Method, apparatus and medium for measuring trap parameters of gallium nitride devices

Abstract

This application is applicable to the field of transistor technology, and provides a method, device and medium for measuring defect parameters of a gallium nitride device. The method for measuring defect parameters includes: applying a first voltage with a first duration between the gate and the source in the first stage of each first measurement period; applying a second voltage with a second duration between the drain and the source in the second stage; determining a fourth drain current of each first measurement period at the end of each second stage; determining a target duration based on N first durations and the fourth drain current; determining a target voltage based on M first voltages and the fourth drain current; in the second measurement period, applying the target voltage with the target duration between the gate and the source, and applying a third voltage between the drain and the source, measuring the value of a preset performance parameter, and determining the value of a preset defect parameter, so that the value of the preset defect number can be measured after fixing the charging state of the trap, improving the accuracy of measuring the defect parameters of the gallium nitride device.

Description

Technical Field

[0001] This application belongs to the technical field of transistors, and particularly relates to a method, device, and medium for measuring defect parameters of a gallium nitride device. Background Art

[0002] Gallium nitride (GaN) devices not only have excellent characteristics such as a large bandgap width of GaN material, a high critical breakdown electric field, a high electron saturation drift velocity, high temperature resistance, radiation resistance, and good chemical stability, but also GaN material can form a two-dimensional electron gas (2DEG) channel with high concentration and high mobility with materials such as aluminum gallium nitride (AlGaN). Therefore, gallium nitride devices are suitable for applications in high-voltage, high-power, and high-temperature scenarios.

[0003] However, currently, gallium nitride devices still face challenges in terms of reliability. For example, there are many electron or hole traps in the source, gate, and drain of gallium nitride devices and the materials on both sides of the two-dimensional electron gas, and these traps will cause changes in the performance parameters of gallium nitride devices. In order to evaluate the impact of traps on gallium nitride devices, it is necessary to quantify the changes in the performance parameters of gallium nitride devices caused by these traps. The existing technology measures the changes in the performance parameters of gallium nitride devices caused by traps by applying a periodic voltage signal to the source or gate of the gallium nitride device, and then obtains the defect parameters of the gallium nitride device based on the changes in the performance parameters. However, there are also many electron or hole traps in the epitaxial growth of the channel layer of gallium nitride devices, and the capture of electrons or holes by these traps will also cause changes in the performance parameters of gallium nitride devices. Therefore, the defect parameters of gallium nitride devices cannot be accurately measured by the existing technology method. Summary of the Invention

[0004] In view of this, the embodiments of this application provide a method, device, and medium for measuring defect parameters of a gallium nitride device to solve the problem of low accuracy in measuring defect parameters of existing gallium nitride devices.

[0005] In a first aspect, the embodiments of this application provide a method for measuring defect parameters of a gallium nitride device, including:

[0006] Continuously applying a first voltage with a first duration between the gate and the source of the gallium nitride device in the first stage of each first measurement cycle;

[0007] Continuously applying a second voltage with a second duration between the drain and the source of the gallium nitride device in the second stage of each first measurement cycle;

[0008] At the end of the second stage of each of the first measurement cycles, a first leakage current of the source electrode, a second leakage current of the gate electrode, and a third leakage current of the substrate of the gallium nitride device are measured, and a fourth leakage current of the gallium nitride device corresponding to each of the first measurement cycles is determined based on the first leakage current, the second leakage current, and the third leakage current;

[0009] After N of the first measurement cycles, based on the first duration and the fourth leakage current corresponding to each of the first measurement cycles among the N first measurement cycles, a target duration is determined from the first durations corresponding to the N first measurement cycles respectively; wherein, the first durations corresponding to different first measurement cycles among the N first measurement cycles are different;

[0010] After M of the first measurement cycles, based on the first voltage and the fourth leakage current corresponding to each of the first measurement cycles among the M first measurement cycles, a target voltage is determined from the first voltages corresponding to the M first measurement cycles respectively; wherein, the first voltages corresponding to different first measurement cycles among the M first measurement cycles are different;

[0011] After N + M of the first measurement cycles, a plurality of second measurement cycles are performed. During each of the second measurement cycles, the target voltage for the target duration is continuously applied between the gate electrode and the source electrode, and a third voltage is applied between the drain electrode and the source electrode at a first frequency, and the value of a preset performance parameter of the gallium nitride device corresponding to each of the second measurement cycles is measured;

[0012] Based on the values of the preset performance parameter corresponding to each of the second measurement cycles, the value of a preset defect parameter of the gallium nitride device is determined.

[0013] Optionally, the determining the fourth leakage current of the gallium nitride device corresponding to each of the first measurement cycles based on the first leakage current, the second leakage current, and the third leakage current includes:

[0014] Determining the sum of the first leakage current, the second leakage current, and the third leakage current as the fourth leakage current.

[0015] Optionally, the determining the target duration from the first durations corresponding to the N first measurement cycles respectively includes:

[0016] Calculating a first ratio of the fourth leakage current to the first duration corresponding to each of the first measurement cycles among the N first measurement cycles;

[0017] Determining the first duration corresponding to the smallest first ratio as the target duration.

[0018] Optionally, determining the target voltage from the first voltages corresponding to each of the M first measurement periods includes:

[0019] Calculating, for each of the M first measurement periods, a second ratio of the fourth leakage current corresponding to the first measurement period to the first voltage;

[0020] Determining the first voltage corresponding to the smallest second ratio as the target voltage.

[0021] Optionally, determining the value of the preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to each of the second measurement periods includes:

[0022] Determining the change amount of the preset performance parameter based on the values of the preset performance parameters corresponding to each of the second measurement periods;

[0023] Determining the value of the preset defect parameter based on the change amount of the performance parameter.

[0024] Optionally, the value of the preset defect parameter includes the number of traps formed in the gallium nitride device; after continuously applying the target voltage for the target duration between the gate and the source, it further includes:

[0025] Determining the third leakage current of each different region of the substrate;

[0026] Determining the number of traps in the corresponding region based on the third leakage current of each region.

[0027] Optionally, the number of traps in each region is proportional to the third leakage current of the corresponding region.

[0028] In a second aspect, an embodiment of the present application provides a device for measuring defect parameters of a gallium nitride device, including:

[0029] A first test unit, configured to continuously apply a first voltage for a first duration between the gate and the source of the gallium nitride device in a first stage of each first measurement period;

[0030] A second test unit, configured to continuously apply a second voltage for a second duration between the drain and the source of the gallium nitride device in a second stage of each first measurement period;

[0031] A first determination unit, configured to measure, at the end of the second stage of each first measurement period, a first leakage current of the source, a second leakage current of the gate, and a third leakage current of the substrate of the gallium nitride device, and determine the fourth leakage current of the gallium nitride device corresponding to each first measurement period based on the first leakage current, the second leakage current, and the third leakage current;

[0032] A second determination unit, configured to, after N of the first measurement periods, determine a target duration from the first durations corresponding to each of the N first measurement periods based on the first duration and the fourth leakage current corresponding to each first measurement period in the N first measurement periods; wherein, the first durations corresponding to different first measurement periods among the N first measurement periods are different;

[0033] A third determination unit, configured to, after M of the first measurement periods, determine a target voltage from the first voltages corresponding to each of the M first measurement periods based on the first voltage and the fourth leakage current corresponding to each first measurement period in the M first measurement periods; wherein, the first voltages corresponding to different first measurement periods among the M first measurement periods are different;

[0034] A third test unit, after N+M of the first measurement periods, performs a plurality of second measurement periods. During each second measurement period, the target voltage with the target duration is continuously applied between the gate and the source, and a third voltage is applied between the drain and the source at a first frequency, and the value of the preset performance parameter of the gallium nitride device corresponding to each second measurement period is measured;

[0035] A fourth determination unit, configured to determine the value of the preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to each of the second measurement periods.

[0036] In a third aspect, an embodiment of the present application provides a device for measuring defect parameters of a gallium nitride device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The device is characterized in that when the processor executes the computer program, the steps in the defect parameter measurement method according to any one of the above first aspects are implemented.

[0037] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the steps in the method according to any one of the optional manners of the above first aspect are implemented.

[0038] In a fifth aspect, an embodiment of the present application provides a computer program product, and when the computer program product runs on an audio device, the audio device is caused to execute the steps in the method according to the above first aspect or any one of the optional manners of the first aspect.

[0039] The defect parameter measurement method, device, computer-readable storage medium, and computer program product for a gallium nitride device provided by the embodiments of the present application have the following beneficial effects:

[0040] The method for measuring defect parameters of a gallium nitride device provided by an embodiment of the present application includes continuously applying a first voltage with a first duration between the gate and the source of the gallium nitride device in a first stage of each first measurement period; continuously applying a second voltage with a second duration between the drain and the source of the gallium nitride device in a second stage of each first measurement period; at the end of the second stage of each first measurement period, measuring a first leakage current of the source, a second leakage current of the gate, and a third leakage current of the substrate of the gallium nitride device, and determining a fourth leakage current corresponding to each first measurement period based on the first leakage current, the second leakage current, and the third leakage current; after N first measurement periods, determining a target duration from the first durations corresponding to each of the N first measurement periods based on the first duration and the fourth leakage current corresponding to each first measurement period among the N first measurement periods; after M first measurement periods, determining a target voltage from the first voltages corresponding to each of the M first measurement periods based on the first voltage and the fourth leakage current corresponding to each first measurement period among the M first measurement periods; after N + M first measurement periods, performing a plurality of second measurement periods. In each second measurement period, continuously applying the target voltage with the target duration between the gate and the source, applying a third voltage between the drain and the source at a first frequency, and measuring the value of a preset performance parameter of the gallium nitride device corresponding to each second measurement period; and determining the value of the preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to each second measurement period. In this solution, the target voltage with the target duration is continuously applied between the gate and the source in each second measurement period. Since the charging state of the trap is fixed under the same charging conditions, this solution can fix the charging state of the trap before measuring the value of the preset defect parameter, and then apply the third voltage between the drain and the source at the first frequency to measure the value of the preset defect parameter after fixing the charging state of the trap. Compared with the traditional method for measuring defect parameters of a gallium nitride device, it can be free from the influence of traps that occur during epitaxy of the gallium nitride device, and improve the measurement accuracy of the defect parameters of the gallium nitride device. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 It is a schematic diagram of the distribution of traps in the gallium nitride device provided by the embodiment of the present application;

[0043] Figure 2Schematic diagram of the distribution of traps in a gallium nitride device provided in another embodiment of the present application;

[0044] Figure 3 Schematic flowchart of a method for measuring defect parameters of a gallium nitride device provided in an embodiment of the present application;

[0045] Figure 4 Relationship curve diagram of a fourth leakage current and a first duration provided in an embodiment of the present application;

[0046] Figure 5 Relationship curve diagram of a fourth leakage current and a first voltage provided in an embodiment of the present application;

[0047] Figure 6 Schematic flowchart of a method for measuring defect parameters of a gallium nitride device provided in another embodiment of the present application;

[0048] Figure 7 Schematic structural diagram of a device for measuring defect parameters of a gallium nitride device provided in an embodiment of the present application;

[0049] Figure 8 Schematic structural diagram of a device for measuring defect parameters of a gallium nitride device provided in another embodiment of the present application. Detailed implementation manners

[0050] It should be noted that the terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application, rather than to limit the present application. In the description of the embodiments of the present application, unless otherwise specified, "a plurality of" means two or more than two, "at least one", "one or more" means one, two or more than two. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0051] Referring to "one embodiment" or "some embodiments" described in this specification means that specific features, structures or characteristics described in conjunction with the embodiment are included in one or more embodiments of the present application. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" and the like appearing in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0052] Please refer to Figure 1 ,Figure 1 A schematic diagram of the distribution of traps in a gallium nitride device provided by an embodiment of the present application is shown as Figure 1 shown. The gallium nitride device may include a substrate 111, a buffer layer 112, a gallium nitride layer channel layer 113, an aluminum gallium nitride layer 114, a source electrode 115, a gate electrode 116, a drain electrode 117, and a two-dimensional electron gas 118.

[0053] Among them, the buffer layer 112, the gallium nitride channel layer 113, and the aluminum gallium nitride layer 114 are disposed on the substrate and are arranged in sequence in a direction away from the substrate 111. The buffer layer 112 is in contact with the substrate 111, the gallium nitride layer channel layer 113 is in contact with the buffer layer 112, the aluminum gallium nitride layer 114 is in contact with the gallium nitride layer channel layer 113, the source electrode 115, the gate electrode 116, and the drain electrode 117 are in contact with the aluminum gallium nitride layer 114, and the two-dimensional electron gas 118 is located between the gallium nitride layer channel layer 113 and the aluminum gallium nitride layer 114.

[0054] As Figure 1 shown, there will be many traps of electrons or holes (such as trap a of electrons and trap b of holes) at the contact surface between the source electrode 115 and the aluminum gallium nitride layer 114, the contact surface between the gate electrode 116 and the aluminum gallium nitride layer 114, the contact surface between the source electrode 117 and the aluminum gallium nitride layer 114, and around the two-dimensional electron gas 118. These traps will cause changes in the performance parameters of the gallium nitride device. In order to evaluate the influence of the traps on the gallium nitride device, it is necessary to quantify the changes in the performance parameters of the gallium nitride device caused by these traps.

[0055] The prior art measures the changes in the performance parameters of the gallium nitride device caused by traps by applying a periodic voltage signal to the source electrode or the gate electrode of the gallium nitride device, and then obtains the defect parameters of the gallium nitride device based on the changes in the performance parameters. However, there will also be many traps of electrons or holes in the channel layer of the gallium nitride device during epitaxy. Please refer to Figure 2 , Figure 2 A schematic diagram of the distribution of traps in a gallium nitride device is shown as Figure 2 shown. There will also be many traps of electrons or holes (such as trap c of electrons and trap d of holes) in the gallium nitride layer channel layer 113 of the gallium nitride device during epitaxy. The capture of electrons or holes by these traps will also cause changes in the performance parameters of the gallium nitride device. Therefore, the defect parameters of the gallium nitride device cannot be accurately measured by the method of the prior art.

[0056] Based on this, the embodiments of the present application first provide a method for measuring defect parameters of a gallium nitride device, which can fix the charging state of traps before measuring the value of preset defect parameters, and then apply a third voltage between the drain and the source at a first frequency to measure the value of the preset defect parameters after fixing the charging state of the traps. Compared with the traditional method for measuring defect parameters of a gallium nitride device, it can be free from the influence of traps that appear during the epitaxy of the gallium nitride device, and improve the measurement accuracy of the defect parameters of the gallium nitride device.

[0057] The execution subject of a method for measuring defect parameters of a gallium nitride device provided by the embodiments of the present application can be a defect parameter measurement device of the gallium nitride device, and this defect parameter measurement device is used to execute each step in the subsequent method embodiments.

[0058] Please refer to Figure 3 , Figure 3 which is a schematic flowchart of a method for measuring defect parameters of a gallium nitride device provided by the embodiments of the present application. This method for measuring defect parameters of the gallium nitride device may include S301 to S307, which are described in detail as follows:

[0059] In S301, a first voltage is continuously applied between the gate and the source of the gallium nitride device for a first duration in the first stage of each first measurement cycle.

[0060] In S302, a second voltage is continuously applied between the drain and the source of the gallium nitride device for a second duration in the second stage of each first measurement cycle.

[0061] In S303, at the end of the second stage of each first measurement cycle, a first leakage current of the source of the gallium nitride device, a second leakage current of the gate of the gallium nitride device, and a third leakage current of the substrate of the gallium nitride device are measured, and a fourth leakage current of the gallium nitride device corresponding to each first measurement cycle is determined based on the first leakage current, the second leakage current, and the third leakage current.

[0062] In the embodiments of the present application, in order to fix the charging state of traps that appear in the gallium nitride device, the defect parameter measurement device can be controlled to perform multiple first measurement cycles to determine the target duration and target voltage for charging the gallium nitride device. Then, when charging the gallium nitride device, the charging voltage of the gallium nitride device is maintained at the target voltage, and the charging duration of the gallium nitride device is set to the target duration, so as to fix the charging state of traps that appear in the gallium nitride device.

[0063] Among them, each first measurement period may include a first stage and a second stage. The second stage is located after the first stage and is continuous with the first stage in time, that is, the end time of the first stage may be the start time of the second stage. In addition, the start time of the first stage may be the start time of the first measurement period, and the end time of the second stage may be the end time of the first measurement period.

[0064] The duration of the first stage may be a first duration, and the duration of the second stage may be a second duration. Based on this, the duration of each first measurement period may be the sum of the first duration and the second duration. Among them, both the first duration and the second duration may be set according to actual needs, and no special limitation is made here.

[0065] The first stage is the stage where the defect parameter measurement device applies a first voltage between the gate and the source of the gallium nitride device, and the second stage is the stage where the defect parameter measurement device applies a second voltage between the drain and the source of the gallium nitride device. That is, the defect parameter measurement device may enter the first stage after the start of each first measurement period. During the first stage, a first voltage is continuously applied between the gate and the source of the gallium nitride device for a first duration, and then the first stage ends and enters the second stage; during the second stage, the defect parameter measurement device may continuously apply a second voltage between the drain and the source of the gallium nitride device for a second duration, and then the second stage ends; after the second stage ends, the defect parameter measurement device may measure the first leakage current of the source of the gallium nitride device, the second leakage current of the gate of the gallium nitride device, and the third leakage current of the substrate of the gallium nitride device, and determine the fourth leakage current of the gallium nitride device corresponding to each first measurement period based on the first leakage current, the second leakage current, and the third leakage current; then the current first measurement period ends. The defect parameter measurement device may enter the next first measurement period and repeat the above process.

[0066] Among them, both the first voltage and the second voltage may be set according to actual needs, and no special limitation is made here.

[0067] The third leakage current of the substrate of the gallium nitride device is the third leakage current at a preset position of the substrate of the gallium nitride device.

[0068] In a possible implementation manner, the defect parameter measurement device may determine the sum of the first leakage current, the second leakage current, and the third leakage current as the fourth leakage current.

[0069] In a specific application, in order to obtain the target duration for charging the gallium nitride device, the defect parameter measurement device can be controlled to perform N first measurement cycles, and the first duration of the first stage of each measurement cycle in the N first measurement cycles can be controlled to be different, the second duration of the second stage of each measurement cycle in the N first measurement cycles can be controlled to be the same, the first voltage applied between the gate and the source of the gallium nitride device in the first stage of each measurement cycle in the N first measurement cycles can be controlled to be the same, and the second voltage applied between the drain and the source of the gallium nitride device in the second stage of each measurement cycle in the N first measurement cycles can be controlled to be the same. Based on this, the defect parameter measurement device can obtain the target duration for charging the gallium nitride device by executing S304.

[0070] In a specific application, in order to obtain the target voltage for charging the gallium nitride device, the defect parameter measurement device can be controlled to perform M first measurement cycles, and the first voltage applied between the gate and the source of the gallium nitride device in the first stage of each measurement cycle in the M first measurement cycles can be controlled to be different, the second voltage applied between the drain and the source of the gallium nitride device in the second stage of each measurement cycle in the M first measurement cycles can be controlled to be the same. The first duration of the first stage of each measurement cycle in the M first measurement cycles can be controlled to be the same, and the second duration of the second stage of each measurement cycle in the M first measurement cycles can be controlled to be the same. Based on this, the defect parameter measurement device can obtain the target voltage for charging the gallium nitride device by executing S304.

[0071] Among them, both N and M can be set according to actual needs, and no special limitation is made here.

[0072] In S304, after N of the first measurement cycles, based on the first duration and the fourth drain current corresponding to each first measurement cycle among the N first measurement cycles, the target duration is determined from the first durations corresponding to the N first measurement cycles.

[0073] In a possible implementation manner, after N first measurement cycles, and after obtaining the fourth drain current corresponding to each of the N first measurement cycles respectively, the defect parameter measurement device can calculate the first ratio of the fourth drain current to the first duration corresponding to each first measurement cycle among the N first measurement cycles, obtain N first ratios, and determine the first duration corresponding to the smallest first ratio among the N first ratios as the target duration.

[0074] Exemplarily, after obtaining the fourth drain current corresponding to each of the N first measurement cycles, the defect parameter measurement device can draw a relationship curve graph of the fourth drain current and the first duration based on the fourth drain current and the first duration corresponding to each of the N first measurement cycles. Please refer to Figure 4 , Figure 4A relationship curve between the fourth leakage current and the first duration provided by an embodiment of the present application Figure 4 The slope of the shown curve is the first ratio of the fourth leakage current to the first duration. It can be seen that when the first ratio is the smallest, the slope of the corresponding curve is the smallest, and when the first ratio is the smallest, the fourth leakage current does not change significantly with the change of the first duration and reaches a stable state. Exemplarily, Figure 4 Point A in Figure 4 is the minimum value among N first ratios. Therefore, the first duration B corresponding to point A in

[0075] can be determined as the target duration.

[0075] In S305, after M first measurement cycles, based on the first voltage and the fourth leakage current corresponding to each of the M first measurement cycles, a target voltage is determined from the first voltages corresponding to the M first measurement cycles.

[0076] In a possible implementation manner, after M first measurement cycles, and after obtaining the fourth leakage current corresponding to each of the M first measurement cycles respectively, the defect parameter measurement device may calculate the second ratio of the fourth leakage current to the first voltage corresponding to each of the M first measurement cycles, obtain M second ratios, and determine the first voltage corresponding to the smallest second ratio among the M second ratios as the target voltage.

[0077] Exemplarily, after obtaining the fourth leakage current corresponding to each of the M first measurement cycles, the defect parameter measurement device may draw a relationship curve between the fourth leakage current and the first voltage based on the fourth leakage current and the first voltage corresponding to each of the M first measurement cycles. Please refer to Figure 5 , Figure 5 A relationship curve between the fourth leakage current and the first voltage provided by an embodiment of the present application Figure 5 The slope of the shown curve is the second ratio of the fourth leakage current to the first voltage. It can be seen that when the second ratio is the smallest, the slope of the corresponding curve is the smallest, and when the second ratio is the smallest, the fourth leakage current does not change significantly with the change of the first voltage and reaches a stable state. Exemplarily, Figure 5 Point C in Figure 5 is the minimum value among M second ratios. Therefore, the first voltage D corresponding to point C in

[0078] In S306, after N + M first measurement cycles, multiple second measurement cycles are performed. In each second measurement cycle, the target voltage with the target duration is continuously applied between the gate and the source, and a third voltage is applied between the drain and the source at a first frequency, and the value of the preset performance parameter of the gallium nitride device corresponding to each second measurement cycle is measured.

[0079] In an embodiment of the present application, after N + M first measurement cycles, a target duration and a target voltage are obtained, and the traps in the gallium nitride device are charged based on the target duration and the target voltage. Since the charging state of the traps is fixed under the same charging conditions, therefore, by continuously applying the target voltage with the target duration between the gate and the source in each second measurement cycle, the charging state of the traps can be fixed.

[0080] In an embodiment of the present application, the purpose of performing the second measurement cycle is to measure the value of the preset performance parameter of the gallium nitride device caused by the traps after the charging state of the traps is fixed, and determine the value of the preset defect parameter of the gallium nitride device based on the value of the preset performance parameter corresponding to the second measurement cycle. Among them, the number of cycles of the second measurement cycle can be set according to actual needs and is not limited here.

[0081] In a specific application, the first frequency and the third voltage in different second measurement cycles can be set to be different, and both the first frequency and the third voltage can be set according to actual needs and are not limited here.

[0082] The start time of the second measurement cycle can be the start time of applying the target voltage with the target duration, and the end time of the second measurement cycle can be the end time of applying the third voltage between the drain and the source.

[0083] The preset performance parameters of the gallium nitride device can include but are not limited to the threshold voltage, leakage current magnitude, breakdown voltage, on-resistance, etc. of the gallium nitride device.

[0084] Based on this, at the end of each second measurement cycle, the threshold voltage, leakage current magnitude, breakdown voltage, on-resistance, etc. of the gallium nitride device corresponding to each second measurement cycle can be measured and recorded.

[0085] In S307, based on the values of the preset performance parameters corresponding to each of the second measurement cycles, determine the value of the preset defect parameter of the gallium nitride device.

[0086] In a possible implementation manner, S307 may include the following steps:

[0087] Step a: Based on the values of the preset performance parameters corresponding to each of the second measurement cycles, determine the change amount of the preset performance parameter.

[0088] Optionally, the preset performance parameter can be the threshold voltage. Based on this, the defect parameter measuring device can determine the change amount of the threshold voltage based on the threshold voltages corresponding to each second measurement cycle.

[0089] Exemplarily, if the first threshold voltage measured at the end of the first second measurement period is a volts, and the second threshold voltage measured at the end of the second second measurement period is b volts, then the absolute value of b minus a can be determined as the change amount of the threshold voltage.

[0090] Step b: Determine the value of the preset defect parameter based on the change amount of the preset performance parameter.

[0091] Optionally, the defect parameter measuring device can determine the change amount of the preset performance parameter as the value of the preset defect parameter.

[0092] Exemplarily, when the preset performance parameter is the threshold voltage, the defect parameter measuring device can determine the change amount of the threshold voltage as the value of the preset defect parameter.

[0093] As can be seen from the above, by continuously applying a first voltage with a first duration between the gate and the source of the gallium nitride device in the first stage of each first measurement period; continuously applying a second voltage with a second duration between the drain and the source of the gallium nitride device in the second stage of each first measurement period; at the end of the second stage of each first measurement period, measuring a first leakage current of the source, a second leakage current of the gate, and a third leakage current of the substrate of the gallium nitride device, and determining a fourth leakage current corresponding to each first measurement period based on the first leakage current, the second leakage current, and the third leakage current; after N first measurement periods, based on the first duration and the fourth leakage current corresponding to each first measurement period among the N first measurement periods, determining a target duration from the first durations corresponding to the N first measurement periods; after M first measurement periods, based on the first voltage and the fourth leakage current corresponding to each first measurement period among the M first measurement periods, determining a target voltage from the first voltages corresponding to the M first measurement periods; after N+M first measurement periods, performing a plurality of second measurement periods, and in each second measurement period, continuously applying the target voltage with the target duration between the gate and the source, applying a third voltage between the drain and the source at a first frequency, and measuring the value of a preset performance parameter of the gallium nitride device corresponding to each second measurement period; and determining the value of a preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to each second measurement period. In this solution, the target voltage with the target duration is continuously applied between the gate and the source in each second measurement period. Since the charging state of the trap is fixed under the same charging conditions, this solution can fix the charging state of the trap before measuring the value of the preset defect parameter, and then apply the third voltage between the drain and the source at the first frequency to measure the value of the preset defect parameter after fixing the charging state of the trap. Compared with the traditional method for measuring the defect parameters of gallium nitride devices, it can be unaffected by the traps that occur during the epitaxy of gallium nitride devices, and improves the measurement accuracy of the defect parameters of gallium nitride devices.

[0094] Please refer to Figure 6 , Figure 6 which is a schematic flowchart of a method for measuring defect parameters of a gallium nitride device provided in another embodiment of the present application. As Figure 6 shown, the difference between the method for measuring defect parameters of the gallium nitride device provided in this embodiment and the method for measuring defect parameters of the gallium nitride device provided in Figure 2 is that the value of the preset defect parameter in this embodiment includes the number of traps formed by the gallium nitride device; after continuously applying the target voltage with the target duration between the gate and the source, the method for measuring defect parameters of the gallium nitride device in this embodiment further includes S601 to 602.

[0095] In S601, determine the third leakage current of each different region of the substrate.

[0096] In an embodiment of the present application, after continuously applying a target voltage between the gate and the source for a target duration, the third leakage current of each different region of the substrate can be detected.

[0097] Exemplarily, the substrate can be divided into a first region, a second region, and a third region. Among them, the first region can be the innermost circle of the substrate, the second region can be the region between the innermost circle and the outermost circle of the substrate, and the third region can be the outermost circle of the substrate. Based on this, the first-region leakage current of the first region of the substrate, the second-region leakage current of the second region of the substrate, and the third-region leakage current of the third region of the substrate can be measured respectively. The division method of each different region of the substrate can be set according to actual needs, and no special limitation is made here.

[0098] In S602, the number of traps in the corresponding region is determined based on the third leakage current of each region.

[0099] In an embodiment of the present application, the number of traps in each region is proportional to the third leakage current of the corresponding region. The number of traps in the corresponding region can be determined based on the third leakage current of each region.

[0100] As an example but not a limitation, when the third-region leakage current is the largest, the second-region leakage current is the second largest, and the first-region leakage current is the smallest, it can be determined that the number of traps in the gallium nitride device region corresponding to the third region of the substrate is the largest, that is, the number of traps in the outer ring of the gallium nitride device is the largest; it can be determined that the number of traps in the gallium nitride device region corresponding to the second region of the substrate is the second largest, that is, the number of traps in the region between the outer ring and the inner ring of the gallium nitride device is the second largest; it can be determined that the number of traps in the gallium nitride device region corresponding to the first region of the substrate is the smallest, that is, the number of traps in the inner ring of the gallium nitride device is the smallest.

[0101] Based on Figure 3 the method for measuring the defect parameters of a gallium nitride device provided by the corresponding embodiment, the embodiment of the present application further provides a device for measuring the defect parameters of a gallium nitride device for implementing the above method embodiment. Please refer to Figure 7 , Figure 7 shows a schematic structural diagram of a device for measuring the defect parameters of a gallium nitride device provided by an embodiment of the present application. As Figure 7 shown, the defect parameter measurement device 70 may include: a first test unit 71, a second test unit 72, a first determination unit 73, a second determination unit 74, a third determination unit 75, a third test unit 76, and a fourth determination unit 77. Among them:

[0102] The first test unit 71 is configured to continuously apply a first voltage for a first duration between the gate and the source of the gallium nitride device in the first stage of each first measurement cycle.

[0103] The second test unit 72 is configured to continuously apply a second voltage for a second duration between the drain and the source of the gallium nitride device during the second stage of each of the first measurement periods.

[0104] The first determination unit 73 is configured to measure, at the end of the second stage of each of the first measurement periods, a first leakage current of the source, a second leakage current of the gate, and a third leakage current of the substrate of the gallium nitride device, and determine a fourth leakage current corresponding to each of the first measurement periods based on the first leakage current, the second leakage current, and the third leakage current.

[0105] The second determination unit 74 is configured to, after N of the first measurement periods, determine a target duration from the first durations corresponding to the N first measurement periods based on the first duration and the fourth leakage current corresponding to each of the N first measurement periods; wherein, the first durations corresponding to different first measurement periods among the N first measurement periods are different.

[0106] The third determination unit 75 is configured to, after M of the first measurement periods, determine a target voltage from the first voltages corresponding to the M first measurement periods based on the first voltage and the fourth leakage current corresponding to each of the M first measurement periods; wherein, the first voltages corresponding to different first measurement periods among the M first measurement periods are different.

[0107] The third test unit 76 is configured to, after N + M of the first measurement periods, perform a plurality of second measurement periods. During each of the second measurement periods, continuously apply the target voltage for the target duration between the gate and the source, apply a third voltage between the drain and the source at a first frequency, and measure the value of a preset performance parameter of the gallium nitride device corresponding to each of the second measurement periods.

[0108] The fourth determination unit 77 is configured to determine the value of a preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to the respective second measurement periods.

[0109] Optionally, the first determination unit 73 is specifically configured to determine the sum of the first leakage current, the second leakage current, and the third leakage current as the fourth leakage current.

[0110] Optionally, the second determination unit 74 is specifically configured to calculate a first ratio of the fourth leakage current corresponding to each of the N first measurement periods to the first duration among the N first measurement periods;

[0111] Determine the first duration corresponding to the smallest first ratio as the target duration.

[0112] Optionally, the third determination unit 75 is specifically configured to calculate, for each of the M first measurement periods, a second ratio of the fourth leakage current corresponding to each first measurement period to the first voltage;

[0113] Determine the first voltage corresponding to the smallest second ratio as the target voltage.

[0114] Optionally, the fourth determination unit 77 is specifically configured to determine a change amount of the preset performance parameter based on values of the preset performance parameter corresponding to the respective second measurement periods;

[0115] Determine a value of the preset defect parameter based on the change amount of the performance parameter.

[0116] Optionally, the defect parameter measurement device 70 may further include: a fifth determination unit and a sixth determination unit.

[0117] Wherein:

[0118] The fifth determination unit is specifically configured to determine the third leakage current of each different region of the substrate.

[0119] The sixth determination unit is specifically configured to determine the number of traps in the corresponding region based on the third leakage current of each region. Wherein, the number of traps in each region is proportional to the third leakage current of the corresponding region.

[0120] It should be noted that for the information interaction, execution process, etc. between the above units, since they are based on the same concept as the method embodiment of the present application, their specific functions and the technical effects brought thereby can be specifically referred to the method embodiment part, and will not be elaborated here.

[0121] Please refer to Figure 8 , Figure 8 which is a schematic structural diagram of another defect parameter measurement device for a gallium nitride device provided by an embodiment of the present application. As Figure 8 shown, the defect parameter measurement device 8 provided in this embodiment may include: a processor 80, a memory 81, and a computer program 82 stored in the memory 81 and executable on the processor 80. For example, a program corresponding to the defect parameter measurement method for a gallium nitride device. When the processor 80 executes the computer program 82, the steps in the method embodiment of the defect parameter measurement method applied to a gallium nitride device are implemented, such as Figure 3 shown in S301 - S307. Or, when the processor 80 executes the computer program 82, the functions of each module / unit in the defect parameter measurement device embodiment of the gallium nitride device are implemented, such as Figure 7 the functions of the units 71 - 79 shown.

[0122] Exemplarily, the computer program 82 can be divided into one or more modules / units, which are stored in the memory 81 and executed by the processor 80 to complete this application. One or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and these instruction segments are used to describe the execution process of the computer program 82 in the electronic device 8. For example, the computer program 82 can be divided into a first test unit, a second test unit, a first determination unit, a second determination unit, a third determination unit, a third test unit, and a fourth determination unit. For the specific functions of each unit, please refer to Figure 7 the relevant descriptions in the corresponding embodiments, which will not be elaborated here.

[0123] Those skilled in the art can understand that Figure 8 this is merely an example of the defect parameter measurement device 8 and does not constitute a limitation on the defect parameter measurement device 8. It may include more or fewer components than those shown in the figure, or combine certain components, or different components.

[0124] The processor 80 can be a central processing unit (CPU), or can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0125] The memory 81 can be an internal storage unit of the defect parameter measurement device 8, such as the hard disk or memory of the defect parameter measurement device 8. The memory 81 can also be an external storage device of the defect parameter measurement device 8, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, or a flash card equipped on the defect parameter measurement device 8, etc. Further, the memory 81 can also include both the internal storage unit and the external storage device of the defect parameter measurement device 8. The memory 81 is used to store computer programs and other programs and data required by the electronic device. The memory 81 can also be used to temporarily store data that has been output or will be output.

[0126] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units is used as an example. In actual applications, the above functions can be allocated to different functional units according to needs, that is, the internal structure of the defect parameter measurement device is divided into different functional units to complete all or part of the functions described above. Each functional unit in the embodiment can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working process of the units in the above system can refer to the corresponding process in the foregoing method embodiment and will not be elaborated here.

[0127] An embodiment of this application also provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the steps in the foregoing method embodiments can be implemented.

[0128] An embodiment of this application provides a computer program product. When the computer program product runs on a terminal device, the terminal device implements the steps in the foregoing method embodiments.

[0129] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0130] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0131] The above embodiments are only used to illustrate the technical solutions of this application, rather than to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included in the protection scope of this application.

Claims

1. A method for measuring defect parameters of a gallium nitride device, characterized in that, it includes: continuously applying a first voltage for a first duration between the gate and the source of the gallium nitride device in the first stage of each first measurement cycle; continuously applying a second voltage for a second duration between the drain and the source of the gallium nitride device in the second stage of each first measurement cycle; at the end of the second stage of each first measurement cycle, measuring a first leakage current of the source, a second leakage current of the gate, and a third leakage current of the substrate of the gallium nitride device, and determining a fourth leakage current of the gallium nitride device corresponding to each first measurement cycle based on the first leakage current, the second leakage current, and the third leakage current; after N first measurement cycles, based on the first duration and the fourth leakage current corresponding to each first measurement cycle among the N first measurement cycles, determining a target duration from the first durations corresponding to the N first measurement cycles respectively; wherein, the first durations corresponding to different first measurement cycles among the N first measurement cycles are different; after M first measurement cycles, based on the first voltage and the fourth leakage current corresponding to each first measurement cycle among the M first measurement cycles, determining a target voltage from the first voltages corresponding to the M first measurement cycles respectively; wherein, the first voltages corresponding to different first measurement cycles among the M first measurement cycles are different; after N + M first measurement cycles, performing a plurality of second measurement cycles. In each second measurement cycle, continuously applying the target voltage for the target duration between the gate and the source, applying a third voltage between the drain and the source at a first frequency, and measuring the value of a preset performance parameter of the gallium nitride device corresponding to each second measurement cycle; determining the value of a preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to each second measurement cycle.

2. The defect parameter measurement method according to claim 1, characterized in that, the determining the fourth leakage current of the gallium nitride device corresponding to each first measurement cycle based on the first leakage current, the second leakage current, and the third leakage current includes: determining the sum of the first leakage current, the second leakage current, and the third leakage current as the fourth leakage current.

3. The defect parameter measurement method according to claim 1, characterized in that, the determining a target duration from the first durations corresponding to the N first measurement cycles respectively includes: calculating a first ratio of the fourth leakage current corresponding to each first measurement cycle to the first duration among the N first measurement cycles; determining the first duration corresponding to the smallest first ratio as the target duration.

4. The defect parameter measurement method according to claim 1, characterized in that, the determining a target voltage from the first voltages corresponding to the M first measurement cycles respectively includes: Calculate a second ratio of the fourth leakage current corresponding to each of the M first measurement periods to the first voltage in the M first measurement periods; Determine the first voltage corresponding to the smallest second ratio as the target voltage.

5. The defect parameter measurement method according to claim 1, characterized in that determining the value of the preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to the respective second measurement periods includes: determining a change amount of the preset performance parameter based on the values of the preset performance parameters corresponding to the respective second measurement periods; determining the value of the preset defect parameter based on the change amount of the preset performance parameter.

6. The defect parameter measurement method according to any one of claims 1 to 5, characterized in that the value of the preset defect parameter includes the number of traps formed in the gallium nitride device; after continuously applying the target voltage for the target duration between the gate and the source, further comprising: determining the third leakage current of each different region of the substrate; determining the number of traps in the corresponding region based on the third leakage current of each region.

7. The defect parameter measurement method according to claim 6, characterized in that the number of traps in each region is proportional to the third leakage current of the corresponding region.

8. A defect parameter measurement device for a gallium nitride device, characterized in that comprising: a first test unit configured to continuously apply a first voltage for a first duration between the gate and the source of the gallium nitride device in a first stage of each first measurement period; a second test unit configured to continuously apply a second voltage for a second duration between the drain and the source of the gallium nitride device in a second stage of each first measurement period; a first determination unit configured to measure a first leakage current of the source, a second leakage current of the gate, and a third leakage current of the substrate of the gallium nitride device at the end of the second stage of each first measurement period, and determine a fourth leakage current of the gallium nitride device corresponding to each first measurement period based on the first leakage current, the second leakage current, and the third leakage current; a second determination unit configured to, after N first measurement periods, determine a target duration from the first durations corresponding to the N first measurement periods based on the first duration and the fourth leakage current corresponding to each first measurement period in the N first measurement periods; wherein, the first durations corresponding to different first measurement periods in the N first measurement periods are different; a third determination unit configured to, after M first measurement periods, determine a target voltage from the first voltages corresponding to the M first measurement periods based on the first voltage and the fourth leakage current corresponding to each first measurement period in the M first measurement periods; wherein, the first voltages corresponding to different first measurement periods in the M first measurement periods are different; The third test unit, after N + M of the first measurement cycles, performs a plurality of second measurement cycles. During each of the second measurement cycles, the target voltage with the target duration is continuously applied between the gate and the source, and a third voltage is applied between the drain and the source at a first frequency, and the values of the preset performance parameters of the gallium nitride device corresponding to each of the second measurement cycles are measured; The fourth determination unit is configured to determine the value of the preset defect parameter of the gallium nitride device based on the values of the preset performance parameters corresponding to each of the second measurement cycles.

9. A defect parameter measurement device for a gallium nitride device, Characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that when the processor executes the computer program, each step in the defect parameter measurement method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, Characterized in that, When the computer program is executed by a processor, each step in the defect parameter measurement method according to any one of claims 1 to 7 is implemented.

Images