Testing equipment and method for gallium nitride power device

Abstract

The invention provides a test device and method for a gallium nitride power device, the test device comprises a power supply module, a measurement module, a detection module and a calculation module, the power supply module provides a first power supply voltage; under the control of the second driving signal, the measuring module conducts a first branch circuit used for measuring a dynamic resistance value, and under the control of the first driving signal, the gallium nitride power device to be measured is conducted; calculating a dynamic resistance value based on the first voltage and the first current measured by the detection module; under the control of a second driving signal, a second branch circuit used for measuring the threshold voltage is conducted, and in the voltage rising process of the first driving signal, based on the first power supply voltage, a second voltage between the first end and the second end of the to-be-measured gallium nitride power device and a third voltage between the control end and the second end of the to-be-measured gallium nitride power device, the threshold voltage of the to-be-measured gallium nitride power device is measured. Determining a threshold voltage; through the equipment, the dynamic resistance and the threshold voltage of the gallium nitride power device are determined at the same time, and the accuracy of test reliability is improved.

Description

Technical Field

[0001] The present application relates to the field of power electronics testing technology, and in particular to a testing device and method for gallium nitride power devices. Background Art

[0002] Among power electronic devices, gallium nitride (GaN) power devices are widely used in power electronic systems because of their superior performance over silicon (Si) and silicon carbide (SiC) devices. However, when the gate or drain of a GaN power device is subjected to electrical stress such as bias, the carriers in the gate region or channel of the GaN power device are captured by traps in the material and cannot be emitted from the traps in time, affecting the local electric field and current density of the device, thereby causing changes in key performance parameters such as threshold voltage drift and dynamic resistance of the GaN power device, resulting in low reliability of the GaN power device.

[0003] In the prior art, under circuit-level test stress bias, equipment for testing GaN power devices often uses a dual-pulse circuit, that is, applying a dual-pulse signal to the GaN power device to be tested. However, the equipment cannot simultaneously measure the threshold voltage drift and dynamic resistance of the GaN power device, thereby reducing the accuracy of device reliability assessment. Summary of the invention

[0004] The present application provides a test device and method for gallium nitride power devices, which are used to solve the problem in the prior art that the threshold voltage drift and dynamic resistance of the GaN power device cannot be measured simultaneously, thereby reducing the accuracy of device reliability evaluation.

[0005] In a first aspect, an embodiment of the present application provides a test device for a gallium nitride power device, the device comprising a power module, a measurement module, a detection module and a calculation module;

[0006] The power supply module, the measuring module and the detection module are connected in sequence to form a power circuit;

[0007] The first end of the GaN power device to be tested is electrically connected to the measurement module and the detection module respectively, the second end of the GaN power device to be tested is electrically connected to the detection module and is grounded, and the control end of the GaN power device to be tested is used to receive a first driving signal, and is turned on or off under the control of the first driving signal;

[0008] The power supply module is used to provide a first power supply voltage;

[0009] The measuring module is used to, under the control of a second driving signal, turn on a first branch for measuring a dynamic resistance value of the GaN power device to be tested, and, under the control of the second driving signal, turn off the first branch and turn on a second branch for measuring a threshold voltage of the GaN power device to be tested;

[0010] The calculation module is used to calculate the dynamic resistance value based on the first voltage and the first current measured by the detection module when the first branch is turned on and the GaN power device to be tested is turned on, and to extract the threshold voltage after determining the transfer characteristic curve of the GaN power device to be tested based on the first power supply voltage, the second voltage between the first end of the GaN power device to be tested and the second end of the GaN power device to be tested, and the third voltage between the control end of the GaN power device to be tested and the second end of the GaN power device to be tested when the second branch is turned on and the voltage of the first drive signal gradually increases.

[0011] In a possible implementation, the measuring module includes a first resistor, a first diode, a first inductor and a switch tube;

[0012] The first end of the first resistor is electrically connected to the cathode of the first diode, the first end of the first inductor and the positive electrode of the power module, and the second end of the first resistor is electrically connected to the second end of the switch tube, the first end of the GaN power device to be tested and the detection module;

[0013] An anode of the first diode is electrically connected to the second end of the first inductor and the first end of the switch tube;

[0014] The control end of the switch tube is used to receive the second driving signal.

[0015] In a possible implementation, the detection module includes a voltage clamping circuit and a second resistor;

[0016] The first end of the voltage clamping circuit is electrically connected to the second end of the switch tube, the second end of the first resistor, and the first end of the GaN power device to be tested, and the second end of the voltage clamping circuit is electrically connected to the first end of the second resistor, the second end of the GaN power device to be tested, and the ground end;

[0017] The second end of the second resistor is electrically connected to the negative electrode of the power module.

[0018] In a possible implementation, the device further includes an operational amplifier;

[0019] The non-inverting input terminal of the operational amplifier is used to receive the first driving signal, and the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the operational amplifier;

[0020] The operational amplifier is used to amplify the first drive signal to obtain a third drive signal, and provide the third drive signal to the control terminal of the GaN power device to be tested.

[0021] In a possible implementation, the power supply module includes a capacitor and a first voltage source;

[0022] The capacitor is connected in parallel with the first voltage source.

[0023] In a second aspect, the present application provides a test method for a gallium nitride power device, which is applied to any test device described in the first aspect, and the method comprises:

[0024] In the dynamic resistance value measurement stage, after the measurement module turns on the first branch for measuring the dynamic resistance value of the GaN power device to be measured under the control of the second driving signal, the GaN power device to be measured is turned on under the control of the first driving signal, and the detection module detects the first voltage and the first current; the dynamic resistance value is calculated based on the first voltage and the first current;

[0025] In the threshold voltage measurement stage, during the gradual increase of the voltage of the first drive signal, under the control of the second drive signal, the measurement module disconnects the first branch, and after the second branch for measuring the threshold voltage of the power tube device to be tested is turned on, under the control of the first drive signal, the GaN power device to be tested is turned on; based on the first power supply voltage, the second voltage between the first end of the GaN power device to be tested and the second end of the GaN power device to be tested, and the third voltage between the control end of the GaN power device to be tested and the second end of the GaN power device to be tested, the transfer characteristic curve of the GaN power device to be tested is determined, and then the threshold voltage is extracted.

[0026] In a possible implementation, before the dynamic resistance value measurement phase, a start-up phase and a freewheeling phase are also included, and the method further includes:

[0027] In the start-up phase, after the switch tube in the measurement module is turned on under the control of the second drive signal, the GaN power device to be measured is turned on under the control of the first drive signal;

[0028] In the freewheeling stage, under the control of the first driving signal, the GaN power device to be measured is disconnected, and the flowing current of the first inductor is freewheeled through the first diode in the measuring module.

[0029] In a possible implementation manner, an electrical stress stage is included before the start-up stage, and the method further includes:

[0030] In the electrical stress stage, after the switch tube in the measurement module is disconnected under the control of the second driving signal, the GaN power device to be measured is disconnected under the control of the first driving signal.

[0031] In a possible implementation, after the dynamic resistance value measurement phase and before the threshold voltage measurement phase, an interval phase is further included, and the method further includes:

[0032] In the interval stage, after the switch tube in the measurement module is turned off under the control of the second drive signal, the GaN power device to be measured is turned off under the control of the first drive signal.

[0033] In a possible implementation, in the threshold voltage measurement stage, the first drive signal is a ramp signal whose voltage increases with a positive slope, or the first drive signal is a step signal whose voltage gradually increases, or the first drive signal is a ramp signal whose voltage increases with a positive slope and decreases with a negative slope.

[0034] In a possible implementation manner, calculating the dynamic resistance value based on the first voltage and the first current measured by the detection module includes:

[0035] In the dynamic resistance value measurement phase, collecting a plurality of first currents and first voltages passing through the second resistor;

[0036] A first quotient of the first voltage and each of the first currents is calculated to obtain a plurality of dynamic resistance values.

[0037] In a possible implementation, the extracting the threshold voltage after determining the transfer characteristic curve of the GaN power device to be tested based on the first power supply voltage, the second voltage between the first terminal of the GaN power device to be tested and the second terminal of the GaN power device to be tested, and the third voltage between the control terminal of the GaN power device to be tested and the second terminal of the GaN power device to be tested, comprises:

[0038] In the threshold voltage measurement phase, multiple sets of second voltages and third voltages are obtained;

[0039] For each set of the second voltage and the third voltage, perform the following steps:

[0040] Calculating a first difference between the second voltage and the first power supply voltage; calculating a second quotient between the first difference and the first resistance value, and using the second quotient as a second current; establishing a corresponding relationship between the second current and the third voltage, and obtaining the transfer characteristic curve;

[0041] The threshold voltage is extracted from the transfer characteristic curve.

[0042] The beneficial effects of this application are as follows:

[0043] The present application provides a test device and method for a gallium nitride power device. The test device includes a power module, a measurement module, a detection module and a calculation module. The power module provides a first power supply voltage. On the one hand, after the measurement module turns on a first branch for measuring a dynamic resistance value under the control of a second drive signal, the gallium nitride power device to be tested is turned on under the control of the first drive signal. The dynamic resistance value is calculated based on a first voltage and a first current measured by the detection module. On the other hand, under the control of the second drive signal, a second branch for measuring a threshold voltage is turned on, and in the process of the first drive signal voltage increasing, the threshold voltage is determined based on the first power supply voltage, a second voltage between a first terminal and a second terminal of the gallium nitride power device to be tested, and a third voltage between a control terminal and a second terminal of the gallium nitride power device to be tested. Through the above device, the dynamic resistance and the threshold voltage of the gallium nitride power device can be determined simultaneously, thereby improving the accuracy of the test reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0045] Figure 1 A schematic diagram of the structure of a test device provided in an embodiment of the present application;

[0046] Figure 2 A circuit diagram of a measurement module provided in an embodiment of the present application;

[0047] Figure 3 A circuit diagram of a detection module provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of a voltage clamping circuit provided in an embodiment of the present application;

[0049] Figure 5 A circuit diagram of another testing device provided in an embodiment of the present application;

[0050] Figure 6 A flow chart of a testing method is provided for an embodiment of the present application;

[0051] Figure 7 A schematic diagram of another testing method provided in an embodiment of the present application;

[0052] Figure 8 A schematic diagram of voltage and current related to a test method provided in an embodiment of the present application;

[0053] Fig. 9 A schematic diagram of types of first driving signals provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0056] In the related art, a double pulse test (DPT) circuit is usually used to measure the dynamic resistance of GaN power devices. Its working principle is to apply a double pulse signal to the GaN device in a short period of time, measure the change in the dynamic resistance of the power device to be tested in the on state, and thus obtain the dynamic resistance parameters.

[0057] When conducting a comprehensive analysis of the reliability of GaN power devices, it is necessary not only to pay attention to the change in dynamic resistance, but also to consider the threshold voltage drift, because both are affected by the trap capture effect in the GaN material; however, the test equipment in the related art can only detect the dynamic resistance of GaN power devices, but cannot perform real-time measurement of the threshold voltage drift of the device under electrical stress (such as gate or drain bias), resulting in reduced accuracy in device reliability assessment.

[0058] In order to solve the above problems, the present application provides a test device for gallium nitride power devices, such as Figure 1, which is a schematic diagram of the structure of a test device provided in an embodiment of the present application, the test device is applied to GaN power devices, and the test device includes a power module 201, a measurement module 202, a detection module 203 and a calculation module (not shown in the figure);

[0059] The power module 201, the measuring module 202 and the detecting module 203 are connected in sequence to form a power loop;

[0060] The first end of the GaN power device S to be tested is electrically connected to the measurement module 202 and the detection module 203 respectively, the second end of the GaN power device S to be tested is electrically connected to the detection module 203 and grounded, and the control end of the GaN power device S to be tested is used to receive the first driving signal, and is turned on or off under the control of the first driving signal;

[0061] The power supply module 201 is used to provide a first power supply voltage V CC ;

[0062] The measuring module 202 is used to, under the control of the second driving signal, turn on the first branch for measuring the dynamic resistance value of the GaN power device S to be tested, and under the control of the second driving signal, turn off the first branch for measuring the threshold voltage V of the GaN power device S to be tested. th The second branch is turned on;

[0063] a calculation module, configured to calculate the dynamic resistance value R based on the first voltage and the first current measured by the detection module 203 when the first branch is turned on and the GaN power device S to be tested is turned on, and to calculate the dynamic resistance value R based on the first power supply voltage V when the second branch is turned on and the voltage of the first drive signal gradually increases; CC , a second voltage V between the first end of the GaN power device S to be tested and the second end of the GaN power device S to be tested DS , a third voltage V between the control terminal of the GaN power device S to be tested and the second terminal of the GaN power device S to be tested GS After determining the transfer characteristic curve of the GaN power device to be tested, the threshold voltage V th .

[0064] In an embodiment of the present application, a test device for a gallium nitride power device includes a power module, a measurement module, a detection module and a calculation module, wherein the power module, the measurement module and the detection module are connected in sequence to form a power circuit, and the power module is used to provide a first power supply voltage; on the one hand, under the control of a second drive signal, after the measurement module turns on a first branch for measuring a dynamic resistance value of a GaN power device to be tested, the GaN power device to be tested is turned on under the control of the first drive signal; the dynamic resistance value is calculated based on a first voltage and a first current measured by the detection module; on the other hand, under the control of the second drive signal, the first branch is disconnected, and a second branch for measuring a threshold voltage of the GaN power device to be tested is turned on, and in the process in which the voltage of the first drive signal gradually increases, the threshold voltage is determined based on the first power supply voltage, a second voltage between a first end of the GaN power device to be tested and a second end of the GaN power device to be tested, and a third voltage between a control end of the GaN power device to be tested and a second end of the GaN power device to be tested; the test device provided by the present application is suitable for simultaneously measuring the dynamic resistance and threshold voltage of the GaN power device when testing the GaN power device, thereby improving the accuracy of the reliability test.

[0065] In one embodiment, if Figure 2 , which is a circuit diagram of a measurement module provided in an embodiment of the present application, the measurement module 202 includes a first resistor R1, a first diode D1, a first inductor L1 and a switch tube S1;

[0066] The first end of the first resistor R1 is electrically connected to the cathode of the first diode D1, the first end of the first inductor L1 and the positive electrode of the power module 201, and the second end of the first resistor R1 is electrically connected to the second end of the switch tube S1, the first end of the GaN power device S to be tested and the detection module 203;

[0067] The anode of the first diode D1 is electrically connected to the second end of the first inductor L1 and the first end of the switch tube S1;

[0068] The control end of the switch tube S1 is used to receive the second driving signal.

[0069] In a specific implementation, the control end of the switch tube S1 is the gate G of the switch tube, the first end of the switch tube S1 is the drain D of the switch tube, and the second end of the switch tube S1 is the source S of the switch tube.

[0070] In the embodiment of the present application, the first inductor L1 included in the measuring module 202 may also include the first inductor L1 and a load resistor connected in series therewith, which is not limited in the embodiment of the present application.

[0071] In one embodiment, if Figure 3, which is a circuit diagram of a detection module provided in an embodiment of the present application, the detection module 203 includes a voltage clamping circuit 41 and a second resistor R2;

[0072] The first end of the voltage clamp circuit 41 is electrically connected to the second end of the switch tube S1, the second end of the first resistor R1, and the first end of the GaN power device to be tested, and the second end of the voltage clamp circuit 41 is electrically connected to the first end of the second resistor R2, the second end of the GaN power device to be tested S, and the ground end;

[0073] The second end of the second resistor R2 is electrically connected to the negative electrode of the power module 201 .

[0074] In the embodiments of the present application, Figure 4 As shown, the voltage clamping circuit 41 includes a second diode D2, a third diode D3, a fourth diode D4, a third resistor R3, a fourth resistor R4 and a second voltage source V2;

[0075] The cathode of the second diode D2 is electrically connected to the measurement module 202 and the first end of the GaN power device to be measured, and the anode of the second diode D2 is electrically connected to the cathode of the third diode D3, the cathode of the fourth diode D4, the first end of the third resistor R3, and the first end of the fourth resistor R4;

[0076] The second end of the third resistor R3 is electrically connected to the positive electrode of the second voltage source V2;

[0077] The cathode of the second voltage source V2 is electrically connected to the anode of the third diode D3, the anode of the fourth diode D4, the second end of the fourth resistor R4 and the first end of the second resistor R2;

[0078] The second end of the second resistor R2 is electrically connected to the negative electrode of the power module 201 .

[0079] In order to accurately extract the dynamic resistance of the GaN power device to be measured, the measuring equipment needs to have sufficient current measurement accuracy. Specifically, the current measurement accuracy needs to be greater than 1mA. In order to meet the requirements of bandwidth and measurement accuracy at the same time, the second resistor R2 uses a coaxial resistor. For example, the second resistor R2 can use a SSDN-414-10 coaxial resistor, which has the characteristics of high precision (accurate to four decimal places), high bandwidth and high measurement accuracy.

[0080] Secondly, the second diode D2 in the voltage clamping circuit 41 adopts a SiC diode, the third diode D3 adopts a Schottky diode, and the fourth diode D4 adopts a Zener diode, wherein the Zener diode is used to limit the measured voltage within its stable voltage to improve the measurement accuracy; the Schottky diode has a fast charging and discharging characteristic, so the voltage clamping circuit 41 can have a faster response speed, which is suitable for capturing the dynamic resistance changes of the GaN power device to be tested during high-speed switching.

[0081] It should be noted that the embodiment of the present application adopts a voltage clamping circuit. In specific implementation, different voltage clamping circuits can be selected according to actual needs, and the embodiment of the present application does not limit this.

[0082] In one embodiment, if Figure 5 , which is a circuit diagram of another test device provided in an embodiment of the present application, wherein the test device further includes an operational amplifier OP, and the power supply module 201 includes a capacitor C1 and a first voltage source V1;

[0083] The non-inverting input terminal of the operational amplifier OP is used to receive the first driving signal, and the inverting input terminal of the operational amplifier OP is electrically connected to the output terminal of the operational amplifier OP;

[0084] The operational amplifier OP is used to amplify the first drive signal to improve the load capacity of the first drive signal, obtain a third drive signal, and provide the third drive signal to the control terminal of the GaN power device S to be tested;

[0085] The capacitor C1 is connected in parallel with the first voltage source V1.

[0086] In the examples of this application, refer to Figure 5 The GaN power device to be tested is a switch tube S, the control end of the GaN power device to be tested is the gate of the switch tube S, the first end of the GaN power device to be tested is the drain of the switch tube S, and the second end of the GaN power device to be tested is the source of the switch tube S.

[0087] In addition, the test equipment provided by the present application can control the measurement interval time to increase flexibility.

[0088] Based on the same inventive concept, an embodiment of the present application also provides a testing method for gallium nitride power devices, which is applied to any of the above-mentioned testing devices. The principle of solving technical problems by the testing method is similar to the principle of solving technical problems by the testing device. The implementation of the testing method can refer to the implementation of the testing device, and the repeated parts will not be repeated.

[0089] like Figure 6As shown, a flow chart of a testing method is provided in an embodiment of the present application, which is applied to any of the testing devices described above, and the method includes:

[0090] S901: In a dynamic resistance value measurement stage, after the measurement module turns on the first branch for measuring the dynamic resistance value of the GaN power device to be measured under the control of the second driving signal, the GaN power device to be measured is turned on under the control of the first driving signal, and the detection module detects the first voltage and the first current; based on the first voltage and the first current, the dynamic resistance value is calculated;

[0091] S902: In the threshold voltage measurement stage, the voltage of the first drive signal gradually increases. Under the control of the second drive signal, the measurement module disconnects the first branch. After the second branch for measuring the threshold voltage of the power tube device to be tested is turned on, the GaN power device to be tested is turned on under the control of the first drive signal. After determining the transfer characteristic curve of the GaN power device to be tested based on the first power supply voltage, the second voltage between the first end of the GaN power device to be tested and the second end of the GaN power device to be tested, and the third voltage between the control end of the GaN power device to be tested and the second end of the GaN power device to be tested, the threshold voltage is extracted.

[0092] The embodiment of the present application provides a test method for gallium nitride power devices, which is applied to the above-mentioned test equipment; the method includes a dynamic resistance value measurement stage and a threshold voltage measurement stage. In the dynamic resistance value measurement stage, based on the control of the second drive signal, after the measurement module turns on the first branch for measuring the dynamic resistance value, based on the control of the first drive signal, the GaN power device to be tested is turned on, and the detection module detects the first voltage and the first current; based on the first voltage and the first current, the dynamic resistance value is calculated; in the threshold voltage measurement stage, the voltage of the first drive signal gradually increases, and under the control of the second drive signal, the first branch is disconnected, and after the second branch for measuring the threshold voltage of the GaN power device to be tested is turned on, under the control of the first drive signal, the GaN power device to be tested is turned on, and the threshold voltage is determined based on the first power supply voltage, the second voltage between the first end and the second end of the GaN power device to be tested, and the third voltage between the control end and the second end of the GaN power device to be tested; the method provided by the present application is suitable for simultaneously measuring the threshold voltage drift and dynamic resistance of the GaN device under circuit-level test stress bias, thereby improving the accuracy of reliability testing.

[0093] In one embodiment, before the dynamic resistance value measurement phase, the measurement method further includes a start-up phase and a freewheeling phase;

[0094] In the start-up phase, after the switch tube S1 in the measurement module 202 is turned on under the control of the second drive signal, the GaN power device to be measured is turned on under the control of the first drive signal;

[0095] In the freewheeling stage, under the control of the first driving signal, the GaN power device to be measured is disconnected, and the current passing through the first inductor L1 is freewheeled through the first diode D1 in the measuring module 202 .

[0096] In one embodiment, an electrical stress phase is further included before the start-up phase;

[0097] In the electrical stress stage, after the switch tube in the measurement module is disconnected under the control of the second drive signal, the GaN power device to be measured is disconnected under the control of the first drive signal.

[0098] In one embodiment, after the dynamic resistance value measurement stage and before the threshold voltage measurement stage, an interval stage is further included, and the method further includes:

[0099] In the interval stage, after the switch tube in the measurement module is turned off under the control of the second drive signal, the GaN power device to be measured is turned off under the control of the first drive signal.

[0100] For example, Figure 7 , which is a flow chart of another testing method provided in an embodiment of the present application;

[0101] S1001: In the electrical stress stage, after the switch tube S1 in the measurement module 202 is disconnected under the control of the second driving signal, the GaN power device to be measured is disconnected under the control of the first driving signal.

[0102] Specifically, refer to Figure 5 When the second driving signal is at a low level, the switch tube S1 in the measuring module 202 is disconnected (i.e., the first branch for measuring the dynamic resistance value of the GaN power device to be measured is disconnected), and the second branch is turned on; when the first driving signal is at a low level, the switch tube S is disconnected (i.e., the GaN power device to be measured is disconnected). At this time, the power module 201, the second branch (i.e., R1) and the detection module 203 form a loop, and the switch tube S2 is subjected to the power supply voltage V provided by the first voltage source V1. CC .

[0103] S1002: In the start-up phase, after the switch tube S1 in the measurement module 202 is turned on under the control of the second drive signal, the GaN power device to be measured is turned on under the control of the first drive signal.

[0104] Specifically, when the second drive signal is at a high level, the switch tube S1 in the measurement module 202 is turned on (that is, the first branch for measuring the dynamic resistance value of the GaN power device to be measured is turned on), and when the first drive signal is at a high level, the switch tube S2 is turned on (that is, the GaN power device to be measured is turned on). At this time, the power supply module 201, the first branch (that is, L1, D1, S1), the GaN power device to be measured and the detection module 203 form a loop, and the current passing through the first inductor L1 continues to increase.

[0105] It should be noted that, in actual operation, the switch tube S1 is turned on first, and after a delay time of several tens of ns, the switch tube S2 is turned on later.

[0106] S1003 : In the freewheeling stage, under the control of the first driving signal, the GaN power device to be tested is disconnected, and the current passing through the first inductor L1 is freewheeled through the first diode D1 in the measuring module 202 .

[0107] Specifically, the second drive signal is maintained at a high level, and the switch tube S1 is turned on; when the first drive signal becomes a low level, the switch tube S2 is disconnected (that is, the GaN power device to be tested is disconnected). At this time, the power module 201, the first branch (that is, L1, D1, S1) and the detection module 203 form a loop, and the current passing through the first inductor L1 is continued by the first diode D1, and the switch tube S2 bears the voltage stress of the first voltage source V1.

[0108] S1004: In the dynamic resistance value measurement stage, after the measurement module turns on the first branch for measuring the dynamic resistance value of the GaN power device to be measured under the control of the second drive signal, the GaN power device to be measured is turned on under the control of the first drive signal, and the detection module detects the first voltage and the first current; based on the first voltage and the first current, the dynamic resistance value is calculated.

[0109] Specifically, the second drive signal maintains a high level, and the switch tube S1 is turned on; the first drive signal becomes a high potential, the switch tube S2 is turned on, and continues to withstand the voltage stress of the first voltage source V1. At this time, the power module 201, the first branch (ie, L1, D1, S1), the GaN power device to be tested and the detection module 203 form a loop.

[0110] In the dynamic resistance value measurement phase, a plurality of first currents I passing through the second resistor are collected. shunt and the first voltage V DS_M ;

[0111] Calculate the first voltage V DS_M With each first current I shunt The first quotient value is obtained to obtain multiple dynamic resistance values ​​R. The specific formula is as follows:

[0112]

[0113] S1005: In the interval stage, after the switch tube in the measurement module is disconnected under the control of the second drive signal, the GaN power device to be measured is disconnected under the control of the first drive signal.

[0114] Specifically, when the second driving signal becomes a low level, the switch tube S1 in the measuring module 202 is disconnected (that is, the first branch for measuring the dynamic resistance value of the GaN power device to be measured is disconnected), and the second branch is turned on; when the first driving signal becomes a low level, the switch tube S2 is disconnected (that is, the GaN power device to be measured is disconnected). At this time, the power module 201, the second branch (that is, R1) and the detection module 203 form a loop, and the switch tube S2 is subjected to the power supply voltage V provided by the first voltage source V1. CC .

[0115] S1006: In the threshold voltage measurement stage, the voltage of the first drive signal gradually increases. Under the control of the second drive signal, the measurement module disconnects the first branch. After the second branch for measuring the threshold voltage of the power tube device to be tested is turned on, the GaN power device to be tested is turned on under the control of the first drive signal. After determining the transfer characteristic curve of the GaN power device to be tested based on the first power supply voltage, the second voltage between the first end of the GaN power device to be tested and the second end of the GaN power device to be tested, and the third voltage between the control end of the GaN power device to be tested and the second end of the GaN power device to be tested, the threshold voltage is extracted.

[0116] Specifically, the second drive signal maintains a low level, and the second branch is turned on; the first drive signal input voltage gradually increases, and the switch tube S2 is turned on (that is, the GaN power device to be tested is turned on). At this time, the power module 201, the second branch (that is, R1), the GaN power device to be tested and the detection module 203 form a loop.

[0117] Secondly, obtain multiple sets of second voltages V DS and the third voltage V GS ;

[0118] For each group of second voltage V DS and the third voltage V GS , calculate the second voltage V DS With the first power supply voltage V CC The first difference of

[0119] The second quotient of the first difference and the first resistance value R1 is calculated, and the second quotient is used as the second current I. The specific formula is as follows:

[0120]

[0121] Establish the second current I and the third voltage V GS(i.e., the first driving signal);

[0122] Based on the established corresponding relationship, the threshold voltage is determined. For example, based on the setting, when I is 1 mA, the corresponding third voltage V GS as the threshold voltage.

[0123] It should be noted that the first resistor R1 is a kilo-ohm resistor, and the test accuracy of the voltage clamp circuit 41 is two decimal places, so the second current I is 10 -5 ~10 -3 A level of current.

[0124] For example, Figure 8 FIG. 1 is a schematic diagram of voltage and current related to a test method provided in an embodiment of the present application, including a first drive signal, a second drive signal, a second voltage V DS and the current I between the first and second terminals of the GaN power device to be tested DS ;

[0125] Before time t0, it is the electrical stress stage;

[0126] The time period from t0 to t1 is the start-up phase;

[0127] The time period from t1 to t2 is the freewheeling stage;

[0128] The time period from t2 to t3 is the dynamic resistance value measurement stage;

[0129] The time period from t3 to t4 is the interval stage;

[0130] The time period from t4 to t5 is the threshold voltage measurement stage;

[0131] The time period from t5 to t6 is the ending part.

[0132] In the embodiment of the present application, the electrical stress stage, the start-up stage, the freewheeling stage and the dynamic resistance value measurement stage can be regarded as one stage, which is a complete dynamic resistance value measurement stage.

[0133] It should be noted that in the test method of the present application, the types of electrical stresses to which the GaN power device to be tested (i.e., the switch tube 2) is subjected include three types, namely, off-state voltage stress, hard switch stress, and soft switch stress;

[0134] In the off-state voltage stress stage, the first drive signal is at a low level and the second drive signal is at a low level, simulating that the GaN power device to be tested is subjected to all voltage stresses of the power module 201. For example, the electrical stress stage in the present application is the off-state voltage stress stage;

[0135] In the hard switch stress stage, the second driving signal is at a high level, the switch tube S1 in the measurement module 202 is turned on, and the current passing through the first inductor L1 increases, thereby simulating the hard switch stress of the GaN power device to be tested when it is turned on and off under high voltage and different currents. For example, the complete dynamic resistance value measurement stage in this application is the hard switch stress stage;

[0136] In the soft switching stress stage, when the first drive signal is at a high level and the second drive signal is at a high level, since the first resistor R1 is a large resistive load, the current flowing through the GaN power device to be tested is very small, which can be approximated as soft switching stress. For example, the threshold voltage measurement stage in the present application is a soft switching stress stage.

[0137] In one embodiment, during the threshold voltage measurement phase, as Fig. 9 , which is a schematic diagram of the types of the first driving signal of the present application;

[0138] The first type is a fast scan of the transfer characteristics, that is, the first drive signal A is a ramp signal whose voltage rises with a positive slope, which is suitable for the scenario where the characteristics of the GaN power device to be tested change rapidly;

[0139] The second is a slow scan of the transfer characteristics, that is, the first drive signal B is a step signal with a gradually increasing voltage, which has a higher test accuracy;

[0140] The third type is a double scan of the transfer characteristics, that is, the first drive signal C is a ramp signal in which the voltage rises with a positive slope and falls with a negative slope, forming a complete reciprocating scanning method, which can effectively detect the stability of the GaN power device to be tested.

[0141] The present application provides a test device and method for a gallium nitride power device. The test device includes a power module, a measurement module, a detection module and a calculation module. The power module provides a first power supply voltage. After the measurement module turns on a first branch for measuring a dynamic resistance value under the control of a second drive signal, the gallium nitride power device to be tested is turned on under the control of the first drive signal. The dynamic resistance value is calculated based on a first voltage and a first current measured by the detection module. On the other hand, under the control of the second drive signal, a second branch for measuring a threshold voltage is turned on, and in the process of increasing the voltage of the first drive signal, the threshold voltage is determined based on the first power supply voltage, a second voltage between a first terminal and a second terminal of the gallium nitride power device to be tested, and a third voltage between a control terminal and a second terminal of the gallium nitride power device to be tested. Through the above device, the changes in the dynamic resistance and the threshold voltage of the gallium nitride power device are determined at the same time, thereby improving the accuracy of the test reliability.

[0142] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0143] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0144] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0145] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0146] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A test device for gallium nitride power devices, characterized in that: The device includes a power module, a measuring module, a detection module and a calculation module; The power supply module, the measuring module and the detection module are connected in sequence to form a power circuit; The first end of the GaN power device to be tested is electrically connected to the measurement module and the detection module respectively, the second end of the GaN power device to be tested is electrically connected to the detection module and is grounded, and the control end of the GaN power device to be tested is used to receive a first driving signal, and is turned on or off under the control of the first driving signal; The power supply module is used to provide a first power supply voltage; The measuring module is used to, under the control of a second driving signal, turn on a first branch for measuring a dynamic resistance value of the GaN power device to be tested, and, under the control of the second driving signal, turn off the first branch and turn on a second branch for measuring a threshold voltage of the GaN power device to be tested; The calculation module is used to calculate the dynamic resistance value based on the first voltage and the first current measured by the detection module when the first branch is turned on and the GaN power device to be tested is turned on, and to extract the threshold voltage after determining the transfer characteristic curve of the GaN power device to be tested based on the first power supply voltage, the second voltage between the first end of the GaN power device to be tested and the second end of the GaN power device to be tested, and the third voltage between the control end of the GaN power device to be tested and the second end of the GaN power device to be tested when the second branch is turned on and the voltage of the first drive signal gradually increases.

2. The device according to claim 1, characterized in that The measuring module includes a first resistor, a first diode, a first inductor and a switch tube; The first end of the first resistor is electrically connected to the cathode of the first diode, the first end of the first inductor and the positive electrode of the power module, and the second end of the first resistor is electrically connected to the second end of the switch tube, the first end of the GaN power device to be tested and the detection module; An anode of the first diode is electrically connected to the second end of the first inductor and the first end of the switch tube; The control end of the switch tube is used to receive the second driving signal.

3. The device according to claim 1, characterized in that The detection module includes a voltage clamping circuit and a second resistor; The first end of the voltage clamping circuit is electrically connected to the second end of the switch tube, the second end of the first resistor, and the first end of the GaN power device to be tested, and the second end of the voltage clamping circuit is electrically connected to the first end of the second resistor, the second end of the GaN power device to be tested, and the ground end; The second end of the second resistor is electrically connected to the negative electrode of the power module.

4. The device according to claim 1, characterized in that The device also includes an operational amplifier; The non-inverting input terminal of the operational amplifier is used to receive the first driving signal, and the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the operational amplifier; The operational amplifier is used to amplify the first drive signal to obtain a third drive signal, and provide the third drive signal to the control terminal of the GaN power device to be tested.

5. The device according to any one of claims 1 to 4, characterized in that: The power supply module includes a capacitor and a first voltage source; The capacitor is connected in parallel with the first voltage source.

6. A test method for a gallium nitride power device, characterized in that: Applied to the test device according to any one of claims 1 to 5, the method comprises: In the dynamic resistance value measurement stage, after the measurement module turns on the first branch for measuring the dynamic resistance value of the GaN power device to be measured under the control of the second driving signal, the GaN power device to be measured is turned on under the control of the first driving signal, and the detection module detects the first voltage and the first current; the dynamic resistance value is calculated based on the first voltage and the first current; In the threshold voltage measurement stage, during the gradual increase of the voltage of the first drive signal, under the control of the second drive signal, the measurement module disconnects the first branch, and after the second branch for measuring the threshold voltage of the power tube device to be tested is turned on, under the control of the first drive signal, the GaN power device to be tested is turned on; based on the first power supply voltage, the second voltage between the first end of the GaN power device to be tested and the second end of the GaN power device to be tested, and the third voltage between the control end of the GaN power device to be tested and the second end of the GaN power device to be tested, the transfer characteristic curve of the GaN power device to be tested is determined, and then the threshold voltage is extracted.

7. The method according to claim 6, characterized in that Before the dynamic resistance value measurement phase, a start-up phase and a freewheeling phase are also included, and the method further includes: In the start-up phase, after the switch tube in the measurement module is turned on under the control of the second drive signal, the GaN power device to be measured is turned on under the control of the first drive signal; In the freewheeling stage, under the control of the first driving signal, the GaN power device to be measured is disconnected, and the flowing current of the first inductor is freewheeled through the first diode in the measuring module.

8. The method according to claim 7, characterized in that An electrical stress stage is included before the start-up stage, and the method further includes: In the electrical stress stage, after the switch tube in the measurement module is disconnected under the control of the second driving signal, the GaN power device to be measured is disconnected under the control of the first driving signal.

9. The method according to claim 6, characterized in that After the dynamic resistance value measurement stage and before the threshold voltage measurement stage, an interval stage is also included, and the method further includes: In the interval stage, after the switch tube in the measurement module is disconnected under the control of the second drive signal, the GaN power device to be measured is disconnected under the control of the first drive signal.

10. The method according to any one of claims 6 to 9, characterized in that: In the threshold voltage measurement stage, the first drive signal is a ramp signal whose voltage increases with a positive slope, or the first drive signal is a step signal whose voltage gradually increases, or the first drive signal is a ramp signal whose voltage increases with a positive slope and decreases with a negative slope.

11. The method according to any one of claims 6 to 9, characterized in that: The calculating the dynamic resistance value based on the first voltage and the first current measured by the detection module includes: In the dynamic resistance value measurement phase, collecting a plurality of first currents and first voltages passing through the second resistor; A first quotient of the first voltage and each of the first currents is calculated to obtain a plurality of dynamic resistance values.

12. The method according to any one of claims 6 to 9, characterized in that: The method extracting the threshold voltage after determining the transfer characteristic curve of the GaN power device to be tested based on the first power supply voltage, the second voltage between the first terminal of the GaN power device to be tested and the second terminal of the GaN power device to be tested, and the third voltage between the control terminal of the GaN power device to be tested and the second terminal of the GaN power device to be tested, comprises: In the threshold voltage measurement phase, multiple sets of second voltages and third voltages are obtained; For each set of the second voltage and the third voltage, perform the following steps: Calculating a first difference between the second voltage and the first power supply voltage; calculating a second quotient between the first difference and the first resistance value, and using the second quotient as a second current; establishing a corresponding relationship between the second current and the third voltage, and obtaining the transfer characteristic curve; The threshold voltage is extracted from the transfer characteristic curve.

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