JP2022143992A - Semiconductor testing device and semiconductor testing method - Google Patents

Abstract

To provide a semiconductor testing device and a semiconductor testing method with which it is possible to reduce a measurement error and shorten a test time in testing a semiconductor element in wafer state.SOLUTION: A test stage 71 fixes a wafer 63 in position and is electrically connected to the cathode of a semiconductor element 27 having the cathode on the reverse side and an anode and a control electrode on the surface. A thermocouple unit 77 includes a thermocouple 74 having a tip 79 that comes into contact with the test stage 71, a first dielectric 78 for fixing the thermocouple 74 in position, a conductor coating 76 for covering the first dielectric 78, and a contact coating 75 which is a second dielectric for covering the conductor coating 76. A first probe 41 connects the anode of the semiconductor element 27 and the anode of a power supply 1. A first electrode 31 comes into contact with the outer circumference of the test stage 71 and is connected to the cathode of the power supply 1 via an ammeter 11. A second electrode 31 is connected to the conductor coating 76 of the thermocouple part 77 and the cathode of the power supply 1.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a semiconductor testing apparatus and a semiconductor testing method.

The performance of semiconductor device products is guaranteed by conducting characteristic tests in the test process in the manufacturing process. In the characteristic test, high voltage or high current is applied to the semiconductor device. The characteristic test includes a test performed in the state of a module, a test performed in the state of a semiconductor element, and the like. It is preferable that the characteristic test can be performed in a wafer state in order to reduce manufacturing costs. However, electrical resistance changes depending on the degree of contact between the test stage on which the wafer is placed and the back surface of the wafer, a difference in resistance occurs in the path from the test stage to the measurement point, and parasitic capacitance occurs in the test stage. Therefore, there is a problem that the measurement error is large.

For example, Patent Literature 1 discloses a configuration for reducing the contact resistance between the test stage and the back surface of the wafer as a test method for semiconductor transistors. In Patent Document 1, the contact resistance between the test stage and the wafer back surface electrode is reduced by setting the density of suction holes provided in the test stage to 100/cm ² or more.

JP 2015-026765 A

However, the test method described in Patent Document 1 cannot reduce the parasitic capacitance of the test stage. As a result, for example, in a collector-emitter breaking current test for an IGBT (Insulated Gate Transistor), there arises a problem that the measurement error increases and the measurement time increases. That is, the parasitic capacitances of the test circuit and test stage are charged immediately after the start of the test. If the characteristics of the semiconductor element are measured while the charging current is flowing, the measurement error increases. If the characteristics of the semiconductor device are measured after the charging of the parasitic capacitance is finished, the test time will be long.

SUMMARY OF THE INVENTION Therefore, an object of the present disclosure is to provide a semiconductor testing apparatus and a semiconductor testing method capable of reducing measurement errors and shortening test time in testing semiconductor devices in a wafer state.

The present disclosure relates to a semiconductor testing apparatus for testing characteristics of semiconductor devices. A semiconductor element has a positive electrode on the back surface, a negative electrode and a control electrode on the front surface, and turns on or off according to a control signal input to the control electrode. A semiconductor testing apparatus includes a test stage that holds a wafer on which a plurality of semiconductor elements are arranged and has a positive electrode role electrically connected to the positive electrodes of the plurality of semiconductor elements, a drive circuit, a power supply, and a test stage. a thermocouple having a tip in contact with a thermocouple, a first dielectric fixing the thermocouple, a conductor coating covering the first dielectric, and a contact coating being a second dielectric covering the conductor coating A pair, an ammeter connected to the positive electrode of the power source, a first probe connecting the negative electrode of the semiconductor element and the negative electrode of the power source, and a power source contacting the outer periphery of the test stage and through the ammeter. It comprises a first electrode connected to the positive electrode, a conductor coating of the thermocouple portion, and a second electrode connected to the positive electrode of the power supply.

The present disclosure relates to a semiconductor testing apparatus for testing characteristics of semiconductor devices. A semiconductor element has a positive electrode on the back surface, a negative electrode and a control electrode on the front surface, and turns on or off according to a control signal input to the control electrode. A semiconductor testing apparatus includes a test stage that fixes a wafer on which a plurality of semiconductor elements are arranged and has a positive electrode role electrically connected to the positive electrodes of the plurality of semiconductor elements; a drive circuit; a power supply; A conductor wiring whose pressure is a vacuum pressure, a third dielectric covering the conductor wiring and in contact with the test stage, an ammeter connected to the positive terminal of the power supply, the negative terminal of the semiconductor element, and the negative terminal of the power supply are connected. a first probe that contacts the periphery of the test stage and is connected to the positive electrode of the power supply via an ammeter; a conductor wiring; and a third electrode that is connected to the positive electrode of the power supply. Prepare.

The present disclosure relates to a semiconductor testing method using a semiconductor testing apparatus for testing characteristics of semiconductor elements. A semiconductor element has a positive electrode on the back surface, a negative electrode and a control electrode on the front surface, and turns on or off according to a control signal input to the control electrode. A semiconductor testing apparatus includes a test stage serving as a positive electrode, a drive circuit, a power supply, a thermocouple having a tip contacting the test stage, a first dielectric fixing the thermocouple, and a first dielectric a thermocouple portion having a conductor coating that covers the conductor coating, a contact coating that is a second dielectric that covers the conductor coating, a conductor wiring whose internal pressure is a vacuum pressure, and a second that covers the conductor wiring and contacts the test stage 3 dielectric, an ammeter connected with the positive pole of the power supply, a first probe, a second probe, in contact with the circumference of the test stage and connected with the positive pole of the power supply through the ammeter. It comprises a first electrode, a conductor covering of the thermocouple portion, a second electrode connected to the positive electrode of the power source, and a third electrode connected to the conductor wiring and the positive electrode of the power source. A semiconductor testing method includes the steps of: fixing a wafer on which a plurality of semiconductor elements are arranged to a test stage; connecting the positive electrodes of the plurality of semiconductor elements to the test stage; connecting the negative electrodes of the semiconductor elements with a first probe; connecting the negative electrode of the power supply and connecting the control electrode of the semiconductor element and the driving circuit by a second probe; starting the supply of voltage from the power supply; parasitic capacitance of the semiconductor element; charging the parasitic capacitance of the electrical wiring connecting the probe No. 1 and the negative electrode of the power supply; and measuring the current flowing through the semiconductor element with an ammeter after charging.

The present disclosure relates to a semiconductor testing method using a semiconductor testing apparatus for testing characteristics of semiconductor elements. A semiconductor element has a positive electrode on the back surface, a negative electrode and a control electrode on the front surface, and turns on or off according to a control signal input to the control electrode. A semiconductor testing apparatus includes a test stage serving as a positive electrode, a drive circuit, a power supply, a thermocouple having a tip contacting the test stage, a first dielectric fixing the thermocouple, and a first dielectric a thermocouple portion having a conductor coating that covers the conductor coating, a contact coating that is a second dielectric that covers the conductor coating, a conductor wiring whose internal pressure is a vacuum pressure, and a second that covers the conductor wiring and contacts the test stage 3 dielectrics, an ammeter connected to the positive pole of the power supply, a center line, a double line arranged outside the center line, a triple line arranged outside the double line, and the center line a triple coaxial cable including a fourth dielectric between the doublet and the fifth dielectric between the doublet and the triplet; a first probe; and a second probe and a first electrode in contact with the outer periphery of the test stage and connected to the positive electrode of the power supply via an ammeter, a conductor coating of the thermocouple part, and a second electrode connected to the positive electrode of the power supply, A conductor wiring and a third electrode connected to the positive electrode of the power supply are provided. The positive electrode of the power supply is connected through the ammeter, the fifth electrode connected with the first end of the centerline of the triaxial cable, the centerline, and the sixth electrode connected with the second end of the centerline, through the semiconductor element connected to the positive pole of The positive pole of the power supply is connected to the second electrode through the seventh electrode connected with the first end of the double wire of the triaxial cable, the double wire, and the eighth electrode connected with the second end of the double wire. and the third electrode. A semiconductor testing method includes steps of fixing a wafer on which a plurality of semiconductor elements are arranged on a test stage, connecting the positive electrodes of the plurality of semiconductor elements to the test stage, connecting the negative electrodes of the semiconductor elements with a first probe, connecting to the negative pole of a power supply through a ninth electrode connected to the first end of the triple line of the triple coaxial cable, the triple line, and a tenth electrode connected to the second end of the triple line; connecting the control electrode of the semiconductor element and the drive circuit with the second probe; starting the supply of voltage from the power supply; connecting the parasitic capacitance of the semiconductor element and the first probe to the negative electrode of the power supply; and measuring the current flowing through the semiconductor element with an ammeter after charging.

Advantageous Effects of Invention According to the present disclosure, it is possible to reduce measurement errors and shorten test time in testing semiconductor devices in a wafer state.

1 is a diagram showing an example of a configuration of a semiconductor testing apparatus according to Embodiment 1; FIG. 2 is a diagram showing an example of the voltage of the power supply 1 and the current value of the ammeter 11 when the switch 101 is opened in FIG. 1. FIG. 2 is a diagram showing an example of the voltage of the power supply 1 and the current value of the ammeter 11 when the switch 101 in FIG. 1 is closed; FIG. FIG. 10 is a diagram showing another example of the configuration of the semiconductor testing apparatus according to the first embodiment; 4 is a flow chart showing a procedure of a semiconductor testing method according to Embodiment 1; FIG. 10 is a diagram showing an example of the configuration of a semiconductor testing apparatus according to a second embodiment; FIG. 10 is a flow chart showing the procedure of a semiconductor testing method according to Embodiment 2; FIG. 11 is a diagram showing an example of the configuration of a semiconductor testing apparatus according to a third embodiment; FIG. 10 is a flow chart showing a procedure of a semiconductor testing method in Embodiment 3;

Hereinafter, embodiments will be described in detail with reference to the drawings. In the following description, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

Embodiment 1.
FIG. 1 is a diagram showing an example of a configuration of a semiconductor testing apparatus according to Embodiment 1. FIG. In the following, a test of collector-emitter breaking current (hereinafter referred to as leakage current), which is a typical high voltage test, will be described as an example.

Referring to FIG. 1, this semiconductor test apparatus includes a test stage 71, a first probe 41, a second probe 42, a drive circuit 2, a power supply 1, an ammeter 11, a first electrode 31 , a second electrode 32 and a third electrode 33 .

A power supply 1 supplies a DC voltage.

A test stage 71 fixes the wafer 63 . A plurality of semiconductor elements are arranged on the wafer 63 . Any self arc-extinguishing semiconductor element can be used as the semiconductor element. All the semiconductor elements arranged on the wafer 63 or a portion of all the semiconductor elements are sampled and inspected. The semiconductor element 27 represents a plurality of arranged semiconductor elements.

The semiconductor element 27 has a positive electrode on the back surface and a negative electrode and a control electrode on the front surface. Semiconductor element 27 is turned on or off according to a control signal input from drive circuit 2 to the control electrode. For example, when the semiconductor element 27 is a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), the positive electrode means a drain electrode, the negative electrode means a source electrode, and the control electrode means a gate electrode. When the semiconductor element 27 is an IGBT, the positive electrode means a collector electrode, the negative electrode means an emitter electrode, and the control electrode means a gate electrode.

In the semiconductor element 27, current flows from the positive electrode on the back surface to the negative electrode on the front surface. In order to conduct such a characteristic test of the semiconductor element 27 in the state of the wafer 63, the negative electrode (emitter in the case of IGBT) on the surface of the semiconductor element 27 and the negative electrode of the power supply 1 are connected to each other by a needle-shaped first probe 41. are electrically connected by A control electrode (gate in the case of IGBT) on the surface of the semiconductor element 27 and the driving circuit 2 of the semiconductor testing device are electrically connected by a needle-shaped second probe 42 . FIG. 1 shows a state in which the first probe 41 and the second probe 42 are connected to the semiconductor element 27 when the subject is the semiconductor element 27 .

The positive electrode (collector in the case of IGBT) on the back surface of the semiconductor element 27 is electrically directly connected to the test stage 71 (conductor) that serves as the positive electrode.

The test stage 71 is a conductor that plays the role of positive electrode. A vacuum pump is used to fix the wafer 63 to the test stage 71 . A conductive wiring 72 is provided on the surface of the test stage 71 to connect with a vacuum pump (not shown). The wafer 63 is sucked onto the test stage 71 by the pressure difference between the vacuum pressure and the atmospheric pressure by using a vacuum pump to reduce the pressure inside the conductor wiring 72 to a vacuum pressure. A third dielectric 73 such as resin covers the conductor wiring 72 to insulate the conductor wiring 72 from the test stage 71 . A third dielectric 73 contacts the test stage 71 .

A second capacitor 92 is the parasitic capacitance of the third dielectric 73 . Since a potential difference occurs between the test stage 71 and the conductor wiring 72 through the ground of the vacuum pump, a current flows to charge the second capacitor 92 immediately after the start of the leak test. Therefore, an accurate leakage current cannot be measured until after the charging of the second capacitor 92 is completed. If the conductor wiring 72 has the same potential as the test stage 71, no current flows to charge the second capacitor 92 during the leak test.

Thermocouple section 77 is connected to a thermometer (not shown) that measures the temperature of test stage 71 . The temperature of the test stage 71 is maintained at a constant temperature by a temperature controller and a thermometer (not shown). This reduces measurement errors caused by temperature differences.

The thermocouple portion 77 includes a thermocouple 74 having a tip 79 that contacts the test stage 71, a first dielectric 78 that secures the thermocouple 74, a conductor coating 76 covering the first dielectric 78, a conductor coating and a second dielectric contact coating 75 covering 76 . A conductor coating 76 is arranged inside the contact coating 75 . A first dielectric 78 is disposed inside the conductor coating 76 . Thermocouples are typically drilled and inserted into the test stage 71 . In order for the thermocouple to accurately measure the temperature of test stage 71, tip 79 preferably contacts test stage 71 and does not move. Therefore, the hole is filled with heat dissipation grease or the like, and the thermocouple 74 is inserted.

Tip 79 of thermocouple 74 contacts test stage 71 . Thermocouple 74 is connected to a thermometer (not shown). Resin is generally used for the contact coating 75 . A third capacitor 93 is the sum of the parasitic capacitances of the contact coating 75, the air between the contact coating 75 and the test stage 71, and the thermal grease. Since the potential of the thermocouple 74 is different from the potential of the test stage 71, a current flows to charge the third capacitor 93 immediately after the start of the leak test. Therefore, until the charging of the third capacitor 93 is completed, the leak current cannot be measured accurately. If the conductor coating 76 is at the same potential as the test stage 71, no current will flow to charge the third capacitor 93 during the leak test.

Ammeter 11 is connected to the positive electrode of power supply 1 .

The first electrode 31 contacts the periphery of the test stage 71 . The first electrode 31 is connected to the positive electrode of the power supply 1 via the ammeter 11 . The first electrode 31 functions as a voltage supply point to the test stage 71 . The positive electrode of the power supply 1 and the positive electrode of the semiconductor element 27 are electrically connected through the first electrode 31 .

The first probe 41 electrically connects the positive pole of the power supply 1 to the negative pole of the power supply 1 via the ammeter 11 , the first electrode 31 and the semiconductor element 27 . A first capacitor 91 is a parasitic capacitance of the electrical wiring that connects the first probe 41 and the negative electrode of the power supply 1 .

The second electrode 32 is electrically connected to the conductor coating 76 of the thermocouple portion 77 and the positive electrode of the power supply 1 .

The third electrode 33 is electrically connected to the conductor wiring 72 and the positive electrode of the power supply 1 .

The switch 101 controls conduction between the positive electrode of the power supply 1 and the second electrode 32 and the third electrode 33 .

By arbitrarily moving the test stage 71 , the needle-shaped first probes 41 and second probes 42 can be brought into electrical contact with arbitrary semiconductor elements on the wafer 63 . Alternatively, by fixing the test stage 71 and moving the first probes 41 and the second probes 42, the first probes 41 and the second probes 42 are electrically connected to arbitrary semiconductor elements on the wafer 63. may be accessible. Alternatively, the test stage 71, the first probe 41, and the second probe 42 may be arbitrarily moved. In the following description, the structure is such that the test stage 71 can move arbitrarily.

When measuring the leakage current of the semiconductor element 27 , the drive circuit 2 applies a voltage to the control electrode of the semiconductor element 27 through the second probe 42 to turn off the semiconductor element 27 . The first probe 41 is brought into contact with the negative electrode on the surface of the semiconductor element 27, and a high voltage such as 1500 V is applied from the power source 1. FIG. By measuring the current with the ammeter 11, the leakage current of the semiconductor element 27 can be measured.

FIG. 2 is a diagram showing an example of the voltage of the power supply 1 and the current value of the ammeter 11 when the switch 101 is opened in FIG. FIG. 3 is a diagram showing an example of the voltage of the power supply 1 and the current value of the ammeter 11 when the switch 101 is closed in FIG. 2 and 3, the horizontal axis is time.

Referring to FIG. 2, a method of measuring collector-emitter breaking current (also called leakage current), which is a general high voltage test, when switch 101 is open will be described.

As shown in FIG. 2, if switch 101 has been released, the test begins at time t0.

At time t1, the power supply 1 applies a constant voltage to the semiconductor device. For example, 1500V or the like is applied. The voltage of the power supply 1 is applied between the collector and the emitter of the semiconductor element 27, and a leakage current flows and a charging current for charging the first capacitors 91, 92, 93 flows. Although not shown, the semiconductor element 27 also has a parasitic capacitance, and a current for charging the parasitic capacitance of the semiconductor element 27 also flows. The peak value of charging current is i3.

At time t3, the charging of the first capacitors 91, 92, 93 and the parasitic capacitance of the semiconductor element 27 is completed.

The current measured by the ammeter 11 during the period from time t3 to time t6 is the leakage current i1 of the semiconductor element 27. FIG.

In order to obtain a stable measured value, a method of measuring multiple times and obtaining an average value is adopted. When measuring minute currents such as leakage currents, measurement errors occur due to external noise and power supply noise. In order to reduce external noise, measures such as covering a DUT (Device Under Test) with a metal case connected to GND are sometimes taken. Furthermore, in order to reduce power supply noise, a method of averaging by PLC (Power Line Cycle) is adopted. That is, the measurement is repeated in a period of integral multiples of one cycle of the power supply frequency (50 Hz: 20 ms, 60 Hz: 16.7 ms), and the average value is obtained.

The time Td from time t3 to time t6 is the sum of the time from time t3 when the parasitic capacitances of the first capacitors 91, 92, 93 and the semiconductor element 27 are completely charged until the measured value is stabilized, and an integral multiple of the PLC. becomes. Td is generally several hundred μs.

Even if the above averaging is performed, when the measurement is started from time t1 in order to shorten the test time, the first capacitors 91, 92, 93 and the parasitic capacitance of the semiconductor element 27 are charged to the measured value. Since the current is included, the measurement error becomes large.

When the measurement is completed, the voltage of power supply 1 is turned off at time t6. Since the charges accumulated in the first capacitors 91, 92, 93 and the parasitic capacitance of the semiconductor element 27 are discharged, a large current flows.

At time t7, the test ends when the discharge current stops flowing. When the measurement of the next semiconductor element is started before the discharge current has completely flown, the first capacitors 91, 92, 93 are connected at the moment the semiconductor element and the first probe 41 and the second probe 42 come into contact with each other. , a large current flows due to the charge accumulated in the semiconductor element 27, and there is a possibility that the next semiconductor element may be damaged.

With reference to FIG. 3, a method of measuring collector-emitter breaking current (also referred to as leakage current), which is a general high voltage test, when switch 101 is conducting will be described.

At time t0, the test is started.

At time t1, the power supply 1 applies a constant voltage to the semiconductor device. For example, 1500V or the like is applied. A voltage of the power supply 1 is applied between the collector and the emitter of the semiconductor element 27, and a leakage current flows and a charging current for charging the first capacitor 91 flows. Although not shown, the semiconductor element 27 also has a parasitic capacitance, and a current for charging the parasitic capacitance of the semiconductor element 27 also flows. The peak value of charging current is i2.

Here, since the conductor wiring 72 is connected to the positive electrode of the power source 1 through the third electrode 33, both sides of the third dielectric 73 have the same potential. Therefore, no current flows to charge the second capacitor 92 which is the parasitic capacitance of the third dielectric 73 . Since the conductor coating 76 of the thermocouple portion 77 is electrically connected to the positive electrode of the power supply 1 through the second electrode 32, both sides of the contact coating 75, which is the second dielectric, have the same potential. Therefore, no current flows to charge the third capacitor 93 which is the parasitic capacitance of the contact coating 75 .

The peak value of charging current is i2. Since i2 is smaller than i3, the charging time is also shortened. Therefore, charging is completed at time t2 earlier than time t3. The current measured by the ammeter 11 during the period from time t2 to time t5 is the leakage current i1 of the semiconductor element 27. FIG.

When the measurement is completed, the voltage of power supply 1 is turned off at time t5. Since the charges accumulated in the first capacitor 91 and the parasitic capacitance of the semiconductor element 27 are discharged, a large current flows.

At time t8, the test ends when the discharge current stops flowing. When the measurement of the next semiconductor element is started before the discharge current has completely flowed, the first capacitor 91 and the semiconductor element are connected at the moment the semiconductor element and the first probe 41 and the second probe 42 come into contact with each other. The electric charge accumulated in 27 causes a large current to flow, which may damage the next semiconductor element. The measurement can be finished at time t8, which is earlier than time t7.

As described above, turning on the switch 101 reduces the charging current flowing through the semiconductor element 27 to be measured and the parasitic capacitance, thereby reducing the measurement error and shortening the test time. Furthermore, since the charging current flowing through the semiconductor element 27 is reduced, measurement errors caused by heat generation of the semiconductor element 27 can also be reduced.

FIG. 4 is a diagram showing another example of the configuration of the semiconductor testing apparatus according to the first embodiment.

In the configuration of FIG. 1, switch 101 was provided and turned on to reduce measurement error and shorten test time. In the configuration of FIG. 4, switch 101 is not provided. This configuration can also achieve the same effect as in FIG.

FIG. 5 is a flow chart showing the procedure of the semiconductor testing method according to the first embodiment.

In step S01, the semiconductor testing apparatus of the present embodiment and semiconductor element 27 are connected. That is, the needle-shaped first probe 41 connects the negative electrode of the semiconductor element 27 and the negative electrode of the power source 1 . A needle-shaped second probe 42 connects the control electrode of the semiconductor element 27 and the drive circuit 2 .

In step S<b>02 , the power supply 1 of the semiconductor testing apparatus starts applying the voltage of the power supply 1 to the semiconductor element 27 .

In step S03, a charging current for charging the first capacitor 91 and a charging current for charging the parasitic capacitance of the semiconductor element 27 flow.

In step S04, after the charging of the first capacitor 91 and the charging of the parasitic capacitance of the semiconductor element 27 are completed, the ammeter 11 measures the leakage current of the semiconductor element 27. FIG.

In step S05, if the measured value satisfies the test standard, the process proceeds to step S06, and if the measured value does not satisfy the test standard, the process proceeds to step S07. Leakage current test standards are determined for semiconductor devices. This is because defects such as process defects are suspected when they are larger than the test standard.

In step S06, it is judged as a pass. In step S07, it is judged as failure. As a method for recording the test results, a method of electronically recording the address of the semiconductor element on the wafer, the measured value, and pass/fail, or a method of directly marking the semiconductor element with ink or the like can be used.

When the test is completed, the connection between the semiconductor testing apparatus and the semiconductor element 27 is released in step S08.

In step S<b>09 , the test stage 71 moves, and the semiconductor device 27 to be measured next moves under the first probe 41 .

The processing of steps S01 to S09 is repeated until all semiconductor devices 27 on wafer 63 are measured. Alternatively, in the case of a sampling test, only semiconductor devices at predetermined locations are measured.

As described above, according to the semiconductor testing apparatus and the semiconductor testing method in the first embodiment, by reducing the charging current of the parasitic capacitance of the semiconductor testing apparatus, in a high voltage test such as collector-emitter cutoff current, Measurement errors can be reduced and test times can be shortened. Furthermore, since the charging current flowing through the semiconductor element 27 is reduced, measurement errors caused by heat generation of the semiconductor element 27 can also be reduced.

Embodiment 2.
FIG. 6 is a diagram showing an example of the configuration of the semiconductor testing apparatus according to the second embodiment.

The semiconductor testing apparatus of the second embodiment includes a fourth electrode 34 in addition to the constituent elements of the semiconductor testing apparatus of the first embodiment.

A fourth electrode 34 contacts the outer circumference of the test stage 71 . A fourth electrode 34 is electrically connected to the positive electrode of the power supply 1 . The fourth electrode 34 is generally called a sense terminal. An ammeter 11 is arranged on the path from the positive electrode of the power supply 1 to the first electrode 31 . The resistance of the ammeter 11 is generally several kΩ in the range for measuring μA. For an applied voltage of 1500 V, an ammeter resistance of 5 kΩ, and a measured leakage current of 100 μA, the voltage drop across the ammeter 11 is 0.75 V. A fourth electrode 34 is provided to compensate for this voltage drop. That is, the power supply 1 detects that the potential of the test stage 71 is lower than the indicated value by 0.75 V through the fourth electrode 34, and adjusts the potential of the test stage 71 to the indicated value. 1 increases the output voltage by 0.75V.

FIG. 7 is a flow chart showing the procedure of the semiconductor testing method according to the second embodiment.

The flowchart of FIG. 7 differs from the flowchart of FIG. 5 in that the flowchart of FIG. 7 includes step S11 between steps S02 and S03.

In step S11, the power supply 1 specifies the amount of decrease ΔV from the indicated value of the potential of the test stage 71 through the fourth electrode 34, and the power supply 1 outputs so that the potential of the test stage 71 becomes the indicated value. The voltage applied is increased by the amount of decrease ΔV.

As described above, according to the semiconductor testing apparatus and the semiconductor testing method of the second embodiment, the voltage drop due to the ammeter 11 is corrected, so measurement errors can be reduced more than the first embodiment.

Embodiment 3.
A first capacitor 91 is a parasitic capacitance of wiring that electrically connects the first probe 41 and the negative electrode of the power supply 1 . Although not shown, the wiring has a resistance component, so a potential difference is generated between the first probe 41 and the negative electrode of the power supply 1 . Therefore, in the first and second embodiments, a current flows to charge the first capacitor 91 during measurement.

FIG. 8 is a diagram showing an example of the configuration of the semiconductor testing apparatus according to the third embodiment.

The semiconductor testing apparatus of the third embodiment includes a triple coaxial cable 120 in addition to the constituent elements of the semiconductor testing apparatus of the first embodiment.

The triple coaxial cable 120 includes a centerline 151 , a double line 152 located outside the centerline 151 , and a triple line 153 located outside the double line 152 . Triaxial cable 120 further includes a fourth dielectric 117 for insulation disposed between centerline 151 and double line 152 and between double line 152 and triple line 153. and a fifth dielectric 118 for electrical insulation.

The positive electrode of the power supply 1 is connected to the ammeter 11 and the fifth electrode 111 connected to the first end of the center line 151 of the triple coaxial cable 120, the center line 151, and the second end of the center line 151. It is electrically connected to the positive electrode of the semiconductor element 27 through the electrode 112 of 6 .

The positive electrode of the power supply 1 is the seventh electrode 113 connected to the first end of the double wire 152 of the triple coaxial cable 120, the double wire 152, and the eighth electrode 113 connected to the second end of the double wire 152. is electrically connected to the second electrode 32 and the third electrode 33 through the electrode 114 of the second electrode 32 and the third electrode 33 .

The first probe 41 connects the negative electrode of the semiconductor element 27 to the first end of the triple wire 153 of the triple coaxial cable 120 , the triple wire 153 , and the third electrode of the triple wire 153 . It is electrically connected to the negative electrode of the power supply 1 through the tenth electrode 116 connected to the two terminals.

The test stage 71 and the triaxial cable 120 are arranged as close as possible. Furthermore, the power source 1 and the triple coaxial cable 120 may be arranged as close as possible. Additionally, the triple coaxial cable 120 may also be as short as possible.

Thereby, the capacitance of the first capacitor 91, that is, the parasitic capacitance of the electrical wiring connecting the first probe 41 and the negative electrode of the power supply 1 can be reduced.

When a voltage is applied from the power supply 1, no potential difference occurs in the fourth dielectric 117, so no charging current flows.

Since a potential difference substantially equal to the voltage applied by the power supply 1 is generated in the fifth dielectric 118, a charging current flows. However, since the charging current flows from the positive terminal of the power supply 1 to the negative terminal of the power supply 1 through the seventh electrode 113, the fifth dielectric 118, and the tenth electrode 116, the measured value of the ammeter 11 is not affected. .

FIG. 9 is a flow chart showing the procedure of the semiconductor testing method according to the third embodiment.

The flowchart of FIG. 9 differs from the flowchart of FIG. 7 in that the flowchart of FIG. 9 includes step S23 instead of step S03.

In step S21, the semiconductor testing apparatus of this embodiment and the semiconductor element 27 are connected. That is, the needle-shaped first probe 41 connects the negative electrode of the semiconductor element 27 to the first end of the triple line 153 of the triple coaxial cable 120 , the ninth electrode 115 , the triple line 153 , and the third line 153 . It is connected to the negative electrode of the power source 1 through the tenth electrode 116 connected to the second end of the heavy wire 153 . A needle-shaped second probe 42 connects the control electrode of the semiconductor element 27 and the drive circuit 2 .

In step S23, a charging current for charging the first capacitor 91 whose capacity is reduced and a charging current for charging the parasitic capacitance of the semiconductor element 27 flow. At the same time, a charging current flows to charge the parasitic capacitance of the fifth dielectric 118 .

After that, in step S04, after the charging of first capacitor 91 and the charging of the parasitic capacitance of semiconductor element 27 are completed, ammeter 11 measures the leakage current of semiconductor element 27 as in the first and second embodiments. Measure the current. There is no need to wait for the parasitic capacitance of the fifth dielectric 118 to charge. This is because this charging current does not affect the measured value of the ammeter 11 .

In the present embodiment, the charging current peak is smaller than the charging current peak i2 shown in FIG. 3, and the time at which the charging current ends is earlier than time t2 shown in FIG.

As described above, according to the semiconductor test apparatus and the semiconductor test method of the third embodiment, by further reducing the current that charges the parasitic capacitance of the semiconductor test apparatus, high voltage tests such as collector-emitter cutoff current can be detected. , the measurement error can be reduced and the test time can be shortened. Furthermore, since the charging current flowing through the semiconductor element 27 is reduced, it is possible to reduce measurement errors caused by heat generation of the semiconductor element.

In the present disclosure, each embodiment can be combined, modified, or omitted as appropriate within the scope of the invention.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the meaning and range of equivalents of the scope of the claims.

1 power supply 2 drive circuit 11 ammeter 27 semiconductor element 31 first electrode 32 second electrode 33 third electrode 34 fourth electrode 41 first probe 42 second probe , 63 wafer, 71 test stage, 72 conductor wiring, 73 third dielectric, 74 thermocouple, 75 coating (second dielectric), 76 conductor coating, 77 thermocouple part, 78 first dielectric, 79 tip, 91 first capacitor, 92 second capacitor, 93 third capacitor, 101 switch, 111 fifth electrode, 112 sixth electrode, 113 seventh electrode, 114 eighth electrode, 115 ninth 116 tenth electrode 117 fourth dielectric 118 fifth dielectric 120 triple coaxial cable 151 centerline 152 double line 153 triple line.

Claims (9)

A semiconductor test apparatus for testing characteristics of a semiconductor device, wherein the semiconductor device has a positive electrode on its back surface and a negative electrode and a control electrode on its front surface, and responds to a control signal input to the control electrode. on or off,
The semiconductor test equipment includes:
a test stage that fixes a wafer on which a plurality of the semiconductor elements are arranged and has a role of a positive electrode that is electrically connected to the positive electrodes of the plurality of semiconductor elements;
a drive circuit;
a power supply;
a thermocouple having a tip in contact with the test stage; a first dielectric fixing the thermocouple; a conductor coating covering the first dielectric; and a second dielectric covering the conductor coating. a thermocouple portion having a contact coating;
an ammeter connected to the positive electrode of the power supply;
a first probe connecting the negative electrode of the semiconductor element and the negative electrode of the power supply;
a first electrode in contact with the periphery of the test stage and connected to the positive electrode of the power supply through the ammeter;
A semiconductor testing device comprising: a conductor coating of the thermocouple portion; and a second electrode connected to the positive electrode of the power supply. a conductor wiring whose internal pressure is a vacuum pressure;
a third dielectric covering the conductor traces and in contact with the test stage;
2. The semiconductor testing apparatus according to claim 1, comprising said conductor wiring and a third electrode connected to a positive electrode of said power supply. A semiconductor test apparatus for testing characteristics of a semiconductor device, wherein the semiconductor device has a positive electrode on its back surface and a negative electrode and a control electrode on its front surface, and responds to a control signal input to the control electrode. on or off,
The semiconductor test equipment includes:
a test stage that fixes a wafer on which a plurality of the semiconductor elements are arranged and has a role of a positive electrode that is electrically connected to the positive electrodes of the plurality of semiconductor elements;
a drive circuit;
a power supply;
a conductor wiring whose internal pressure is a vacuum pressure;
a third dielectric covering the conductor traces and in contact with the test stage;
an ammeter connected to the positive electrode of the power supply;
a first probe connecting the negative electrode of the semiconductor element and the negative electrode of the power supply;
a first electrode in contact with the periphery of the test stage and connected to the positive electrode of the power supply through the ammeter;
A semiconductor testing device comprising the conductor wiring and a third electrode connected to the positive electrode of the power supply. 4. The semiconductor testing apparatus according to claim 1, further comprising a second probe connecting a control electrode of said semiconductor element and said drive circuit. A sense terminal in contact with the periphery of the test stage,
The power supply specifies the amount of decrease from the indicated value of the potential of the test stage through the sense terminal, and reduces the voltage output by the power supply by the amount of decrease so that the potential of the test stage becomes the indicated value. 5. The semiconductor testing device according to claim 1, wherein the semiconductor testing device is increased. a center line, a double line located outside the center line, a triple line located outside the double line, and a fourth dielectric between the center line and the double line. and a fifth dielectric between said double wire and said triple wire,
A positive electrode of the power source is connected to the ammeter, a fifth electrode connected to a first end of the centerline of the triple coaxial cable, the centerline, and a sixth electrode connected to a second end of the centerline. connected to the positive electrode of the semiconductor element through the electrode,
A positive electrode of the power source is a seventh electrode connected to the first end of the double wire of the triple coaxial cable, the double wire, and an eighth electrode connected to the second end of the double wire. connected to the second electrode and the third electrode through
The first probe includes a ninth electrode connecting the negative electrode of the semiconductor element to a first end of a triple line of the triple coaxial cable, the triple line, and a second end of the triple line. 6. The semiconductor testing apparatus according to claim 1, wherein said terminal is connected to a negative electrode of said power supply through a tenth electrode connected to said terminal. A semiconductor testing method using a semiconductor testing apparatus for testing characteristics of a semiconductor device, wherein the semiconductor device has a positive electrode on its back surface, a negative electrode and a control electrode on its front surface, and a control input to the control electrode. turn on or off depending on the signal,
The semiconductor test equipment includes:
a test stage having a positive electrode role;
a drive circuit;
a power supply;
a thermocouple having a tip in contact with the test stage; a first dielectric fixing the thermocouple; a conductor coating covering the first dielectric; and a second dielectric covering the conductor coating. a thermocouple portion having a contact coating;
a conductor wiring whose internal pressure is a vacuum pressure;
a third dielectric covering the conductor traces and in contact with the test stage;
an ammeter connected to the positive electrode of the power supply;
a first probe;
a second probe;
a first electrode in contact with the periphery of the test stage and connected to the positive electrode of the power supply through the ammeter;
a second electrode connected to the conductor coating of the thermocouple portion and the positive electrode of the power supply;
The conductor wiring and a third electrode connected to the positive electrode of the power supply,
The semiconductor testing method includes:
a step of fixing a wafer on which a plurality of the semiconductor elements are arranged to the test stage and connecting the positive electrodes of the plurality of the semiconductor elements to the test stage;
connecting the negative electrode of the semiconductor element and the negative electrode of the power supply by the first probe, and connecting the control electrode of the semiconductor element and the drive circuit by the second probe;
the power supply starting to supply voltage;
charging the parasitic capacitance of the semiconductor element and the parasitic capacitance of the electrical wiring connecting the first probe and the negative electrode of the power supply;
and measuring the current flowing through the semiconductor device with the ammeter after the charging. A semiconductor testing method using a semiconductor testing apparatus for testing characteristics of a semiconductor device, wherein the semiconductor device has a positive electrode on its back surface, a negative electrode and a control electrode on its front surface, and a control input to the control electrode. turn on or off depending on the signal,
The semiconductor test equipment includes:
a test stage having a positive electrode role;
a drive circuit;
a power supply;
a thermocouple having a tip in contact with the test stage; a first dielectric fixing the thermocouple; a conductor coating covering the first dielectric; and a second dielectric covering the conductor coating. a thermocouple portion having a contact coating;
a conductor wiring whose internal pressure is a vacuum pressure;
a third dielectric covering the conductor traces and in contact with the test stage;
an ammeter connected to the positive electrode of the power supply;
a center line, a double line located outside the center line, a triple line located outside the double line, and a fourth dielectric between the center line and the double line. and a fifth dielectric between said double wire and said triple wire;
a first probe;
a second probe;
a first electrode in contact with the periphery of the test stage and connected to the positive electrode of the power supply through the ammeter;
a second electrode connected to the conductor coating of the thermocouple portion and the positive electrode of the power supply;
The conductor wiring and a third electrode connected to the positive electrode of the power supply,
A positive electrode of the power source is connected to the ammeter, a fifth electrode connected to a first end of the centerline of the triple coaxial cable, the centerline, and a sixth electrode connected to a second end of the centerline. connected to the positive electrode of the semiconductor element through the electrode,
A positive electrode of the power source is a seventh electrode connected to the first end of the double wire of the triple coaxial cable, the double wire, and an eighth electrode connected to the second end of the double wire. connected to the second electrode and the third electrode through
The semiconductor testing method includes:
a step of fixing a wafer on which a plurality of the semiconductor elements are arranged to the test stage and connecting the positive electrodes of the plurality of the semiconductor elements to the test stage;
a ninth electrode connected by the first probe to the negative electrode of the semiconductor element with a first end of a triple line of the triple coaxial cable, the triple line, and a second end of the triple line; connecting to the negative electrode of the power supply through a tenth electrode connected to and connecting the control electrode of the semiconductor element and the drive circuit by the second probe;
the power supply starting to supply voltage;
charging the parasitic capacitance of the semiconductor element and the parasitic capacitance of the electrical wiring connecting the first probe and the negative electrode of the power supply;
and measuring the current flowing through the semiconductor device with the ammeter after the charging. The semiconductor testing device further comprises a sense terminal in contact with the periphery of the test stage,
After the power supply starts supplying voltage, the power supply identifies the amount of decrease in the potential of the test stage from the indicated value through the sense terminal, and adjusts the potential of the test stage to the indicated value. 9. The semiconductor testing method according to claim 7, further comprising the step of increasing the voltage output by said power supply by said decrease amount.

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