Dynamic stress aging test method and system for GaN power devices

Abstract

The present application relates to a dynamic stress aging test method and system for GaN power devices, comprising: obtaining dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to periodically switch the on / off state of the GaN power device under test; obtaining test conditions based on the dynamic pulse voltage stress data and the temperature stress data; performing a dynamic stress aging test on the GaN power device under test according to the test conditions, and collecting electrical parameters of the GaN power device under test during the stress process; obtaining test results based on comparison of the electrical parameters with preset failure thresholds, and reflecting the reliability of the GaN power device in a more realistic and rigorous manner by applying a dynamic pulse voltage stress that is closer to the actual operating conditions of the GaN power device under test, while simultaneously rapidly monitoring the actual degradation of the electrical parameters online during the stress application process, thereby avoiding the problem of inaccurate measurement caused by offline testing and the rapid recovery characteristics of the device.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor device reliability testing, and in particular to a dynamic stress aging test method and system for GaN power devices. Background Art

[0002] With the advancement of integrated circuit and semiconductor technologies, third-generation semiconductor devices, represented by GaN (gallium nitride) materials, have become a key research direction in the next-generation strategic electronics industry due to their superior material properties, including a wide bandgap, high breakdown electric field, high electron mobility, and high thermal conductivity. Currently, the reliability assessment of GaN power devices generally uses the same test standards as traditional silicon (Si) devices. However, testing has shown that the effectiveness of these standards in evaluating the lifespan, failure mechanisms, and application of GaN power devices is unclear.

[0003] Currently, static electrical stress tests, such as high-temperature reverse bias and high-temperature gate bias tests, are used for aging tests of GaN power devices. During the process, the leakage current, junction temperature and other information of the device are recorded in real time, and offline testing of electrical parameters is performed only at the beginning, intermediate nodes and after the test. However, after the bias stress is removed, the electrical parameters will drift due to the rapid transfer of bound charge in the device, resulting in the acquired test data not reflecting the actual operating conditions. Therefore, it is not accurate to use this test data to determine whether the GaN power device has failed. Summary of the Invention

[0004] Based on this, it is necessary to provide a dynamic stress aging test method and system for GaN power devices to address the problem that traditional static electrical stress tests and offline electrical parameter tests cannot accurately judge the performance status of GaN power devices.

[0005] A dynamic stress aging test method for GaN power devices, the method comprising:

[0006] Acquiring dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to periodically switch the on / off state of the GaN power device under test;

[0007] Obtaining test conditions according to the dynamic pulse voltage stress data and the temperature stress data;

[0008] Performing a dynamic stress aging test on the GaN power device under test according to the test conditions, and collecting electrical parameters of the GaN power device under test during the stress process;

[0009] The test result is obtained by comparing the electrical parameter with a preset failure threshold.

[0010] In one embodiment, the test conditions include a stress application cycle, a parameter acquisition cycle, a test temperature, a conduction test voltage stress, and a blocking test voltage stress. The stress application cycle includes two or more preset time intervals, and the conduction test voltage stress and the blocking test voltage stress are alternately applied in each of the preset time intervals.

[0011] The test temperature, the conduction test voltage stress, the blocking test voltage stress and the preset time interval are set according to the temperature stress data and the dynamic pulse voltage stress data.

[0012] In one embodiment, the dynamic pulse voltage stress data includes gate dynamic pulse voltage stress data and drain dynamic pulse voltage stress data.

[0013] In one embodiment, the gate dynamic pulse voltage stress data includes a dynamic gate voltage level and a gate switching frequency, and the drain dynamic pulse voltage stress data includes a drain on-voltage stress, a dynamic drain voltage level and a drain switching frequency.

[0014] In one embodiment, the stress application cycle includes a gate stress application cycle and a drain stress application cycle, the conduction test voltage stress includes a gate conduction test voltage stress and a drain conduction test voltage stress, and the blocking test voltage stress includes a gate blocking test voltage stress and a drain blocking test voltage stress;

[0015] The gate stress application period is set according to the gate switching frequency, and the gate conduction test voltage stress and the gate blocking test voltage stress are set according to the dynamic gate voltage level;

[0016] The drain stress application period is set according to the drain switching frequency, the drain conduction test voltage stress is set according to the drain conduction voltage stress, and the drain blocking test voltage stress is set according to the dynamic leakage voltage level.

[0017] In one embodiment, the dynamic stress aging test includes a gate dynamic stress aging test and a drain dynamic stress aging test.

[0018] In one embodiment, performing a dynamic stress aging test on the GaN power device under test according to the test conditions and collecting electrical parameters of the GaN power device under test during the stress process includes:

[0019] Adjusting the temperature of the test box in which the GaN power device to be tested is placed to the test temperature;

[0020] Alternately applying the gate conduction test voltage stress and the gate blocking test voltage stress to the gate of the GaN power device under test according to a preset time interval of the gate stress application cycle;

[0021] The electrical parameters of the GaN power device under test during the stress process are collected according to the parameter collection cycle.

[0022] In one embodiment, performing a dynamic stress aging test on the GaN power device under test according to the test conditions and collecting electrical parameters of the GaN power device under test during the stress process includes:

[0023] Adjusting the temperature of the test box in which the GaN power device to be tested is placed to the test temperature;

[0024] Alternately applying the gate conduction test voltage stress, the drain conduction test voltage stress, the gate blocking test voltage stress, and the drain blocking test voltage stress to the gate and drain of the GaN power device under test according to a preset time interval of the drain stress application cycle;

[0025] The electrical parameters of the GaN power device under test during the stress process are collected according to the parameter collection cycle.

[0026] In one embodiment, the electrical parameters include threshold voltage, dynamic on-resistance, and leakage current.

[0027] In one embodiment, a GaN power device dynamic stress aging test system is provided, comprising a control module and a gate pulse voltage generation module, a drain pulse voltage generation module, a temperature adjustment module, and a parameter acquisition module connected to the control module, wherein the gate pulse voltage generation module, the drain pulse voltage generation module, and the parameter acquisition module are all connected to the GaN power device under test;

[0028] The control module is used to obtain dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to dynamically switch the on / off state of the GaN power device under test;

[0029] The control module is further configured to obtain test conditions based on the dynamic pulse voltage stress data and the temperature stress data;

[0030] The control module is also used to control the gate pulse voltage generation module, the drain pulse voltage generation module and the temperature adjustment module to perform a dynamic stress aging test on the GaN power device under test according to the test conditions, and control the parameter acquisition module to collect electrical parameters of the GaN power device under test during the stress process, and compare the electrical parameters with a preset failure threshold to obtain the test results.

[0031] The above-mentioned dynamic stress aging test method and system for GaN power devices uses dynamic pulse voltage stress data and temperature stress data to obtain test conditions, conducts dynamic stress aging tests on the GaN power device under test, periodically switches the on / off state of the GaN power device under test, and collects its electrical parameters during the stress application process. The test results are compared with the preset failure threshold based on the electrical parameters. By applying dynamic pulse voltage stress that is closer to the actual operating conditions of the GaN power device under test, the reliability of the GaN power device can be more realistically and rigorously reflected. At the same time, the degradation of the device's electrical parameters can be quickly monitored online during the stress application process, avoiding the problem of uncertainty caused by offline testing and the rapid recovery characteristics of the device, and more accurately understanding the actual degradation of the parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Flowchart of a dynamic stress aging test method for GaN power devices in one embodiment;

[0033] Figure 2 is a timing diagram of stress application and parameter collection in one embodiment;

[0034] Figure 3 1 is a timing diagram of applying gate dynamic pulse voltage stress during a gate stress application period in one embodiment;

[0035] Figure 4 1 is a timing diagram of drain dynamic pulse voltage stress application during a drain stress application period in one embodiment;

[0036] Figure 5 Schematic diagram of the process of gate dynamic stress aging test in one embodiment;

[0037] Figure 6 Schematic diagram of the process of a drain dynamic stress aging test in one embodiment;

[0038] Figure 7 1 is a system block diagram of a GaN power device dynamic stress aging test system in one embodiment;

[0039] Figure 8 Schematic diagram of the stress application location of a GaN power device in one embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0042] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0043] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0044] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0045] As described in the background technology section, static electrical stress tests, such as high-temperature reverse bias and high-temperature gate bias tests, are currently used for aging tests of GaN power devices. Generally, during the 1000-hour test, the leakage current, junction temperature and other information of the device are recorded in real time. The GaN power device is only removed from the test circuit at the beginning, intermediate nodes and after the test is completed, and the electrical parameters are tested offline separately. The existing static electrical stress test and offline test methods used for GaN power devices are not only unable to effectively monitor the real-time drift process of the device electrical parameters, but also when the static bias stress is removed, the electrical parameters such as dynamic on-resistance and threshold voltage drift with the rapid transfer of bound charge in the device. It is impossible to accurately obtain their true values ​​by removing the device and performing offline testing, and therefore it is impossible to determine whether the GaN power device has a "soft failure" phenomenon through this test data.

[0046] Based on this, this application proposes a dynamic stress aging test method for GaN power devices, which can more accurately evaluate the reliability of GaN power devices under actual working conditions, avoid problems such as inaccurate testing due to lax stress loading and offline test parameter drift, and achieve more accurate GaN power device aging life status assessment.

[0047] In one embodiment, a dynamic stress aging test method for a GaN power device is provided. Figure 1 As shown, the method includes steps 100 to 400, wherein:

[0048] Step 100: Acquire dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to periodically switch the on / off state of the GaN power device under test.

[0049] Among them, the dynamic pulse voltage stress data is used to generate a periodically changing pulse voltage stress, which is applied to the gate and drain of the GaN power device under test, and periodically switches the switching state of the GaN power device under test. According to the working principle of the GaN power device, its switching state includes the on state and the off state. Specifically, the dynamic pulse voltage stress can be a periodically changing forward voltage / reverse voltage. Taking the N-type channel GaN power device as an example, when the gate of the GaN power device under test is applied with a forward voltage, its switching state corresponds to the on state. When the gate of the GaN power device under test is switched to apply a reverse voltage, its switching state corresponds to the off state. The dynamic pulse voltage stress can also include a periodically changing forward small voltage / forward large voltage. When the gate of the GaN power device under test is applied with a forward voltage and the drain is applied with a forward small voltage, its switching state corresponds to a low-voltage on state. When the gate of the GaN power device under test is switched to apply a reverse voltage and the drain is switched to a forward large voltage, its switching state corresponds to a high-voltage blocking state.

[0050] Specifically, the content of the dynamic pulse voltage stress data used to generate dynamic pulse voltage stress is not unique and can be set according to the needs of the actual test. For example, the dynamic pulse voltage stress data may include a dynamic voltage level and a switching frequency. The dynamic voltage level is used to output different pulse voltage stress sizes within a preset voltage stress range to test the reliability of the GaN power device under different dynamic voltage stresses within the preset voltage stress range. It can be understood that the dynamic voltage level can be directly a list of voltage stress values ​​arbitrarily selected within the preset voltage stress range; it can also be an integer value, which is used to divide the preset voltage stress range using a fixed step size or a non-fixed step size according to the integer value to obtain different dynamic voltage stresses. The specific value of the dynamic voltage level can be set according to the actual test requirements of the GaN power device under test and is not limited. The preset voltage stress range is the voltage stress range that the GaN power device under test withstands during the switching process, including an upper voltage limit and a lower voltage limit. The specific value can be set according to the actual test requirements of the GaN power device under test. The switching frequency is used to determine the pulse voltage stress cycle to test the reliability of the GaN power device under test when periodically switching between on and off states at different frequencies. It can also be a list of test frequencies or an adjustable test frequency value. Therefore, during dynamic stress aging testing of GaN power devices, different dynamic pulse voltage stresses can be generated based on the dynamic voltage level and switching frequency parameters to perform aging tests on the GaN power device under test, achieving a test result that is closer to its actual operating conditions.

[0051] Furthermore, temperature stress data is used to set the ambient temperature during testing of the GaN power device under test. Specifically, by increasing the ambient temperature during testing, the life test of the GaN power device under test can be further accelerated. The content of temperature stress data is not unique and can correspond to one or more temperature values, which are used to set the ambient temperature during testing of the GaN power device under test.

[0052] In addition, there is no single way for the control device in the test system to obtain the dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test. The dynamic pulse voltage stress data and temperature stress data may be preset in the memory of the control device, and the data may be obtained according to one or more conditions such as the specific model of the GaN power device under test, the device type, or the rated parameters in actual operation. For example, the device type may be that the GaN power device under test is an N-type channel GaN power device or a P-type channel GaN power device, and the rated parameters may be the maximum gate voltage / maximum drain voltage that the GaN power device under test can withstand. Alternatively, the control device may be configured with a display module, and the tester may obtain the data by inputting the dynamic pulse voltage stress data and temperature stress data required for the GaN power device under test.

[0053] Step 200: Obtaining test conditions according to dynamic pulse voltage stress data and temperature stress data.

[0054] Specifically, after obtaining the dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test, the test conditions can be set accordingly to perform a dynamic stress aging test on the GaN power device under test. In one embodiment, the test conditions include a stress application cycle, a parameter acquisition cycle, a test temperature, a conduction test voltage stress, and a blocking test voltage stress. The stress application cycle includes two or more preset time intervals, and the conduction test voltage stress and the blocking test voltage stress are alternately applied in each preset time interval. The test temperature, conduction test voltage stress, blocking test voltage stress, and the preset time intervals are set based on the temperature stress data and the dynamic pulse voltage stress data.

[0055] It can be understood that the stress application cycle is the time for applying dynamic pulse voltage stress to the GaN power device under test. The specific duration is not unique and can be set according to the test requirements. It can be a few minutes or a few hours. A stress application cycle includes more than two preset time intervals. Each preset time interval alternately applies the conduction test voltage stress and the blocking test voltage stress, so that the GaN power device under test is alternately in the on state and the off state within each preset time interval. The length of the preset time interval is determined according to the switching frequency in the dynamic pulse voltage stress data. The parameter acquisition cycle is the time for collecting the electrical parameters of the GaN power device under test during the stress process through the parameter acquisition module. The specific duration is not unique. However, due to the fast recovery characteristics of GaN power devices, the parameter acquisition cycle is generally set to within 10 microseconds to ensure that the electrical parameters of the GaN power device under test during the stress process are captured in a timely manner.

[0056] Furthermore, if Figure 2 As shown, after each stress application cycle, a parameter acquisition cycle is entered, and then the stress application cycle is entered again. It can be understood that the combination of a stress application cycle and a parameter acquisition cycle is the time to complete a dynamic stress aging test. Correspondingly, in other embodiments, the test conditions may also include the number of cycles. Among them, the number of cycles is the number of times the combination of the stress application cycle and the parameter acquisition cycle is cyclically executed. Its value is not unique and can be determined according to the actual test scheme design. During the cycle process, the test temperature, conduction test voltage stress, blocking test voltage stress and preset time interval in each stress application cycle can be the same or different.

[0057] Step 300: Perform a dynamic stress aging test on the GaN power device under test according to test conditions, and collect electrical parameters of the GaN power device under test during the stress process.

[0058] Specifically, since the dynamic stress aging test of the GaN power device under test may be to apply dynamic pulse voltage stress to the gate or drain of the GaN power device under test, and the service life and performance of the GaN power device under test may be affected in different aspects when the dynamic pulse voltage stress is applied to the gate or drain, it is necessary to perform two tests under different conditions according to different test requirements. Therefore, in one embodiment, the dynamic stress aging test includes a gate dynamic stress aging test and a drain dynamic stress aging test. It can be understood that the gate dynamic stress aging test is to apply different dynamic pulse voltage stresses to the gate of the GaN power device under test according to the test conditions, so that the GaN power device under test is periodically switched between the on state and the off state. The drain dynamic stress aging test is to apply different dynamic pulse voltage stresses to the drain of the GaN power device under test according to the test conditions, so that the GaN power device under test is periodically switched between the low-voltage on state and the high-voltage blocking state.

[0059] Furthermore, the electrical parameters of the GaN power device under test during the stress process are key parameters for evaluating its reliability and lifespan. The types of electrical parameters are not unique and can be selected based on the basic parameters of the GaN power device under test. For example, they can be threshold voltage, dynamic on-resistance, gate leakage current, drain saturation current, and drain-source resistance. In the embodiments of the present application, the electrical parameters include threshold voltage, dynamic on-resistance, and leakage current.

[0060] Among them, when collecting the threshold voltage, dynamic on-resistance and leakage current of the GaN power device under test during the parameter acquisition cycle, there is no need to remove the GaN power device under test from the stress-applying test board, and the GaN power device under test can be directly connected for collection. Specifically, the method of collecting the threshold voltage, dynamic on-resistance and leakage current is not unique, and can be set according to actual needs. For example, the threshold voltage can be obtained by utilizing the self-commutating reverse conduction characteristics of the GaN power device under test, presetting the linear relationship between its threshold voltage and the reverse conduction voltage drop, and then collecting the corresponding linear relationship between the reverse conduction voltage drop between the drain and the source. The dynamic on-resistance can be obtained by applying a pulse current to the GaN power device under test, and then collecting the voltage between the drain and the source, and then calculating it through the volt-ampere characteristic. The leakage current can be directly collected using a current sensor or a current acquisition circuit.

[0061] Furthermore, electrical parameters can be collected once or multiple times within a parameter acquisition cycle. After multiple acquisitions, a graph of the degradation of electrical parameters over time can be plotted to monitor the actual degradation of the sensitive parameters of the GaN power device under test. Furthermore, by generating different dynamic pulse voltage stresses based on the dynamic voltage level and switching frequency to perform aging tests on the GaN power device under test, the different failure mechanisms of the sensitive parameters of the device under test can be monitored under different dynamic pulse voltage stress conditions.

[0062] Step 400: Compare the electrical parameters with a preset failure threshold to obtain a test result.

[0063] Specifically, when evaluating the reliability of the GaN power device under test, the electrical parameters of the GaN power device under test are collected and recorded in real time after the stress application cycle, and then the collected electrical parameter values ​​are compared with the preset failure threshold. If the preset failure threshold is met, it means that the GaN power device under test has failed during the stress application process, and a test result of device failure is obtained; if after the entire test process is completed, all the collected electrical parameter values ​​do not meet the preset failure threshold, it means that the GaN power device under test has not failed during the stress application process, and a test result of high device reliability is obtained. In other embodiments, in the test for evaluating the life of the GaN power device under test, the test can continue to stress the GaN power device under test, and then collect and record the electrical parameters of the GaN power device under test in real time after the stress application cycle until the collected electrical parameters meet the preset failure threshold, and the life at this time can be recorded as the test result.

[0064] The test results of the entire dynamic stress aging test process can be saved in the storage module for subsequent drawing of degradation curves, analysis of parameter drift characteristics, etc., to further evaluate the reliability and life of GaN power devices. At the same time, the test results can also be displayed through the display module.

[0065] The above-mentioned dynamic stress aging test method for GaN power devices uses dynamic pulse voltage stress data to obtain test conditions and conduct dynamic stress aging tests on the GaN power device under test. The on-off state of the GaN power device under test is periodically switched, and its electrical parameters during the stress application process are collected. The test results are compared with the preset failure threshold based on the electrical parameters. By applying dynamic pulse voltage stress that is closer to the actual operating conditions of the GaN power device under test, the reliability and lifespan of the GaN power device can be more realistically and rigorously reflected. At the same time, the degradation of the device's electrical parameters can be quickly monitored online during the stress application process, avoiding the problem of uncertainty caused by offline testing and the rapid recovery characteristics of the device, and more accurately understanding the actual degradation of the parameters.

[0066] In one embodiment, the dynamic pulse voltage stress data includes gate dynamic pulse voltage stress data and drain dynamic pulse voltage stress data. The gate dynamic pulse voltage stress data is used to generate a periodically varying pulse voltage stress applied to the gate of the GaN power device under test, so as to cause the GaN power device under test to periodically switch between on and off states. The drain dynamic pulse voltage stress data is used to generate a periodically varying pulse voltage stress applied to the drain of the GaN power device under test, so as to cause the GaN power device under test to periodically switch to a high-voltage blocking state.

[0067] In one embodiment, the gate dynamic pulse voltage stress data includes a dynamic gate voltage level and a gate switching frequency. GS Used to output forward / reverse gate pulse voltage stress V with different amplitudes within the preset gate voltage stress range GS , applied to the gate of the GaN power device under test to dynamically switch its on / off state, and test the reliability of the GaN power device under test under different dynamic voltage stress within the gate voltage stress range. For example, assuming the preset gate voltage stress range is ±30V and the dynamic gate voltage level is N GS When set to three levels and evenly divided by a fixed step size, the gate of the GaN power device under test can be subjected to three levels of dynamic pulse voltage stress tests, namely -10V~10V, -20V~20V, and -30V~30V. Corresponding to the switching frequency, the gate switching frequency F GS Used to determine the gate pulse voltage stress V GS The frequency of the test cycle is used to test the reliability of the GaN power device under test when periodically switching between on and off states at different frequencies. The specific value can be set according to the actual test requirements. For example, the test can be carried out within the range of 10Hz to 1MHz.

[0068] Similarly, in one embodiment, the drain dynamic pulse voltage stress data includes drain on-state voltage stress, dynamic drain voltage level, and drain switching frequency. The drain on-state voltage stress is the drain pulse voltage stress V applied to the drain of the GaN power device under test to put the GaN power device under test in a low-voltage on-state. DS , can be set to the voltage drop between the drain and source under normal working conditions according to the parameters of the GaN power device being tested, which is generally a small forward voltage. Dynamic leakage voltage level N DS With dynamic gate voltage level N GS The corresponding values ​​are consistent and are used to output forward drain pulse voltage stress V with different amplitudes within the preset drain voltage stress range. DS, the gate of the GaN power device under test is dynamically switched to a high voltage blocking state, and the reliability of the GaN power device under test is tested under different dynamic voltage stresses within its rated maximum voltage range. For example, assuming the preset drain voltage stress range is 0-2000V and the dynamic leakage voltage level is N DS When the three-level division is set, the drain of the GaN power device under test can be subjected to three levels of dynamic pulse voltage stress tests, namely 500V, 1000V and 2000V. GS Correspondingly, the drain switching frequency F DS Used to determine the drain pulse voltage stress V DS The specific value can be determined by the gate switching frequency F GS The test can also be carried out in the range of 10Hz to 1MHz according to actual test requirements.

[0069] In one embodiment, the stress application cycle includes a gate stress application cycle and a drain stress application cycle, the on-state test voltage stress includes a gate on-state test voltage stress and a drain on-state test voltage stress, and the blocking test voltage stress includes a gate blocking test voltage stress and a drain blocking test voltage stress; the gate stress application cycle is set according to the gate switching frequency, and the gate on-state test voltage stress and the gate blocking test voltage stress are set according to the dynamic gate voltage level; the drain stress application cycle is set according to the drain switching frequency, the drain on-state test voltage stress is set according to the drain on-state voltage stress, and the drain blocking test voltage stress is set according to the dynamic drain voltage level.

[0070] Specifically, according to the dynamic stress aging test of the GaN power device under test, dynamic pulse voltage stress can be applied to the gate or drain of the GaN power device under test respectively, and the stress application cycle can be divided into a gate stress application cycle and a drain stress application cycle. It can be understood that the gate dynamic stress aging test is performed during the gate stress application cycle, and the drain dynamic stress aging test is performed during the drain stress application cycle. Among them, the gate stress application cycle and the drain stress application cycle also include more than two preset time intervals. Correspondingly, in each preset time interval of the gate stress application cycle, the gate conduction test voltage stress and the gate blocking test voltage stress are applied alternately, so that the GaN power device under test is cyclically switched between the on state and the off state. In each preset time interval of the drain stress application cycle, the gate conduction test voltage stress and the drain conduction test voltage stress, the gate blocking test voltage stress and the drain blocking test voltage stress are applied alternately, so that the GaN power device under test is cyclically switched between the low-voltage on state and the high-voltage blocking state.

[0071] Furthermore, the number of cycles may also include gate cycles and drain cycles. The gate cycle number is the number of times the gate stress application period and the parameter collection period are cyclically executed, while the drain cycle number is the number of times the drain stress application period and the parameter collection period are cyclically executed. The specific values ​​of the gate cycle number and the drain cycle number are not unique and can be set according to actual test requirements. They can be set to the same or different, and there is no limitation.

[0072] Furthermore, if Figure 3 As shown, the gate stress application period is based on the gate switching frequency F GS Specifically, we can first set the gate switching frequency F GS Get the gate switching period T GS , and then set the gate stress application period to the gate switching period T GS The preset integer multiples can be set according to the test requirements. Then, the gate switching period T GS It is divided into a first preset time interval and a second preset time interval. During the first preset time interval, a gate conduction test voltage stress is applied to the gate of the GaN power device under test. During the second preset time interval, a gate blocking test voltage stress is applied to the gate of the GaN power device under test. The gate conduction test voltage stress and the gate blocking test voltage stress are determined according to the dynamic gate voltage level N. GS Settings such as Figure 3 The gate conduction test voltage stress is based on the dynamic gate voltage level N GS Output positive gate pulse voltage stress V GS To make the GaN power device under test in the on state; the gate blocking test voltage stress is based on the dynamic gate voltage level N GS Output reverse gate pulse voltage stress V GS , so that the GaN power device under test is in the off state.

[0073] Likewise, if Figure 4 As shown, the drain stress application period is based on the drain switching frequency F DS Setting. According to the drain switching frequency F DS Get the drain switching period T DS , and then set the drain stress application period to the drain switching period T DS The preset integer multiples can be set according to the test requirements and can be consistent with the preset integer multiples of the gate stress application period. Then, the drain switching period T DSIt is divided into a third preset time interval and a fourth preset time interval. In the third preset time interval, a gate conduction test voltage stress is applied to the gate of the GaN power device under test, and a drain conduction voltage stress is applied to the drain of the GaN power device under test. In the fourth preset time interval, a gate blocking test voltage stress is applied to the gate of the GaN power device under test, and a drain blocking test voltage stress is applied to the drain of the GaN power device under test. Figure 4 As shown in the figure, the drain conduction test voltage stress can be directly fixed to the drain conduction voltage stress, which is generally set to a smaller forward voltage. The drain blocking test voltage stress is based on the dynamic leakage voltage level N D Output forward drain pulse voltage stress V DS , so that the GaN power device under test is in a high-voltage blocking state.

[0074] In one embodiment, Figure 5 As shown, when performing the gate dynamic stress aging test, step 300 includes steps 301 to 303, wherein:

[0075] Step 301: Adjust the temperature of the test box containing the GaN power device to be tested to the test temperature.

[0076] Specifically, during the test, the GaN power device to be tested needs to be placed in a test chamber, and the temperature of the test chamber is adjusted to the test temperature, wherein the test temperature is determined based on the temperature stress data obtained in step 100 .

[0077] Step 302: alternately applying a gate-on test voltage stress and a gate-blocking test voltage stress to the gate of the GaN power device under test according to a preset time interval of a gate stress application cycle.

[0078] Specifically, the gate pulse voltage generating module is connected to the gate of the GaN power device under test, as shown in the following example. Figure 3 In the method shown, gate conduction test voltage stress and gate blocking test voltage stress are alternately outputted during a preset time interval of a gate stress application cycle and applied to the gate of the GaN power device under test, periodically switching the GaN power device under test between the on state and the off state.

[0079] Step 303: Collect electrical parameters of the GaN power device under test during the stress process according to a parameter collection cycle.

[0080] Specifically, after the gate stress application period ends, that is, during the parameter acquisition period, the electrical parameters of the GaN power device under test are collected in real time. In this embodiment, by continuously acquiring the electrical parameters of the GaN power device under test during the parameter acquisition period, parameter degradation can be monitored. By comparing these parameters with a preset failure threshold, it can also be determined whether the GaN power device under test has failed.

[0081] Furthermore, after completing one gate stress application cycle and parameter collection cycle, the stress application and parameter collection cycle can be continued for another gate stress application cycle and parameter collection cycle according to the test temperature, gate conduction test voltage stress, and gate blocking test voltage stress under the same conditions, returning to step 302 until the gate cycle number is reached. In addition, after the cycle reaches the gate cycle number, the gate dynamic stress aging test of the GaN power device under test can be performed according to the test temperature, gate conduction test voltage stress, and gate blocking test voltage stress under the next conditions, or the drain dynamic stress aging test can be performed, or the entire test can be terminated. There is no limitation and the test is carried out according to the test plan settings.

[0082] In one embodiment, Figure 6 As shown, when performing the drain dynamic stress aging test, step 300 includes steps 305 to 307, wherein:

[0083] Step 305: Adjust the temperature of the test box containing the GaN power device to the test temperature. The temperature adjustment steps are the same as those in the gate dynamic stress aging test and will not be described here in detail.

[0084] Step 306: alternately applying the gate conduction test voltage stress, the drain conduction test voltage stress, the gate blocking test voltage stress, and the drain blocking test voltage stress to the gate and drain of the GaN power device under test according to a preset time interval of the drain stress application cycle.

[0085] Specifically, the gate pulse voltage generating module is connected to the gate of the GaN power device under test, and the drain pulse voltage generating module is connected to the drain of the GaN power device under test. Figure 3 In the manner shown, during the preset time interval of the gate stress application cycle, the gate conduction test voltage stress and the gate blocking test voltage stress under the fixed normal state are alternately output and applied to the gate of the GaN power device under test, and the GaN power device under test is periodically switched between the conduction state and the off state. Figure 4 In the manner shown, the drain conduction test voltage stress and the drain blocking test voltage stress, which are alternately output during a preset time interval of the drain stress application cycle, are applied to the drain of the GaN power device under test, periodically switching the GaN power device under test between a low-voltage conduction state and a high-voltage blocking state.

[0086] Step 307: Collect electrical parameters of the GaN power device under test during the stress process according to the parameter collection cycle. The steps for collecting electrical parameters are the same as those in the gate dynamic stress aging test and will not be repeated here.

[0087] Similarly, after completing a drain stress application cycle and parameter collection cycle, the stress application and parameter collection of a drain stress application cycle and parameter collection cycle can be continued according to the test temperature, gate conduction test voltage stress, drain conduction test voltage stress, gate blocking test voltage stress, and drain blocking test voltage stress under the same conditions, returning to step 306 until the drain cycle number is reached. In addition, after the cycle reaches the drain cycle number, the GaN power device under test can be subjected to a drain dynamic stress aging test according to the next test temperature, gate conduction test voltage stress, drain conduction test voltage stress, gate blocking test voltage stress, and drain blocking test voltage stress, or it can be subjected to a gate dynamic stress aging test, or the entire test can be terminated. There is no limitation and the test is carried out according to the test plan settings.

[0088] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0089] In one embodiment, Figure 7As shown, a GaN power device dynamic stress aging test system is provided, including a control module 710 and a gate pulse voltage generation module 720, a drain pulse voltage generation module 730, a temperature adjustment module 740 and a parameter acquisition module 750 connected to the control module 710, the gate pulse voltage generation module 720, the drain pulse voltage generation module 730 and the parameter acquisition module 740 are all connected to the GaN power device under test; the control module 710 is used to obtain dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to dynamically switch the switching state of the GaN power device under test; the control module 710 is also used to obtain test conditions based on the dynamic pulse voltage stress data and the temperature stress data; the control module 710 is also used to control the gate pulse voltage generation module 720, the drain pulse voltage generation module 730 and the temperature adjustment module 740 according to the test conditions to perform a dynamic stress aging test on the GaN power device under test, and control the parameter acquisition module 750 to collect electrical parameters of the GaN power device under test during the stress process, and compare the electrical parameters with a preset failure threshold to obtain a test result.

[0090] Specifically, the GaN power device to be tested is first placed in a temperature-adjustable test environment. This temperature-adjustable test environment can be a temperature-adjustable environmental test chamber or a system such as a constant-temperature oil pool. In practical applications, the test environment temperature should be adjustable between room temperature and 200°C. Different test temperatures are set, and dynamic stress aging tests are performed at different test temperatures to achieve the purpose of accelerating device life testing. Parameter acquisition module 750 is used to collect the electrical parameters of the GaN power device under test in real time after the stress application cycle ends, that is, during the parameter acquisition cycle.

[0091] Furthermore, if Figure 8 As shown, the gate pulse voltage generation module 720 and the drain pulse voltage generation module 730 are respectively connected to the gate G and drain D of the GaN power device under test. The gate pulse voltage generation module 720 is used to alternately output gate conduction test voltage stress and gate blocking test voltage stress during the preset time interval of the gate stress application cycle according to the control instructions of the control module 710, apply them to the gate of the GaN power device under test, and periodically switch the GaN power device under test between the on state and the off state. The drain pulse voltage generation module 730 is used to alternately output drain conduction test voltage stress and drain blocking test voltage stress during the preset time interval of the drain stress application cycle according to the control instructions of the control module 710, apply them to the drain of the GaN power device under test, and periodically switch the GaN power device under test between the low voltage conduction state and the high voltage blocking state.

[0092] In addition, the GaN power device dynamic stress aging test system may further include a storage module and a display module connected to the control module 710, for storing and displaying data and test results of the dynamic stress aging test of the tested GaN power device.

[0093] For the specific limitations of the dynamic stress aging test system for GaN power devices, please refer to the limitations of the dynamic stress aging test method for GaN power devices mentioned above, which will not be repeated here.

[0094] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A dynamic stress aging test method for GaN power devices, characterized in that: The method includes: Acquiring dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to periodically switch the on / off state of the GaN power device under test; The test conditions are obtained according to the dynamic pulse voltage stress data and the temperature stress data; wherein the test conditions include a stress application period, a parameter acquisition period, a test temperature, a conduction test voltage stress, and a blocking test voltage stress; the dynamic pulse voltage stress data include gate dynamic pulse voltage stress data and drain dynamic pulse voltage stress data; the gate dynamic pulse voltage stress data is used to generate a periodically varying pulse voltage stress applied to the gate of the GaN power device under test, so that the GaN power device under test periodically switches the switching state; the drain dynamic pulse voltage stress data is used to generate a periodically varying pulse voltage stress applied to the drain of the GaN power device under test, so that the GaN power device under test periodically switches to a high-voltage blocking state; Performing a dynamic stress aging test on the GaN power device under test according to the test conditions, and collecting electrical parameters of the GaN power device under test during the stress process; The test result is obtained by comparing the electrical parameter with a preset failure threshold.

2. The dynamic stress aging test method for GaN power devices according to claim 1, characterized in that: The stress application cycle includes more than two preset time intervals, and the conduction test voltage stress and the blocking test voltage stress are applied alternately in each of the preset time intervals; The test temperature, the conduction test voltage stress, the blocking test voltage stress and the preset time interval are set according to the temperature stress data and the dynamic pulse voltage stress data.

3. The dynamic stress aging test method for GaN power devices according to claim 2, characterized in that: The gate dynamic pulse voltage stress data includes a dynamic gate voltage level and a gate switching frequency, and the drain dynamic pulse voltage stress data includes a drain on-voltage stress, a dynamic drain voltage level and a drain switching frequency.

4. The dynamic stress aging test method for GaN power devices according to claim 3, characterized in that: The stress application cycle includes a gate stress application cycle and a drain stress application cycle, the conduction test voltage stress includes a gate conduction test voltage stress and a drain conduction test voltage stress, and the blocking test voltage stress includes a gate blocking test voltage stress and a drain blocking test voltage stress; The gate stress application period is set according to the gate switching frequency, and the gate conduction test voltage stress and the gate blocking test voltage stress are set according to the dynamic gate voltage level; The drain stress application period is set according to the drain switching frequency, the drain conduction test voltage stress is set according to the drain conduction voltage stress, and the drain blocking test voltage stress is set according to the dynamic leakage voltage level.

5. The dynamic stress aging test method for GaN power devices according to claim 4, characterized in that: The dynamic stress aging test includes a gate dynamic stress aging test and a drain dynamic stress aging test.

6. The dynamic stress aging test method for GaN power devices according to claim 5, characterized in that: The step of performing a dynamic stress aging test on the GaN power device under test according to the test conditions and collecting electrical parameters of the GaN power device under test during the stress process includes: Adjusting the temperature of the test box in which the GaN power device to be tested is placed to the test temperature; Alternately applying the gate conduction test voltage stress and the gate blocking test voltage stress to the gate of the GaN power device under test according to a preset time interval of the gate stress application cycle; The electrical parameters of the GaN power device under test during the stress process are collected according to the parameter collection cycle.

7. The dynamic stress aging test method for GaN power devices according to claim 5, characterized in that: The step of performing a dynamic stress aging test on the GaN power device under test according to the test conditions and collecting electrical parameters of the GaN power device under test during the stress process includes: Adjusting the temperature of the test box in which the GaN power device to be tested is placed to the test temperature; Alternately applying the gate conduction test voltage stress, the drain conduction test voltage stress, the gate blocking test voltage stress, and the drain blocking test voltage stress to the gate and drain of the GaN power device under test according to a preset time interval of the drain stress application cycle; The electrical parameters of the GaN power device under test during the stress process are collected according to the parameter collection cycle.

8. The dynamic stress aging test method for GaN power devices according to any one of claims 1 to 7, characterized in that: The electrical parameters include threshold voltage, dynamic on-resistance and leakage current.

9. A GaN power device dynamic stress aging test system, characterized in that: It includes a control module and a gate pulse voltage generating module, a drain pulse voltage generating module, a temperature regulating module and a parameter acquisition module connected to the control module, wherein the gate pulse voltage generating module, the drain pulse voltage generating module and the parameter acquisition module are all connected to the GaN power device under test; The control module is used to obtain dynamic pulse voltage stress data and temperature stress data corresponding to the GaN power device under test; wherein the dynamic pulse voltage stress data is used to dynamically switch the on / off state of the GaN power device under test; The control module is further configured to obtain test conditions based on the dynamic pulse voltage stress data and the temperature stress data; wherein the test conditions include a stress application period, a parameter acquisition period, a test temperature, a conduction test voltage stress, and a blocking test voltage stress; the dynamic pulse voltage stress data includes gate dynamic pulse voltage stress data and drain dynamic pulse voltage stress data; the gate dynamic pulse voltage stress data is configured to generate a periodically varying pulse voltage stress applied to the gate of the GaN power device under test, so that the GaN power device under test periodically switches between switching states; and the drain dynamic pulse voltage stress data is configured to generate a periodically varying pulse voltage stress applied to the drain of the GaN power device under test, so that the GaN power device under test periodically switches to a high-voltage blocking state. The control module is also used to control the gate pulse voltage generation module, the drain pulse voltage generation module and the temperature adjustment module to perform a dynamic stress aging test on the GaN power device under test according to the test conditions, and control the parameter acquisition module to collect electrical parameters of the GaN power device under test during the stress process, and compare the electrical parameters with a preset failure threshold to obtain a test result.

10. The GaN power device dynamic stress aging test system according to claim 9, characterized in that: The gate pulse voltage generating module and the drain pulse voltage generating module are respectively connected to the gate and drain of the GaN power device under test; The gate pulse voltage generating module is used to alternately output gate conduction test voltage stress and gate blocking test voltage stress during a preset time interval of a gate stress application cycle according to a control instruction of the control module, and apply the stress to the gate of the GaN power device under test, thereby periodically switching the GaN power device under test between an on state and an off state; The drain pulse voltage generating module is used to alternately output drain conduction test voltage stress and drain blocking test voltage stress in a preset time interval of the drain stress application cycle according to the control instruction of the control module, apply them to the drain of the GaN power device under test, and periodically switch the GaN power device under test between a low-voltage conduction state and a high-voltage blocking state.

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