SYSTEM AND METHOD FOR MONITORING CHARACTERISTIC PARAMETERS OF SEMICONDUCTOR DEVICES UNDER IRRADIATION SCENARIO - Patent application

Abstract

The system relates to the fields of semiconductor irradiation and semiconductor characteristic parameter testing. The system includes a drain test unit, a gate test unit, a characteristic parameter monitoring unit, a driving unit, an information processing control unit and an information transmission unit, which are respectively provided in the irradiation protection unit a and the irradiation protection unit b, and the drain test unit and the gate test unit respectively transmit test signals to the semiconductor device under test, and monitor the change in the characteristic parameters of the semiconductor device under test under irradiation conditions through the characteristic parameter monitoring unit and the information processing control unit. [Effects] There is no need for the tester to enter and exit the room during irradiation, and it can realize remote intelligent monitoring of the characteristic parameters of multiple semiconductor devices under different irradiation conditions. It has the advantages of being simple to operate, small in volume, and capable of testing tens of thousands of devices. The test results are accurate and fast, and the operating status of the equipment can be judged.

Description

[Technical field]

[0001] The present invention relates to the technical field of semiconductor irradiation and semiconductor characteristic parameter testing, and in particular to a system and method for monitoring characteristic parameters of semiconductor devices under irradiation scenarios. [Background technology]

[0002] Third-generation semiconductor gallium nitride (GaN)-based power devices have obvious superior characteristic advantages over traditional Si-based semiconductor devices, such as a large band gap, strong breakdown field strength, and fast saturation drift velocity, and have excellent application potential in work scenarios such as high frequency, high power, high temperature and high pressure. At the same time, due to the excellent material properties, such devices have good application advantages in key fields such as aerospace, nuclear physics, national defense and military industries. However, in irradiation application scenarios such as aerospace, there are still many problems in the irradiation performance of gallium nitride power devices and the stability of their operation. For example, the devices face challenges such as performance degradation and even burnout under irradiation, and are also limited by the special irradiation environment, making it difficult to monitor the operating state and degradation status of the devices. Therefore, it is currently urgent to develop technology for monitoring the characteristic parameters of gallium nitride power devices under irradiation.

[0003] Because the irradiation test environment may cause serious harm to the human body, and the residual dose on the irradiated device may also cause harm to human health, the device under test cannot be taken out of the irradiation environment in a timely manner, which will affect related research work, resulting in problems such as low accuracy and low reliability of the test data; in order to avoid the experimental monitoring equipment being affected by the irradiation source, the monitoring equipment needs to be placed far away from the irradiation source, which limits the number of devices under test and cannot simultaneously monitor different operating states of the device, affecting the test efficiency and test accuracy; in addition, the tester cannot enter the irradiation environment in the experimental process and can only test one device under test; and the test system is complex and large in volume, which ultimately affects the test results.

[0004] In order to solve the above problems, it is urgent to design a technology for monitoring the characteristic parameters of semiconductor devices under irradiation scenarios, which can solve the difficult problems such as the inability to monitor the characteristic parameters of the semiconductor devices under test in real time at close range, the complexity of the test circuit system, and the inability of the tester to enter and exit, resulting in a small number of devices under test, low test efficiency, and low test accuracy. Summary of the Invention [Problem to be solved by the invention]

[0005] In response to the shortcomings of current irradiation monitoring technology systems, such as complicated operation, large volume, small number of test devices, low efficiency, inaccurate test results, and inaccessibility of workers, the present invention proposes a system and method for monitoring characteristic parameters of semiconductor devices under irradiation scenarios, to realize accurate and rapid monitoring of characteristic parameters of up to 10,000 devices under irradiation. [Means for solving the problem]

[0006] In order to achieve the above object, a system for monitoring characteristic parameters of a semiconductor device under irradiation scenarios designed according to the present invention is used for measuring characteristic parameters of a plurality of semiconductor devices under test, the monitoring system comprising: a drain test unit, a gate test unit, a characteristic parameter monitoring unit, a driving unit, an information processing control unit and an information transmission unit, the characteristic parameter monitoring unit including a monitoring circuit and an output circuit; The drain test unit, the gate test unit, the monitoring circuit of the characteristic parameter monitoring unit and the semiconductor device under test are disposed in an irradiation protection unit a which is covered with an outer layer of a metal material, the output circuit of the characteristic parameter monitoring unit, the driving unit and the information processing control unit are disposed in an irradiation protection unit b which is covered with an outer layer of an irradiation-resistant material, and the irradiation protection unit a and the irradiation protection unit b are both exposed to an irradiation environment and connected by a buckle; The drain test unit is connected to the drain of the semiconductor device under test, the gate test unit is connected to the gate of the semiconductor device under test, and a monitoring circuit of the characteristic parameter monitoring unit has one end connected to the drain of the semiconductor device under test and the other end connected to the source of the semiconductor device under test, and is used to transmit a test signal to the drain and gate of the semiconductor device under test and receive monitoring status information of the semiconductor device under test; The driving unit is used to drive the drain test unit and the gate test unit to start the test, and the characteristic parameter monitoring unit has a monitoring circuit that receives and amplifies monitoring status information, and then an output circuit receives it and transmits it to an information processing control unit, the information processing control unit receives the monitoring status information, forms monitoring parameters corresponding to the status of the semiconductor device under test and remotely transmits them to an information transmission unit, and the information transmission unit transmits the monitoring parameters of all the semiconductor devices under test to an external system.

[0007] In addition, the numbers of gate test units, characteristic parameter monitoring units, and semiconductor devices under test in one of the radiation protection units a are the same and are all m, m being a multiple of 10, and every 10 semiconductor devices under test are docked to the same drain test unit.

[0008] Furthermore, there are several radiation protection units a, and in each radiation protection unit a, the drains of all the semiconductor devices under test are connected in series, and the gates are connected in series.

[0009] Furthermore, the characteristic parameter monitoring unit includes two photoelectric couplers, where the monitoring circuit of the characteristic parameter monitoring unit includes a monitoring capacitor, a current amplifier and the input terminals of the two photoelectric couplers, one end of the monitoring capacitor is connected to the drain of the semiconductor device under test, and the other end is connected to the input terminals of the two opposite-direction photoelectric couplers through a current amplifier and then connected to the source of the semiconductor device under test, and the output circuit of the characteristic parameter monitoring unit includes the output terminals of the two photoelectric couplers, two latches, a red LED and a green LED; When the semiconductor device under test is turned off, the monitoring capacitor is charged to form a charging current, which passes through a current amplifier and then enters two photoelectric couplers, driving one of the photoelectric couplers and a red LED to emit light, and at the same time, a latch maintains the red LED in an emitting state; When the semiconductor device under test is short-circuited, the monitoring capacitor is discharged to form a discharge current, which passes through a current amplifier and then enters the two photoelectric couplers to drive the other photoelectric coupler and the green LED to emit light, and at the same time, the latch maintains the green LED in an emitting state.

[0010] Furthermore, the gate test unit and the drain test unit have the same structure, including a phototransistor and a PMOS tube, and when the phototransistor receives a signal, it is turned on, and the PMOS tube is turned on to output a gate voltage or a drain voltage to the semiconductor device under test.

[0011] In addition, the radiation protection unit a also includes a circuit restoration unit, the circuit restoration unit includes a microampere constant current circuit, a high-voltage electromagnetic switch and an equivalent circuit, the high-voltage electromagnetic switch has a normally closed end connected to the drain of the semiconductor device under test, a normally open end connected to the equivalent circuit, and a common end connected to the microampere constant current circuit and the drain test unit; When the information processing control unit detects that the semiconductor device under test is in an off state or a short-circuit state under irradiation conditions, the driving unit drives the circuit restoration unit to operate, thereby isolating the drain of the semiconductor device under test from the monitoring circuit and connecting the equivalent circuit to the monitoring circuit.

[0012] Further, the information processing control unit includes an FPGA chip and a Bluetooth module, and the FPGA chip controls the driving unit to send driving commands to the drain test unit, the gate test unit and the high-voltage electromagnetic switch based on the monitoring status information of the semiconductor device under test received from the latch, and the Bluetooth module remotely transmits the monitoring parameters of the semiconductor device under test to the information transmission unit, and the information transmission unit receives the monitoring parameters via the Bluetooth module, stores them locally, and transmits them to an external system via a network.

[0013] Furthermore, the driving circuit is realized by a photoelectric coupler, and the input terminal and the output terminal of the photoelectric coupler are provided in the radiation protection unit a and the radiation protection unit b respectively, both of which are located at the buckle connection part.

[0014] The invention further provides a method for monitoring characteristic parameters of a semiconductor device under an irradiation scenario, implemented on the basis of the above system, said method comprising: Step S1, in which all the semiconductor devices to be tested, the drain test unit, the gate test unit, the characteristic parameter monitoring unit, the drive unit and the information processing control unit are arranged in the irradiation protection unit a and the irradiation protection unit b, respectively, and both are placed in the irradiation chamber; Step S2 of establishing communication between the tester, the external system, and the information processing control unit by remote connection; Step S3: the tester sends a control command to the information processing control unit, the information processing control unit turns on the gate test unit and the drain test unit through the driving unit, the tester observes whether the red LED of the characteristic parameter monitoring unit is lit, if it is lit, the monitoring circuit operates normally, and then controls the information processing control unit to reset the latch, and if it is observed that the red LED is off, the irradiation source can be turned on and monitored; Step S4: input the preset drain bias voltage and gate voltage, turn on the irradiation source, the characteristic parameter monitoring unit starts to operate, and when all the semiconductor devices under test operate normally, the state of the characteristic parameter monitoring unit does not change; Step S5: if a certain semiconductor device under test is faulty under irradiation and is in off state A or short-circuit state B, the corresponding red LED or green LED is lit, at this time, the information processing control unit transmits the monitoring parameters to the information transmission unit, and then the tester checks through the external system whether the red LED or green LED displayed at the location of the corresponding semiconductor device under test is lit, and the information processing control unit selectively controls the driving circuit of the corresponding circuit restoration unit to connect the corresponding equivalent circuit to the monitoring module; and step S6 of simultaneously monitoring the operating status of all the semiconductor devices under test under the irradiation conditions, if the tester does not enter the irradiation chamber and does not touch the irradiated devices, thereby judging the irradiation resistance of the semiconductor devices under test.

[0015] Preferably, in step S1, 100 semiconductor devices to be tested are arranged in the irradiation protection unit a in a row according to a 10*10 matrix, and the 100 irradiation protection units a are placed in an irradiation chamber at the same time, and a tester detects characteristic parameters of the 10,000 semiconductor devices to be tested at the same time.

[0016] The system for monitoring the characteristic parameters of semiconductor devices under irradiation scenarios designed by the present invention realizes the connection of multiple characteristic parameter monitoring units by serially connecting multiple irradiation protection units a according to the needs of the number of semiconductor devices under test, while at the same time, the circuit complexity of the characteristic parameter monitoring unit provided in the irradiation protection unit b does not change, which makes it easy for the tester to simultaneously monitor up to 10,000 semiconductor devices under test, and solves the problem that the device cannot be replaced during irradiation, the existing monitoring system is complicated, and the number of semiconductor devices under test is small. The present invention uses the charging and discharging status of the monitoring capacitor in the monitoring circuit to monitor the operating states (off state A, short circuit state B, normal state C) of the 10,000 semiconductor devices under test, and at the same time uses a photoelectric coupler, a red LED, and a green LED to feedback the operating state, thereby improving the test efficiency.

[0017] The beneficial effects of the present invention include the following: 1. The present invention realizes electrical isolation and spatial isolation between the drain test unit, the gate test unit and the corresponding driving circuits, avoiding mutual interference, and meeting the requirements of testing semiconductor devices with different gate voltages and / or different drain voltages in practical applications.

[0018] 2. The circuit restoration unit designed by the present invention can convert any of the semiconductor devices under test in the off state or short-circuit state in the monitoring module after irradiation into the normal operating state of the circuit, and the microampere-level constant current regulator keeps the circuit current unchanged during the restoration process, thereby avoiding any impact on other normal devices under test.

[0019] 3. The characteristic parameter conversion unit designed according to the present invention can intuitively monitor the state (off state A, short circuit state B, normal state C) of the semiconductor device under test after irradiation, and transmits the change status of the characteristic parameters of the semiconductor device under test to the information transmission unit via the information processing control unit, which facilitates the tester to directly obtain the experimental data remotely and analyze the damage status of the semiconductor device under test.

[0020] 4. In order to ensure that the irradiation environment only affects the semiconductor device under test and avoid damage to the monitoring system caused by irradiation, the entire monitoring system is distributed into an irradiation protection unit a and an irradiation protection unit b, the material coated on the irradiation protection unit a prevents the impurity particles during irradiation from affecting the semiconductor device under test, and the material coated on the irradiation protection unit b prevents the internal components from being affected by the irradiation source, and different protection materials can be selected according to the type of irradiation source.

[0021] 5. The system has the advantages of simple operation, small volume, large number of tests, accurate and rapid test results, and accurate judgment of the working status of the device. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram of the overall architecture of a system for monitoring characteristic parameters of semiconductor devices under irradiation scenarios according to the present invention. [Diagram 2] FIG. 2 is a circuit structure diagram of a system for monitoring characteristic parameters of a semiconductor device under irradiation scenarios of the present invention. [Diagram 3] FIG. 2 is a schematic diagram of the circuit structure inside the radiation protection unit a. [Figure 4] FIG. 13 is a schematic diagram of the circuit structure inside the radiation protection unit b. [Diagram 5] FIG. 2 is a diagram showing the output circuit structure of the characteristic parameter monitoring unit; [Figure 6] FIG. 2 is a circuit structure diagram of a drive unit. [Figure 7] 1 is a flow chart of a method for monitoring characteristic parameters of a semiconductor device under an irradiation scenario according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in more detail with reference to the drawings and specific examples.

[0024] The system for monitoring characteristic parameters of a semiconductor device under an irradiation scenario according to the present invention includes a drain test unit, a gate test unit, a characteristic parameter monitoring unit, a driving unit, an information processing control unit and an information transmission unit, as shown in FIG.

[0025] The characteristic parameter monitoring unit includes a monitoring circuit and an output circuit, the drain test unit is connected to the drain of the semiconductor device under test, the gate test unit is connected to the gate of the semiconductor device under test, and the monitoring circuit of the characteristic parameter monitoring unit has one end connected to the drain of the semiconductor device under test and the other end connected to the source of the semiconductor device under test, and is used to respectively transmit test signals to the drain and gate of the semiconductor device under test and receive monitoring state information of the semiconductor device under test; The driving unit is used to drive the drain test unit and the gate test unit to start the test, and the characteristic parameter monitoring unit has a monitoring circuit that receives and amplifies the monitoring status information, and then an output circuit receives it and transmits it to the information processing control unit, and the information processing control unit receives the monitoring status information, converts the status situation of the corresponding semiconductor device under test into monitoring parameters and remotely transmits them to the information transmission unit, and the information transmission unit transmits the monitoring parameters of all the semiconductor devices under test to an external system. The remote computer of the tester receives the operating status information of the semiconductor device under test at the corresponding position transmitted from the information processing control unit, and displays and monitors it by the attached software.

[0026] As shown in Fig. 2, in order to protect the core circuit in the monitoring module from being affected by irradiation and ensure that the irradiation only affects the semiconductor device under test, the entire monitoring module is distributed into two irradiation protection units a and b. Each unit circuit in the irradiation protection unit a includes the semiconductor device under test, the monitoring circuit in the characteristic parameter monitoring unit, the circuit restoration unit, the drain test unit and the gate test unit, and the irradiation protection unit b includes the driving circuit of the gate and drain test units of the semiconductor device under test, the output circuit of the photoelectric coupler in the characteristic parameter monitoring unit, the driving circuit of the circuit restoration unit and the FPGA chip of the information processing control unit. The irradiation protection unit a and the irradiation protection unit b realize the modularized separation and protection of each unit in the monitoring system, reduce the volume of the monitoring system and reduce the difficulty of operation, and ensure that the irradiation only affects the semiconductor device under test.

[0027] The above monitoring system is composed of n (1, 2, 3......N) monitoring modules, each module includes 10 drain test units, 100 gate test units, 100 circuit restoration units, 100 characteristic parameter detection and conversion units, 1 information processing control unit, 1 driving unit, 1 information transmission unit, 1 radiation protection unit a and 1 radiation protection unit b. When the number of modules is 1, 1 drain power supply and 1 gate power supply are required around the radiation protection unit, and at this time, the radiation test can be performed on up to 100 semiconductor devices under test. When the number of modules is more than 1, the drain of the radiation protection unit a can be directly connected, or the gate of the radiation protection unit a can be directly connected, in this way, only one drain power supply or one gate supply power supply is added, and the operating state of 200 semiconductor devices under test irradiated with different gate voltages or / and different drain voltages can be monitored, thereby achieving the purpose of reducing the volume of the irradiation system, simplifying the circuit layout and reducing the difficulty of operation. Similarly, to monitor 10,000 semiconductor devices, it is sufficient to arrange 100 test target semiconductor devices in a 10*10 matrix, connect the drains in series, and connect the gates in series. In this case, it is sufficient to have only 10 drain voltage sources and 10 gate voltage sources, and the difficulty and volume of the monitoring system will not increase.

[0028] When the signal of the information processing control unit is transmitted to the drain test unit and the gate test unit located in the radiation protection unit b, the corresponding driving units drive the corresponding drain and gate switches to be in an operating state, thereby realizing electrical isolation and spatial isolation in the circuit between the drain test unit, the gate test unit and their driving circuits, avoiding mutual interference, and also meeting the requirements of using the semiconductor device under test at different gate voltages or / and different drain voltages in actual practical applications.

[0029] The characteristic parameter conversion unit is used to monitor the state (off state A, short-circuit state B, normal state C) of the semiconductor device under test after irradiation, and transmits the change status of the characteristic parameters of the semiconductor device under test to the information transmission unit via the information processing control unit, which facilitates the tester to directly obtain the experimental data remotely and analyze the damage status of the semiconductor device under test.

[0030] The monitoring circuit of the characteristic parameter monitoring unit provided in the radiation protection unit (a) includes a monitoring capacitor, a current amplifier, and input terminals of two photoelectric couplers, and one end of the monitoring capacitor is connected to the drain of the semiconductor device under test, and the other end passes through the current amplifier and is connected to the input terminals of the two opposite-direction photoelectric couplers, and then is connected to the source of the semiconductor device under test.

[0031] The output circuit of the characteristic parameter monitoring unit in the radiation protection unit b includes two photoelectric coupler output terminals, two latches, a red LED and a green LED.

[0032] The circuit restoration unit includes a microampere-level constant current circuit, a high-voltage electromagnetic switch and an equivalent circuit, the high-voltage electromagnetic switch has a normally closed end connected to the drain of the semiconductor device under test, a normally open end connected to the equivalent circuit, and a common end connected to the microampere-level constant current circuit and the drain test unit, when the device under test is in an ON state C under irradiation state, the circuit restoration unit does not operate, when the device under test is in an OFF state A or a short-circuit state B under irradiation state, when the corresponding red LED or green LED is lit, the information processing control unit controls the driving circuit of the circuit restoration unit to drive the high-voltage electromagnetic switch to operate, so that the drain of the semiconductor device under test is disconnected from the monitoring circuit and the equivalent circuit is connected to the monitoring circuit, so that the entire circuit system is restored to the irradiated but not destroyed state C, and during the restoration process, the microampere-level constant current regulator keeps the circuit current unchanged.

[0033] Specifically, as shown in FIG. 3, when the gate of the semiconductor device under test DUTa1 is connected to the gate test unit and the information processing control unit transmits a drive signal for the gate test unit, the phototransistor turns on when it receives the signal, and the PMOS of the gate test unit turns on, so that it is possible to transmit an appropriate gate voltage to DUTa1. The drain of DUTa1 is connected to the normally closed end of the high-voltage electromagnetic switch, the normally open end is connected to the restoration circuit, and the constant current regulator and the drain test unit are connected to the normally closed end of the high-voltage electromagnetic switch. Similarly, when the information processing control unit transmits a drive signal for the drain test unit, the phototransistor turns on when it receives the signal, and the PMOS of the drain test unit turns on, so that it is possible to transmit an appropriate drain voltage to DUTa1. One end of the monitoring circuit is connected in parallel to the drain of DUTa1, and the other end is connected in series to the diodes of two opposite-direction photoelectric couplers (class A and class B photoelectric couplers). The normally closed end of the high voltage electromagnetic switch is connected to the restoration circuit, and then connected in parallel with the source of DUTa1 together with the monitoring circuit. DUTb1, c1...j1 and DUTa1 have the same circuit structure and connection method, DUTa2, a3...a10 are connected in series to DUTa1, DUTb2, b3...b10 are connected in series to DUTb1, ..., DUTj2, j3...j10 are connected in series to DUTj1, and the circuit structure and connection method of each series connection unit are the same.

[0034] When the semiconductor device under test is in the off state A at a certain time under illumination, the monitoring capacitor is charged to form a charging current, at this time, the charging current of the monitoring capacitor is -i1=dV1 / dC, and the voltage across the diode of the photoelectric coupler of class A after passing through the current amplifier circuit is -i1*R1 / R2, which reaches the threshold voltage, and the diode of the photoelectric coupler of class A emits light, which drives the photoelectric coupler of class A to work, while the photoelectric coupler of class B does not work, so that the red LED light of the photoelectric coupler of class A is driven to emit light. At the same time, the RS latch 1 operates to maintain the light-emitting state of the red LED light, thereby recording the off state A of the device under test and transmitting it to the information processing control unit.

[0035] When the semiconductor device is in a short-circuit state B under irradiation, the monitoring capacitor is discharged to form a discharge current, at this time, the discharge current of the monitoring capacitor is i2=dV2 / dC, and after being amplified by the amplifier, the voltage across the diode of the class B photoelectric coupler becomes i2*R1 / R2, which reaches the threshold voltage, and the diode of the class B photoelectric coupler emits light, thereby driving the class B photoelectric coupler to work, while the class A photoelectric coupler does not work, so the green LED light of the class B photoelectric coupler is driven to emit light. At the same time, the RS latch 2 operates to maintain the lighting state of the green LED light, thereby recording the short-circuit state B of the device under test and transmitting it to the information processing control unit.

[0036] As shown in FIG. 4, both the driving unit and the information processing control unit are located in the irradiation protection unit b. The driving unit, the red LED and the green LED of the photoelectric coupler and the Bluetooth module are all connected and communicated through the IO serial port and the FPGA chip. As shown in FIG. 5, the output circuit of the characteristic parameter monitoring unit includes a red LED and a green LED, and an RS latch. As shown in FIG. 6, the circuit structure of the driving unit, the gate driving circuit, the drain driving circuit and the driving circuit of the circuit restoration unit are the same. The driving circuit is realized by a photoelectric coupler, and the two parts of the photoelectric coupler are respectively provided in the irradiation protection unit a and the irradiation protection unit b, both of which are located in the buckle connection part.

[0037] The information processing control unit includes an FPGA control chip, a driving circuit of the circuit restoration unit, a driving circuit of the drain test unit and a driving circuit of the gate test unit, and a Bluetooth HC-05 module, which are all located in the radiation protection unit b to ensure that they are not affected by the radiation source, and the serial port information of the FPGA chip of the information processing control unit is connected to the remote computer of the information transmission unit through the Bluetooth HC-05 module, thereby transmitting the state changes of the device under test under irradiation, and the remote computer is remotely controlled from the outside through a network cable, a local area network, etc., thereby directly transmitting the monitored change situation of the characteristic parameters of the semiconductor device under test to the remote control personnel.

[0038] The information processing control unit receives the green LED short circuit state B and the red LED off state A of the characteristic parameter monitoring unit, and transmits them to the driving circuit of the circuit restoration unit via the serial port, disconnects the test target semiconductor in the irradiated state from the system, and connects the circuit restoration unit to the circuit, and the microampere-level constant current regulator keeps the system stable without affecting the monitoring of other test target semiconductor devices, and at the same time, the R bit potential of the RS latch does not change, so that the remote tester can monitor the damage status of the test target semiconductor online.

[0039] Based on the above system, the method for monitoring characteristic parameters of a semiconductor device under irradiation scenarios according to the present invention, as shown in FIG. Step S1: selecting an appropriate number of monitoring modules, arranging a certain number of test target semiconductor devices and drain test units, gate test units, characteristic parameter monitoring units, driving units and information processing control units in the irradiation protection unit a and the irradiation protection unit b, respectively, and placing them together in an irradiation room; Step S2 of establishing communication between the tester, the external system, and the information processing control unit by remote connection; Step S3: the tester sends a control command to the information processing control unit, the information processing control unit turns on the gate test unit and the drain test unit through the driving unit, the tester checks whether the red LED of the characteristic parameter monitoring unit is lit, if it is lit, the monitoring module works normally, then controls the information processing control unit to reset the RS latch, if it is observed that the red LED is off, the illumination source can be turned on for monitoring; Step S4: input the preset drain bias voltage and gate voltage, turn on the irradiation source, the characteristic parameter monitoring unit starts to operate, and when all the semiconductor devices under test operate normally, the state of the characteristic parameter monitoring unit does not change; Step S5: if a certain semiconductor device under test is defective under irradiation and is in off state A or in short-circuit state B, the corresponding red LED or green LED is lit, at this time, the information processing control unit transmits the monitoring parameters to the information transmission unit, and then the tester checks through an external system whether the red LED or green LED displayed at the position of the corresponding semiconductor device under test is lit; At the same time as step S5, the information processing control unit controls the driving circuit of the corresponding circuit restoration unit, and the driving circuit of the circuit restoration unit connects the corresponding equivalent circuit to avoid adverse effects on other normal semiconductor devices under test; and step S7, when the tester does not enter the irradiation chamber and does not touch the irradiated devices, simultaneously monitoring the operating status of the 10,000 semiconductor devices under test under irradiation conditions, obtaining characteristic parameter data of the semiconductor devices under irradiation, and thereby judging the irradiation resistance of the semiconductor devices under test.

[0040] Any content not described in detail herein belongs to the prior art known to those skilled in the art. Finally, it should be noted that the above specific embodiments are only for illustrating the technical solution of the present patent, and are not limiting, but although the present patent has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present patent may be modified or equivalently substituted without departing from the spirit and scope of the technical solution of the present patent, which should all be included in the scope of the claims of the present patent.

Claims

1. The test device is used to measure characteristic parameters of a plurality of semiconductor devices under test, and includes a drain test unit, a gate test unit, a characteristic parameter monitoring unit, a driving unit, an information processing control unit and an information transmission unit, the characteristic parameter monitoring unit including a monitoring circuit and an output circuit; The drain test unit, the gate test unit, the monitoring circuit of the characteristic parameter monitoring unit and the semiconductor device under test are disposed in an irradiation protection unit a which is covered with an outer layer of a metal material, the output circuit of the characteristic parameter monitoring unit, the driving unit and the information processing control unit are disposed in an irradiation protection unit b which is covered with an outer layer of an irradiation-resistant material, and the irradiation protection unit a and the irradiation protection unit b are both exposed to an irradiation environment and connected by a buckle; The drain test unit is connected to the drain of the semiconductor device under test, the gate test unit is connected to the gate of the semiconductor device under test, and a monitoring circuit of the characteristic parameter monitoring unit has one end connected to the drain of the semiconductor device under test and the other end connected to the source of the semiconductor device under test, and is used to transmit a test signal to the drain and gate of the semiconductor device under test and receive monitoring status information of the semiconductor device under test; The driving unit is used to drive the drain test unit and the gate test unit to start the test. The characteristic parameter monitoring unit has a monitoring circuit that receives and amplifies the monitoring status information, and then an output circuit that receives and transmits it to an information processing control unit. The information processing control unit receives the monitoring status information, forms monitoring parameters corresponding to the status of the semiconductor device under test, and remotely transmits them to an information transmission unit. The information transmission unit transmits the monitoring parameters of all the semiconductor devices under test to an external system. The characteristic parameter monitoring unit includes two photoelectric couplers, wherein the monitoring circuit of the characteristic parameter monitoring unit includes a monitoring capacitor, a current amplifier and the input terminals of the two photoelectric couplers, one end of the monitoring capacitor is connected to the drain of the semiconductor device under test, and the other end is connected to the input terminals of the two opposite-direction photoelectric couplers through a current amplifier and then connected to the source of the semiconductor device under test, and the output circuit of the characteristic parameter monitoring unit includes the output terminals of the two photoelectric couplers, two latches, a red LED and a green LED; When the semiconductor device under test is turned off, the monitoring capacitor is charged to form a charging current, which passes through a current amplifier and then enters two photoelectric couplers, driving one of the photoelectric couplers and a red LED to emit light, and at the same time, a latch maintains the red LED in an emitting state; When the semiconductor device under test is short-circuited, a monitoring capacitor is discharged to form a discharge current, which passes through a current amplifier and then enters two photoelectric couplers to drive the other photoelectric coupler and a green LED to emit light, and at the same time, a latch maintains the green LED in an emitting state.

2. 2. The system for monitoring characteristic parameters of semiconductor devices under irradiation scenarios as described in claim 1, wherein the number of gate test units, characteristic parameter monitoring units and semiconductor devices under test in one of the irradiation protection units a is the same and is m, m is a multiple of 10, and every 10 semiconductor devices under test are docked to the same drain test unit.

3. 3. The system for monitoring characteristic parameters of semiconductor devices under irradiation scenarios as described in claim 2, wherein there are several irradiation protection units a, and in each irradiation protection unit a, the drains of all the semiconductor devices under test are connected in series and the gates are connected in series.

4. 2. The system for monitoring characteristic parameters of semiconductor devices under irradiation scenarios as claimed in claim 1, wherein the gate test unit and the drain test unit are of the same structure, including a phototransistor and a PMOS tube, in which the phototransistor is turned on when it receives a signal, and the PMOS tube is turned on to output a gate voltage or a drain voltage to the semiconductor device under test.

5. The radiation protection unit (a) also includes a circuit restoration unit, the circuit restoration unit includes a microampere constant current circuit, a high-voltage electromagnetic switch and an equivalent circuit, the high-voltage electromagnetic switch has a normally closed end connected to the drain of the semiconductor device under test, a normally open end connected to the equivalent circuit, and a common end connected to the microampere constant current circuit and the drain test unit; 2. The system for monitoring characteristic parameters of a semiconductor device under irradiation scenarios as described in claim 1, wherein when the information processing control unit detects that the semiconductor device under test is in an off state or a short-circuit state under irradiation conditions, the driving unit drives and operates the circuit restoration unit, thereby isolating the drain of the semiconductor device under test from the monitoring circuit and connecting the equivalent circuit to the monitoring circuit.

6. 6. The system for monitoring characteristic parameters of semiconductor devices under irradiation scenarios as claimed in claim 5, wherein the information processing control unit includes an FPGA chip and a Bluetooth module, the FPGA chip controls the driving unit to send driving commands to the drain test unit, the gate test unit and the high-voltage electromagnetic switch based on the monitoring status information of the semiconductor device under test received from the latch, the Bluetooth module remotely transmits the monitoring parameters of the semiconductor device under test to the information transmission unit, and the information transmission unit receives the monitoring parameters through the Bluetooth module, stores them locally, and transmits them to an external system via a network.

7. A system for monitoring characteristic parameters of a semiconductor device in an irradiation scenario as described in claim 1, wherein the driving unit has a photoelectric coupler, and input terminals and output terminals of the photoelectric coupler of the driving unit are provided in an irradiation protection unit a and an irradiation protection unit b, respectively, and both are located at a buckle connection portion.

8. A monitoring method implemented on the basis of a system for monitoring characteristic parameters of semiconductor devices under irradiation scenarios according to any one of claims 1 to 7, comprising: Step S1, in which all the semiconductor devices to be tested, the drain test unit, the gate test unit, the characteristic parameter monitoring unit, the drive unit and the information processing control unit are arranged in the irradiation protection unit a and the irradiation protection unit b, respectively, and both are placed in the irradiation chamber; Step S2 of establishing communication between the tester, the external system, and the information processing control unit by remote connection; Step S3: the tester sends a control command to the information processing control unit, the information processing control unit turns on the gate test unit and the drain test unit through the driving unit, the tester observes whether the red LED of the characteristic parameter monitoring unit is lit, if it is lit, the monitoring circuit operates normally, and then controls the information processing control unit to reset the latch, and if it is observed that the red LED is off, the irradiation source can be turned on and monitored; Step S4: input a preset drain bias voltage and a gate voltage, turn on the irradiation source, and the characteristic parameter monitoring unit starts to operate. When all the semiconductor devices under test operate normally, the state of the characteristic parameter monitoring unit does not change; Step S5, when a certain semiconductor device to be tested is defective under irradiation and is in OFF state A or short-circuit state B, the corresponding red LED or green LED is turned on, at this time, the information processing control unit transmits the monitoring parameters to the information transmission unit, and then the tester checks through an external system whether the red LED or green LED displayed at the location of the corresponding semiconductor device to be tested is turned on; and step S6, when the tester does not enter the irradiation chamber and does not touch the irradiated devices, simultaneously monitoring the operating status of all the semiconductor devices under test under the irradiation conditions, thereby determining the irradiation resistance of the semiconductor devices under test.

9. 9. The monitoring method according to claim 8, wherein in step S1, 100 semiconductor devices under test are arranged in the irradiation protection unit a according to a 10*10 matrix, the 100 irradiation protection units a are placed in the irradiation chamber at the same time, and a tester detects the characteristic parameters of the 10,000 semiconductor devices under test at the same time.

Images