the crimp terminal 76. Further, the heat is transmitted from the crimp terminal 76 to the probe guide 54 and from the guide 54 to the probe 53, so that the temperature of the entire probe 53 rises.

  When the probe 53 in contact with the measurement sample 20 is at room temperature, the temperature of the sample 20 heated to a high temperature may drop due to the temperature, but the temperature of the tip 58 of the probe 53 is transmitted from the heat transfer flexible wire 57. Therefore, the temperature of the sample 20 is prevented from decreasing, and the temperature of the sample 20 is kept at a substantially constant high temperature. When the temperature output from the temperature sensor reaches the set temperature, the controller adjusts the output of the heater 17 so as to maintain the temperature.

When the vacuum degree of the vacuum chamber 11 reaches the set vacuum degree (1 × 10 ⁻² 1 × 10 ⁻¹³ Pa vacuum or ultra-vacuum) and the temperature of the measurement sample 20 reaches the set temperature (100 to 200 ° C.), The controller energizes the measurement sample 20 from the probe 53 of the four-terminal measurement probes 18a and 18d to the measurement sample 20 for the set energization time, applies the set voltage value for the set energization time, and the probe. The voltage of the sample 20 is measured by 18b and 18c. The controller calculates the resistance value (volume resistivity [Ω · cm]) per unit volume of the sample 20 by the four-end needle method (four-terminal method) from the current passed through the measurement sample 20 and the measured voltage. The controller stores the calculated resistance value in the hard disk in a state associated with the identifier of the measurement sample 20 and the measurement date and time, and sets the degree of vacuum, the set temperature, the set current value, the set voltage value, and the set energization time when calculating the resistance value. The sample name, sample number, and measurer name are stored in the hard disk in a state associated with the identifier of the sample 20 and the measurement date and time. Note that the measurement procedure of the measurement sample 20 when the set temperature is set to a high temperature is the same as that of the sample 20 when the set temperature is set to a very low temperature.

  In the four-terminal resistance measurement device 10 (four-terminal resistance measurement system), the temperature of the front end portion 38 (fixed seat 42) of the shield cover 14 rises due to heating by the heater 17, and the heat is flexibly transferred through the shield cover 14. The temperature of the probe 53 can be raised together with the guide 54 by the heat of the wire 57 transmitted to the wire 57 and transmitted to the probe guide 54. Even if the probe 53 of the probes 18a to 18d comes into contact with the measurement sample 20 installed on the measurement stage 13, the four-terminal resistance measurement apparatus 10 maintains the temperature of the sample 20 heated to a high temperature by the heat of the probe 53. Without falling, the resistance value of the sample 20 can be measured in a state where the temperature of the sample 20 is maintained at a predetermined high temperature, and a highly reliable resistance value at a high temperature can be measured. In the four-terminal resistance measurement device 10, the wire 57 is not electrically connected to the probe guide 54, and the current does not fall to the ground through the wire 57, so that the current is reliably supplied from the probe 53 to the measurement sample 20. Therefore, it is possible to measure an accurate resistance value of the sample 20 at a high temperature.

  The four-terminal resistance measurement apparatus 10 (four-terminal resistance measurement system) uses the refrigeration mechanism 16 and the heater 17 to change the temperature of the probe 53 of the measurement stage 13 and the probes 18a to 18d between high and low temperatures (very low temperature). Thus, the temperature of the measurement sample 20 can be made optimal for that of the sample 20 during resistance measurement, and the resistance of the sample 20 can be maintained while maintaining the temperature of the sample 20 to be optimal. The value can be measured. Since the four-terminal resistance measurement apparatus 10 can measure the resistance value of the sample 20 at each temperature by changing the temperature of the probe 53 of the measurement stage 13 or the probes 18a to 18d, the sample 20 due to temperature change. It is possible to measure the change in resistance value. In the four-terminal resistance measurement device 10, even if the temperature of the measurement stage 13 changes between a high temperature and a low temperature (very low temperature), the temperature of the probe 53 is also high and low (very low temperature) in accordance with that of the measurement stage 13. Therefore, the temperature change of the sample 20 when the probe 53 comes into contact with the sample 20 can be prevented, and the accurate resistance value of the sample 20 at a predetermined temperature can be measured.

DESCRIPTION OF SYMBOLS 10 Four-terminal resistance measuring apparatus 11 Vacuum chamber 12 Vacuum container 13 Measurement stage 14 Shield cover 15 Vacuum exhaust mechanism (vacuum exhaust apparatus)
16 Helium refrigeration mechanism (refrigeration equipment)
17 Heater (heating device)
18a to 18d Four-terminal measurement probe 20 Measurement sample 24 Internal space 31 XYZ stage 35 Sample installation plate 36 Intermediate plate 37 Contact plate 38 Front end portion 39 Intermediate portion 40 Rear end portion 41 Peripheral portion 42 Fixed seat 43 Turbo Molecular pump 44 Roughing pump 46 Refrigerator 47 Outward pipe 48 First cooling stage 49 Return pipe 50 Second cooling stage 53 Probe 54 Probe guide 55 Leaf spring 56 Shaft 57 Heat transfer flexible wire 59 Rear end 60 One side 61 Heat transfer insulation Plate 62 Upper surface 63 Insulating spacer 64 Rear end portion 65 Guide block 66 Screw 71 Locking seat 72 Cylinder 74 Tip portion 75 Base end portion 76 Crimp terminal 77 Crimp terminal 79 Screw 80 One surface 81 One surface 82 Inner peripheral surface 83 Outer peripheral surface

Claims (12)

A vacuum chamber in which a measurement stage to which a measurement sample can be attached and detached is installed; a vacuum exhaust device and a freezing device connected to the vacuum chamber; and a four-terminal measurement probe installed in the vacuum chamber; An apparatus is provided with an outgoing pipe that causes a predetermined refrigerant to flow out in one direction, and a first cooling that is installed at an extended end of the outgoing pipe and is cooled to a predetermined temperature by the refrigerant, and transmits the cold to the measurement stage. A stage, a return pipe connected to the first cooling stage and allowing the refrigerant to flow into the refrigeration apparatus, and a second cooling unit installed in the return pipe and cooled to a predetermined temperature by the refrigerant and transferring the cold to the measurement stage A four-terminal resistance measurement device that measures the resistance value of the sample while maintaining the vacuum state of the vacuum chamber,
The four-terminal resistance measurement device includes a shield cover that is connected to the measurement stage and the second cooling stage to surround the measurement stage, and transmits the cooling heat of the second cooling stage to the measurement stage, and the second cooling stage The tip of the heat transfer flexible wire that transmits the cold heat to the four-terminal measurement probe is connected to each four-terminal measurement probe under insulation, and the base end of the heat transfer flexible wire is connected to the shield cover A four-terminal resistance measuring device.   The measurement stage is located inside the vacuum chamber and a sample setting plate for setting the sample, a contact plate positioned on the refrigeration apparatus side and in contact with the first cooling stage, and the sample setting plate And an intermediate plate extending between the contact plate, and the shield cover includes a front end portion that surrounds a peripheral portion of the sample setting plate, a rear end portion that surrounds the contact plate, and the intermediate plate. The four-terminal resistance measuring device according to claim 1, further comprising: an intermediate portion that surrounds, wherein a base end portion of the heat transfer flexible wire is connected to a front end portion of the shield cover.   The four-terminal measurement probe includes a probe that contacts the sample, a probe guide connected to a rear end of the probe, a leaf spring connected to a rear end portion of the probe guide, and a leaf spring The heat transfer flexible wire is connected to the probe guide by a crimping terminal attached to the tip of the shaft and is connected to the probe guide, and transmits the cooling heat of the second cooling stage to the probe guide. The four-terminal resistance measuring device according to claim 2, wherein the probe is lowered to a predetermined temperature.   The probe guide is a hexahedron made of a conductive metal, and includes a heat transfer insulating plate that abuts on one surface thereof, and an insulating spacer that overlaps one surface of the heat transfer insulating plate. While one surface of the crimp terminal attached to the tip of the flexible wire is in close contact with one surface of the heat transfer insulating plate, the inner peripheral surface of the insertion hole formed in the crimp terminal contacts the outer peripheral surface of the insulating spacer, The four-terminal resistance measuring device according to claim 3, wherein the crimp terminal, the heat transfer insulating plate, and the insulating spacer are crimped and fixed to each other in a state where the crimp terminal is insulated from the probe guide.   The four-terminal resistance measuring device according to claim 4, wherein the heat transfer insulating plate is made of surface-polished sapphire, and the insulating spacer is made of aluminum nitride.   The four-terminal resistance measuring device includes a heating device that heats the sample setting plate, and the heat transfer flexible wire measures the heat at the front end of the shield cover, the temperature of which is increased by the heat transmitted from the sample setting plate. The four-terminal resistance measurement device according to claim 3, wherein the probe is raised to a predetermined temperature by being transmitted to the probe guide.   By using the refrigeration apparatus and the heating apparatus, the four-terminal resistance measurement device can change the temperature of the sample setting plate and the temperature of the probe to the minus side in the range of 273.15 to 6 Kelvin. The four-terminal resistance measurement device according to claim 6, wherein the temperature of the sample setting plate can be changed in a range of 273.15 to 473.15 Kelvin on the plus side.   The heat transfer flexible wire is made of an elastically deformable copper stranded wire, the diameter of the heat transfer flexible wire is in the range of 1 to 1.5 mm, and the length of the heat transfer flexible wire is 5 to 10 cm. The four-terminal resistance measuring device according to any one of claims 1 to 7 in the range of. In the four-terminal measurement probe installed in the vacuum chamber, equipped with a probe that measures the voltage of the sample while flowing current through the sample while contacting the measurement sample,
The probe for measuring the four terminals is connected to the rear end of the probe guide, the heat transfer flexible wire capable of elastically deforming to transmit cold or heat to the probe, the probe guide connected to the rear end of the probe, and And a shaft connected to a rear end portion of the plate spring, and a distal end portion of the heat transfer flexible wire is insulated from the probe guide by a crimp terminal attached to the distal end portion. The heat transfer flexible wire is attached to a heat transfer medium cooled or heated by a refrigeration apparatus and a heating apparatus connected to the vacuum chamber, and the cold heat of the heat transfer medium is transferred to the probe guide. By transmitting, the probe is lowered to a predetermined temperature, and the temperature of the heat transfer medium is transmitted to the probe guide, whereby the probe is Four-terminal measurement probe, characterized in that raising to a predetermined temperature.   The probe guide is a hexahedron made of a conductive metal, and includes a heat transfer insulating plate that abuts on one surface of the probe guide and an insulating spacer that overlaps the upper surface of the heat transfer insulating plate. While one surface of the crimp terminal attached to the tip of the flexible wire is in close contact with one surface of the heat transfer insulating plate, the inner peripheral surface of the insertion hole formed in the crimp terminal contacts the outer peripheral surface of the insulating spacer, The four-terminal measurement probe according to claim 9, wherein the crimp terminal, the heat transfer insulating plate, and the insulating spacer are crimped and fixed to each other with the crimp terminal insulated from the probe guide.   11. The four-terminal measurement probe according to claim 10, wherein in the four-terminal measurement probe, the heat transfer insulating plate is made of surface-polished sapphire, and the insulating spacer is made of aluminum nitride. In the four-terminal measurement probe, the heat transfer flexible wire is made of an elastically deformable copper stranded wire, the diameter of the heat transfer flexible wire is in the range of 1 to 1.5 mm, and the length of the heat transfer flexible wire is The probe for four-terminal measurement according to any one of claims 9 to 11, wherein the length is in the range of 5 to 10 cm.

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