JP2008107216A - Measurement method, switch device, and measurement system including the switch device - Google Patents

Abstract

[PROBLEMS] To reduce waiting time when switching between multiple types of measurements.
A plurality of types of electrical objects to be measured connected to a first conductor of a coaxial line comprising a first conductor, a second conductor surrounding the first conductor, and a third conductor surrounding the second conductor A method for measuring characteristics by switching between a first measuring device and a second measuring device connected to a switching device, wherein the first measuring device is electrically connected to an object to be measured by the switching device. And applying a voltage for measuring the first electrical characteristic to the first conductor by the first measuring device, and applying the same potential to the second conductor as the potential of the first conductor; The step of disconnecting the first measuring device from the object to be measured by the switching device and electrically connecting the second measuring device to the object to be measured, and the second electrical characteristic of the object to be measured to the second measuring device And measuring.
[Selection] Figure 2

Description

  The present invention relates to an apparatus for measuring electrical characteristics of an object to be measured such as an integrated circuit or a discrete component, and in an environment in which a plurality of measuring apparatuses having different configurations or functions are integrated, The present invention relates to a technique for measuring characteristics.

  As an example of the prior art for measuring an object to be measured such as an integrated circuit or a discrete component, there is a semiconductor measuring device. Specific products include, for example, Agilent's products “4070 Series” and “B1500A”. A semiconductor measurement device includes a plurality of types of measurement modules for measuring characteristics of an object to be measured. Examples of the measurement module include a source / monitor unit (SMU) and a (capacitance measurement unit; CMU). These measurement modules are electrically connected to an object to be measured via a SMU CMU Unify Unit (SCUU), a switching device such as a switching matrix, a probe device, a pogo pin, or a signal cable. The SCUU has a function of switching a plurality of types of measurement modules such as SMU and CMU to connect to a device under test. Therefore, a signal transmission path shared by a plurality of types of measurement modules exists between the SCUU and the device under test.

  Reference is now made to FIG. FIG. 1 is a diagram illustrating a schematic configuration of a measurement system 10 according to the related art described above. In FIG. 1, the measurement system 10 includes a measurement device 200 and a switch device 300 that is an SCUU. In FIG. 1, a device under test 100 having at least two terminals is connected to a measuring apparatus 200 via coaxial cables 510 and 520.

  The measuring apparatus 200 includes an AC signal source 210, DC ammeters 230 and 231, an AC ammeter 260, level variable DC voltage bias sources 220, 250 and 251, and buffers 240 and 241. Inverted triangles in the figure are grounds 270 and 271 and represent a common potential, ground, or ground. In FIG. 1, a portion surrounded by a broken-line frame indicated by reference sign SMU indicates a portion corresponding to the SMU that measures the voltage-current characteristic of the device under test 100. In addition, a portion surrounded by a broken line frame indicated by reference sign CMU represents a portion corresponding to the CMU that measures the capacitance-voltage characteristic of the DUT 100.

  The switch device 300 includes single pole double throw switches 310, 320, 330, and 340. Each of the switches 310 to 340 includes one common terminal (pole, pole) and two selection terminals (throw, throw). The common terminal of each switch is given the reference symbol c. Further, the selection terminal of each switch is given a reference symbol a or b. The common terminal c is electrically connected to any one of the two selection terminals (a, b). A series circuit of an ammeter 230 and a bias source 250 is provided between the terminal a of the switch 310 and the ground 270. The buffer 240 is arranged so that the same potential as that between the ammeter 230 and the bias source 250 is applied to the terminal a of the switch 320. A series circuit of a signal source 210 and a bias source 220 is provided between the terminal b of the switch 310 and the terminal b of the switch 320. A series circuit of an ammeter 231 and a bias source 251 is provided between the terminal a of the switch 330 and the ground 271. The buffer 241 is arranged so that the same potential as the potential between the ammeter 231 and the bias source 251 is applied to the terminal a of the switch 340. An ammeter 260 is provided between the terminal b of the switch 330 and the terminal b of the switch 340. The ground 270 and the ground 271 are electrically connected inside the measuring apparatus 200.

  The coaxial cables 510 and 520 are two-wire coaxial cables, that is, coaxial cables. One end of the center conductor 511 of the coaxial cable 510 is connected to the terminal c of the switch 310, and the other end of the center conductor 511 is connected to one end of the DUT 100. One end of the outer conductor 512 of the coaxial cable 510 is connected to the terminal c of the switch 320. One end of the center conductor 521 of the coaxial cable 520 is connected to the terminal c of the switch 330, and the other end of the center conductor 521 is connected to the other end of the device under test 100. One end of the outer conductor 522 of the coaxial cable 520 is connected to the terminal c of the switch 340. The other end of the outer conductor 512 and the other end of the outer conductor 522 are connected via the switch 400. The outer conductor 512 and the outer conductor 522 are selectively conducted by the switch 400.

  In the configuration described above, when measuring the capacitance-voltage characteristic of the DUT 100, the terminal b is selected in each switch, and the switch 400 is turned on. In order to measure the capacitance-voltage characteristic, an AC signal generated by the AC signal source 210 is applied to the device under test 100, and the current flowing through the device under test 100 due to the AC signal is measured by the ammeter 260. Based on the current measurement value measured by the current 260 and the frequency and voltage amplitude value of the AC signal generated by the AC signal source 210, the capacitance value of the DUT 100 is determined. At this time, a plurality of DC voltages of different levels are generated by the bias source 220 and are individually applied to the device under test 100. Then, a capacitance value for each bias level is acquired.

  When measuring the voltage-current characteristic of the DUT 100, the terminal a is selected in each switch, and the switch 400 is turned off. In order to measure the voltage-current characteristics, the output voltages of the bias source 250 and the bias source 251 are set so that a potential difference is generated between the terminals of the device under test 100. Then, due to the difference between the output voltages, the current flowing through the DUT 100 is measured by the ammeter 230.

JP-A-2005-321379 (7th to 10th pages, 12th to 14th pages, FIG. 2, FIG. 3, FIG. 7, FIG. 8) Japanese Patent No. 3442822 (FIGS. 3 and 4) Japanese Patent Laid-Open No. 10-10170 (page 4, FIG. 1)

  Here, when switching to measurement of voltage-current characteristics after measurement of capacity-to-voltage characteristics, the waiting time associated with the switching is a problem. For example, when measuring capacitance vs. voltage characteristics, a DC bias is applied to a coaxial cable that is a common line, and charges are accumulated in the capacitance between the signal line (center conductor) and the guard (outer conductor) of the coaxial cable. The In the measurement of the voltage-current characteristic, since the accumulated charge becomes a measurement error, it is necessary to wait for the discharge of the charge until the accumulated charge becomes small enough to be ignored for measurement accuracy. For example, when the length of a coaxial cable that is a common line is about several meters, a DC bias voltage of several tens of volts is applied to the coaxial cable for measurement of capacitance vs. voltage characteristics, and the measurement accuracy is about 1 pA. When measuring DC voltage-current characteristics, a waiting time of about several tens of seconds is generated, and the length is a problem.

  In the present invention, the following is provided. In other words, the first invention provides the first conductor of the coaxial line comprising the first conductor, the second conductor surrounding the first conductor, and the third conductor surrounding the second conductor. A method of measuring a plurality of types of electrical characteristics of a connected object to be measured by switching between a first measuring device and a second measuring device connected to a switching device, wherein When one measuring device is electrically connected to the object to be measured, a voltage for measuring a first electrical characteristic of the object to be measured is applied to the first conductor by the first measuring device. And the first step of applying the same potential to the second conductor to the second conductor and the switching device to separate the first measuring device from the object to be measured. The second measuring device is electrically connected to the object to be measured. Step a, the is characterized in that includes a third step of measuring the second the electrical characteristics of the second measuring device of the object to be measured, a.

  The second invention is characterized in that, in the method of the first invention, the third step uses the second conductor as a guard for the first conductor. is there.

  Furthermore, the third invention is characterized in that, in the method of the first invention or the second invention, the first step applies a potential to the second conductor by a buffer. .

  Furthermore, according to the fourth invention, in the method of the first invention, the second invention or the third invention, the first measuring device is a capacitance measuring device, and the second measuring device is It is a voltage-current characteristic measuring device.

  The fifth invention is characterized in that, in the method of the first invention, the second invention, the third invention or the fourth invention, the object to be measured is a semiconductor element. To do.

  Furthermore, the sixth invention relates to the first conductor of the coaxial line comprising a first conductor, a second conductor surrounding the first conductor, and a third conductor surrounding the second conductor. A switch device for electrically connecting a selected one of the first measurement device and the second measurement device to the coaxial line in order to measure a plurality of types of electrical characteristics of a connected object to be measured. Applying to the first conductor a voltage for measuring the first electrical characteristic generated by the first measuring device when the first measuring device is selected; and The first measuring device is electrically connected to the coaxial line so that the same potential as the potential of the first conductor is applied to the second conductor, and the second measuring device is selected. In this case, the second measuring device is at least the first conductor and the second conductor. It is characterized in that the electrical connection to.

  Furthermore, the sixth invention relates to the device according to the fifth invention, wherein when the second measuring device is selected, the second measuring device connects the second conductor to the first conductor. The second measuring device is electrically connected to the coaxial line so that it can be used as a guard for a conductor.

  In addition, according to the eighth aspect of the invention, in the apparatus of the sixth aspect of the invention or the seventh aspect of the invention, when the first measuring device is selected, the potential applied to the second conductor is a buffer. It is characterized by being given through

  Furthermore, the ninth invention is the device of the sixth invention, the seventh invention or the eighth invention, wherein the first measuring device is a capacitance measuring device and the second measuring device is a voltage. It is a current characteristic measuring device.

  Still further, the tenth invention is the apparatus of the sixth invention, the seventh invention, the eighth invention or the ninth invention, wherein the object to be measured is a semiconductor element. It is what.

  The eleventh invention includes the switch device according to the sixth invention, the seventh invention, the eighth invention, the ninth invention, or the tenth invention, and the first measuring device. And a measurement system comprising the second measurement device.

  According to the present invention, charge accumulation in a signal transmission path between a switching device that switches a plurality of measuring devices and an object to be measured, for example, capacitance between a signal line and a guard line, or formation on a printed circuit board Accumulation of charge due to dielectric polarization or the like in the coaxial line thus formed can be reduced or eliminated, and the measurement waiting time due to discharge of the accumulated charge can be reduced or eliminated. Further, according to the present invention, the impedance of the signal transmission path between the switching device for switching a plurality of measuring devices and the device under test can be set to different values suitable for each measuring device.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The embodiment of the present invention is a measurement system 20. Reference is now made to FIG. 2, the same elements as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 2 is a diagram illustrating a schematic configuration of the measurement system 20. In FIG. 2, the measurement system 20 includes at least a measurement device 200 and a switch device 700 that is an SCUU. The measuring device 200 is a device that measures the voltage-current characteristic and the capacity-to-voltage characteristic of the device under test 100, similarly to the measuring device 200. The DUT 100 has at least two terminals. Two of the terminals of the DUT 100 are electrically connected to the switch device 700 via coaxial cables 910 and 920 for measurement.

  The switch device 700 includes switches 710, 720, 720, 740, 750, and 760 that are switching devices. Each of the switches 710 to 760 includes one common terminal and two selection terminals. The common terminal of each switch is given the reference symbol c. Further, the selection terminal of each switch is given a reference symbol a or b. The common terminal c is selectively electrically connected to any one of the two selection terminals (a, b). A series circuit of an ammeter 230 and a bias source 250 is provided between the terminal a of the switch 710 and the ground 270. The buffer 240 is arranged so that the same potential as that between the ammeter 230 and the bias source 250 is applied to the terminal a of the switch 720. A terminal a of the switch 730 is connected between the bias source 250 and the ground 270. A series circuit of a signal source 210 and a bias source 220 is provided between the terminal b of the switch 710 and the terminal b of the switch 730. The terminal b of the switch 720 is connected to the terminal b of the switch 710. A series circuit of an ammeter 231 and a bias source 251 is provided between the terminal a of the switch 740 and the ground 271. The buffer 241 is arranged so that the same potential as that between the ammeter 231 and the bias source 251 is applied to the terminal a of the switch 750. A terminal a of the switch 760 is connected between the bias source 251 and the ground 271. An ammeter 260 is provided between the terminal b of the switch 740 and the terminal b of the switch 760. The terminal b of the switch 750 is connected to the terminal b of the switch 740.

  The coaxial cables 910 and 920 are three-wire coaxial cables, that is, triaxial cables. At one end of the coaxial cable 910, that is, on the switch device 700 side, the central conductor 911 is connected to the terminal c of the switch 710, the internal conductor 912 is connected to the terminal c of the switch 720, and the external conductor 913 is connected to the terminal c of the switch 730. ing. At the other end of the coaxial cable 910, that is, on the measured object 100 side, the central conductor 911 is connected to the measured object 100, and the internal conductor 912 is opened. At one end of the coaxial cable 920, that is, on the switch device 700 side, the center conductor 921 is connected to the terminal c of the switch 740, the inner conductor 922 is connected to the terminal c of the switch 750, and the outer conductor 923 is connected to the terminal c of the switch 760. Yes. At the other end of the coaxial cable 910, that is, at the device under test 100 side, the center conductor 921 is connected to the device under test 100, and the internal conductor 922 is opened. The outer conductor 923 is connected to the outer conductor 913 at the other end of the coaxial cables 910 and 920.

  In the configuration described above, the capacity-voltage characteristic of the DUT 100 is measured by the following procedure. First, the terminal b is selected in each switch. Next, an AC signal generated by the AC signal source 210 is applied to the device under test 100, and the current flowing through the device under test 100 due to the AC signal is measured by the ammeter 260. Next, the capacitance value of the DUT 100 is calculated based on the current measurement value measured by the ammeter 260 and the frequency and voltage amplitude value of the AC signal generated by the AC signal source 210. Further, in the above capacitance measurement process, a plurality of DC voltages of different levels are generated by the bias source 220 as necessary, and are individually applied to the device under test 100. Then, the capacitance value for each bias level is measured.

  Moreover, the voltage-current characteristic of the DUT 100 is measured by the following procedure. First, the terminal a is selected in each switch. Next, the output voltages of the bias source 250 and the bias source 251 are set so that a potential difference is generated between the terminals of the DUT 100. Next, due to the difference between the output voltages, the current flowing through the DUT 100 is measured by the ammeter 230. In the current measurement process, the output voltages of the bias source 250 and the bias source 251 are set so that a plurality of potential differences of different levels are generated between the terminals of the DUT 100 as necessary. Then, the current flowing through the DUT 100 is measured by the ammeter 230 for each potential difference level.

  In the measurement of the capacitance-voltage characteristic, for example, since the terminal b of the switch 710 and the terminal b of the switch 710 have the same potential, the potential difference between the center conductor 911 and the inner conductor 912 is substantially zero or ignored. It becomes a level that can be. Therefore, the electric charge accumulated between the center conductor 911 and the inner conductor 912 is also substantially zero or negligible. As a result, it is not necessary to wait for the discharge of the electric charge accumulated in the triaxial cables 910 and 920 when measuring the voltage-current characteristic after measuring the capacitance-voltage characteristic. In addition, there is no concern that the charge affects the measurement result of the voltage-current characteristic.

  In the above embodiment, if the potential difference across the ammeter 260 is substantially zero, the switches 740 to 760 and the coaxial cable 920 may be replaced with the switches 330 to 340, the coaxial cable 520, and the switch 400. good. In this case, the connections and operations related to the switches 740 to 760 and the switch 400 are as described above. For example, the switch 400 to be replaced is connected between the outer conductors of the coaxial cable.

  In the above embodiment, the terminal b of the switch 720 is connected to the terminal b of the switch 710, and the terminal b of the switch 750 is connected to the terminal b of the switch 740. This expression is for convenience of explanation, and the technical idea of the present invention should not be limited to this. What is important is that the same potential as that of the terminal b of the switch 710 is given to the terminal b of the switch 720 and the same potential as that of the terminal b of the switch 740 is given to the terminal b of the switch 750. Therefore, for example, the terminal b of the switch 720 may be connected to the terminal b of the switch 710 via a buffer, and the terminal b of the switch 750 may be connected to the terminal b of the switch 740 via a buffer. In this case, a function as an active guard is added, and the measurement accuracy is expected to be improved.

  Further, in the above-described embodiment, the coaxial cables 910 and 920 are expressed as being independent of the switch device 700. This expression is for convenience of explanation, and the technical idea of the present invention should not be limited to this. What is important is that the section from the switches 710 to 760 to the device under test 100 has a triaxial structure as much as possible. Therefore, as long as it corresponds to the section, for example, it is desirable that the signal transmission line in the switch device 700 also has a coaxial structure, and such an aspect is also an aspect of the present invention.

  Furthermore, in the above embodiment, the switch 730 and the switch 760 can be replaced with a 1-pole 1-throw switch. In other words, each terminal a can be excluded from the switches 730 and 760. In that case, a one-pole one-throw switch is arranged so as to selectively connect the outer conductor 913 and the bias source 220 and to selectively connect the outer conductor 923 and the ammeter 260.

  Next, more detailed examples of the present invention will be described. Reference is now made to FIG. FIG. 3 is a diagram showing a configuration of a semiconductor measurement system 30 that is an embodiment of the present invention. The semiconductor measurement system 30 includes a measurement device 1000 and a connection device 2000. The measurement apparatus 1000 includes an SMU 1100, an SMU 1200, and a CMU 1300. The SMU 1100, the SMU 1200, and the CMU 1300 are controlled by the measuring device 1000 or a control device connected to the measuring device 1000.

  Each of the SMUs 1100 and 1200 is a device that includes a DC voltage source, a current source, a voltmeter, and an ammeter, and measures them in any combination. In addition, the SMUs 1100 and 1200 can be measured individually or in cooperation with each other. The SMU 1100 includes a sense terminal S1 and a force terminal F1 for Kelvin connection. The SMU 1200 includes a sense terminal S2 and a force terminal F2 for Kelvin connection. Each of terminals S1, F1, S2, and F2 has a triaxial structure (three-wire coaxial structure). That is, each of the terminals S1, F1, S2, and F2 includes a center conductor, an inner conductor that surrounds the center conductor, and an outer conductor that surrounds the inner conductor. In each of the terminals S1, F1, S2, and F2, a signal is transmitted to the center conductor, the outer shield conductor is connected to the housing ground, and the guard conductor between the center conductor and the outer shield conductor is the center conductor. A guard signal maintained at the same potential as the signal is transmitted.

  The CMU 1300 is a device that measures impedance such as capacitance, inductance, and resistance. The CMU 1300 outputs a terminal Hc for outputting a high-side current, a terminal Hp for measuring a high-side voltage, a terminal Lp for measuring a low-side voltage, and a low-side current. Terminal Lc. Terminals Hc, Hp, Lp, and Lc each have a coaxial structure (two-wire coaxial structure). That is, each of the terminals Hc, Hp, Lp, and Lc includes a center conductor and an outer conductor that surrounds the center conductor. In each terminal, a signal is transmitted to the center conductor, and the outer conductor as a shield is floated from the housing ground. The CMU 1300 includes a controller 1310 for controlling the connection device 2000. A control output of the controller 1310 is supplied to a terminal 1311. Note that the controller 1310 may be included in the measurement apparatus 1000.

  The device under test 110 is, for example, a semiconductor element formed in a TEG (Test Element Group) region provided on a silicon wafer in order to determine an optimum condition for an integrated circuit manufacturing process, or an individual element such as a transistor or a capacitor. . In the figure, the device under test 110 is connected to the connection device 2000 at two terminals among the terminals of the device under test 110 by triaxial cables 5000 and 5010. Note that a probe device and a switching matrix are arranged between the DUT 110 and the connection device 2000 as necessary.

  Triaxial cables 5000 and 5010 have respective center conductors connected to device under test 110 at the end of device under test 110 side, each external conductor is electrically connected, and each internal conductor is opened. ing.

  The connection device 2000 includes a terminal 2100 for connecting the terminal S1, a terminal 2110 for connecting the terminal F1, a terminal 2200 for connecting the terminal S2, and a terminal 2210 for connecting the terminal F2. The connection device 2000 also includes a terminal 2300 for connecting the terminal Hc, a terminal 2310 for connecting the terminal Hp, a terminal 2320 for connecting the terminal Lp, and a terminal 2330 for connecting the terminal Lc. Furthermore, the connection device 2000 includes terminals 2500 and 2510 for connecting the device under test 110. Terminals 2100, 2110, 2200, 2210, 2500, and 2510 each have a triaxial structure. Terminals 2300, 2310, 2320, and 2330 each have a coaxial structure. Further, corresponding terminals are connected by a connection 3000. The connection 3000 may be a direct connection or a connection via a cable, that is, an indirect connection.

  Reference is now made to FIG. FIG. 4 is a diagram showing an internal structure of the connection device 2000. In FIG. 4, the connection device 2000 includes switch groups T1, T2, T3, and T4 that are switching devices. In each switch group, the individual switches are 1-pole 1-throw switches. Further, in each switch group, individual switches are distinguished by reference symbols a to c attached thereto. For example, the upper switch of the switch group T1 is recognized as T1a. For example, the switch at the center of the switch group T4 is recognized as T4b.

  The center conductors of the terminals 2100 and 2110 are selectively connected to the center conductor of the terminal 2500 via the switch T1b. The inner conductor of the terminal 2110 is selectively connected to the inner conductor of the terminal 2500 via the switch T1a. The outer conductors of the terminals 2100 and 2110 are connected to the housing ground.

  The center conductors of the terminal 2200 and the terminal 2210 are selectively connected to the center conductor of the terminal 2510 via the switch T2b. The inner conductor of the terminal 2210 is selectively connected to the inner conductor of the terminal 2510 via the switch T2a. The external conductors of the terminal 2200 and the terminal 2210 are connected to the housing ground.

  The center conductors of the terminal 2300 and the terminal 2310 are selectively connected to the center conductor and the inner conductor of the terminal 2500 via the switch T3b and the switch T3c. The external conductors of the terminal 2300 and the terminal 2310 are selectively connected to the external conductor of the terminal 2500 via the switch T3a. The center conductors of terminals 2330 and 2340 are selectively connected to the center conductor and the inner conductor of terminal 2510 via switches T4b and T4c. The external conductors of terminal 2330 and terminal 2340 are selectively connected to the external conductor of terminal 2510 via switch T4a. Note that the external conductors of the terminals 2300, 2310, 2320, and 2340 are themselves floating from the housing ground.

  The outer conductors of the terminal 2500 and the terminal 2510 are connected to the housing ground.

  Although not specifically shown in the figure, the signal transmission path between the switch groups T1 and T3 and the terminal 2500 and the signal transmission path between the switch groups T2 and T4 and the terminal 2510 are as long as the design permits. It has a triaxial structure. The signal transmission path having the triaxial structure is configured by a signal line pattern formed on the printed circuit board by an etching process, a coaxial cable, or the like.

  The switch group T1 selectively connects the terminal 2100 and the terminal 2110 to the terminal 2500. The switch group T2 selectively connects the terminal 2200 and the terminal 2210 to the terminal 2510. The switch group T3 selectively connects the terminal 2300 and the terminal 2310 to the terminal 2500. Switch group T4 selectively connects terminal 2330 and terminal 2340 to terminal 2510. The switch groups T1, T2, T3, and T4 are in one of the following two states under the control of the controller 2200. At some time, the switches of the switch group T1 and the switch group T2 are on, and the switches of the switch group T3 and the switch group T4 are off. In some cases, the switches of the switch group T1 and the switch group T2 are off, and the switches of the switch group T3 and the switch group T4 are on. Controller 2200 itself operates in accordance with control information received via terminal 2400.

  In the semiconductor measurement system 30 described above, when measuring the capacitance-voltage characteristic of the DUT 110, the switch groups T1 and T2 are turned on and the switch groups T3 and T4 are turned off. The subsequent measurement procedure is as described in the above embodiment. Further, when measuring the voltage-current characteristic of the DUT 110, the switch groups T1 and T2 are turned off and the switch groups T3 and T4 are turned on. The subsequent measurement procedure is as described in the above embodiment.

  In the measurement of the capacitance-voltage characteristic, the potentials of the center conductor and the inner conductor are the same in the triaxial structure signal transmission path connected to the device under test 110. Therefore, as described in the above embodiment, when measuring the voltage-current characteristic after measuring the capacity-to-voltage characteristic, the signal transmission path between each switch group serving as a switching device and the DUT 110 is measured. There is no need to wait for the release of the accumulated charge. In addition, there is no concern that the charge affects the measurement result of the voltage-current characteristic.

  In the above embodiment, the characteristic impedance of the line used by the SMU and the characteristic impedance of the line used by the CMU are common values in the signal transmission path between each switch group serving as the switching device and the DUT 110. There may be different values. For example, the characteristic impedance of the line used by the SMU is better as the capacitance is smaller, and as a result, the characteristic impedance is better as it is larger. Therefore, for example, in the triaxial signal transmission path between each switch group and the device under test 110, the characteristic impedance of the line composed of the center conductor and the inner conductor is set to 1 kilohm, and is composed of the inner conductor and the outer conductor. If the characteristic impedance of the line to be set is 50 ohms, it is convenient in terms of measurement accuracy.

It is a figure which shows schematic structure of the measurement system 10 by a prior art. It is a figure which shows schematic structure of the measurement system 20 by this invention. It is a figure which shows the structure of the semiconductor measurement system 30 by this invention. 2 is a diagram illustrating an internal configuration of a connection device 2000 of the semiconductor measurement system 30. FIG.

Explanation of symbols

10, 20 Measurement system 30 Semiconductor measurement system 100, 110 Device under test 200 Measuring device 210, 210 AC signal source 220, 250, 251 DC voltage bias source 230, 231 DC ammeter 260 AC ammeter 240, 241 Buffer 270, 271 Ground 300, 700 Switch device 310, 320, 330, 340, 400 Switch 510, 520 Coaxial cable 511, 521 Center conductor 512, 522 External conductor 710, 720, 730, 740, 750, 760 Switch 910, 920 Triaxial Cable 911, 921 Center conductor 912, 922 Inner conductor 913, 923 Outer conductor 1000 Measuring device 1310, 2200 Controller 1311 Terminal 2000 Connection device 2100, 2110, 2200, 2210 End 2300,2310,2320,2330 terminal 2400,2500,2510 terminal 3000 connected 5000,5010 triaxial cable

Claims (11)

Plural types of objects to be measured connected to the first conductor of the coaxial line, the first conductor, the second conductor surrounding the first conductor, and the third conductor surrounding the second conductor. A method of measuring the electrical characteristics of the first measuring device and the second measuring device connected to the switching device,
When the first measuring device is electrically connected to the device under test by the switching device, a voltage for measuring the first electrical characteristic of the device under test is supplied to the first measuring device. The first step of applying to the first conductor and applying the same potential to the second conductor as the potential of the first conductor;
A second step of disconnecting the first measuring device from the device under test by the switching device and electrically connecting the second measuring device to the device under test;
A third step of measuring a second electrical characteristic of the object to be measured by the second measuring device;
A measurement method comprising:   The measurement method according to claim 1, wherein the third step uses the second conductor as a guard for the first conductor.   The measurement method according to claim 1, wherein the first step applies a potential to the second conductor by a buffer.   The method according to any one of claims 1 to 3, wherein the first measuring device is a capacitance measuring device and the second measuring device is a voltage-current characteristic measuring device.   The method according to claim 1, wherein the object to be measured is a semiconductor element. A plurality of types of objects to be measured connected to the first conductor of the coaxial line, comprising a first conductor, a second conductor surrounding the first conductor, and a third conductor surrounding the second conductor A switching device for electrically connecting a selected one of the first measuring device and the second measuring device to the coaxial line,
Applying to the first conductor a voltage for measuring the first electrical characteristic generated by the first measuring device when the first measuring device is selected; and Electrically connecting the first measuring device to the coaxial line so as to give the second conductor the same potential as the potential of the first conductor;
Electrically connecting the second measuring device to at least the first conductor and the second conductor when the second measuring device is selected;
A switch device characterized by that.   When the second measuring device is selected, the second measuring device can be used so that the second measuring device can use the second conductor as a guard against the first conductor. The switch device according to claim 6, wherein the switch device is electrically connected to a coaxial line.   3. The switch device according to claim 1, wherein when the first measuring device is selected, the potential applied to the second conductor is applied via a buffer. 4.   9. The switch device according to claim 6, wherein the first measuring device is a capacitance measuring device, and the second measuring device is a voltage-current characteristic measuring device.   The switch device according to claim 1, wherein the object to be measured is a semiconductor element. A measurement system comprising the switch device according to any one of claims 6 to 10, the first measurement device, and the second measurement device.

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