Depletion mode GaN HEMT device reliability simulation method under high-power microwave stress condition

Abstract

The invention discloses a depletion mode GaN HEMT device reliability simulation method under a high-power microwave stress condition. The method comprises the following steps: establishing a two-dimensional device structure initial model of a depletion mode GaN HEMT device; performing model parameter correction on the two-dimensional device structure initial model to obtain a two-dimensional device structure calibration model; performing high-power microwave stress applying condition simulation on the two-dimensional device structure calibration model to obtain a temperature change condition and electric field distribution of the two-dimensional device structure calibration model after the high-power microwave pulse is applied; and based on the temperature change condition and the electric field distribution, analyzing the reliability mechanism of the device under the high-power microwave stress condition. By applying the high-power microwave pulse to the two-dimensional device structure calibration model, the instantaneous change conditions of parameters such as temperature, electric field and current of the device in the process can be obtained, and the problem that the temperature and the electric field of the device in the high-power microwave action period are difficult to detect through an experimental method is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor devices, and particularly relates to a reliability simulation method for a depletion-mode GaN HEMT device under high-power microwave stress conditions. BACKGROUND

[0002] The depletion-mode GaN HEMT (High Electron Mobility Transistor) is a high-performance field-effect device based on III-nitride materials. With its wide band gap, high breakdown electric field, high thermal conductivity and high electron saturation velocity, it is widely used in radio frequency communication, radar systems and power electronics in high-frequency, high-power and high-temperature environments. The device forms a high-density two-dimensional electron gas (2DEG) at the interface through an AlGaN / GaN heterostructure, achieving high electron mobility and low on-resistance, thus having excellent power gain and frequency response capability. At the same time, the excellent thermal stability and mechanical strength of GaN material make it have good electrical performance and reliability under harsh working conditions, gradually becoming a new generation of semiconductor power device core technology platform after Si and GaAs.

[0003] The current electromagnetic environment is becoming increasingly complex. The application of depletion-mode GaN HEMT devices in harsh environments such as high-power microwave (HPM), high-power electromagnetic pulse (EMP) and particle irradiation makes the reliability problem increasingly prominent. High-power microwave (HPM) pulses can be coupled to the radio frequency front end through the front door (antenna) and the back door (microstrip line or power line). As a key component of the radio frequency front-end receiving link, HEMT is the most vulnerable part. Excessive microwave pulses injected into the rated power may cause HEMT to be damaged, thereby directly affecting the noise figure and sensitivity of the entire receiving system.

[0004] The high-power microwave pulse action time is very short, and it is difficult to detect the temperature and electric field changes of the device during the high-power microwave action through experimental methods. Through simulation, the temperature and electric field changes of the device during the high-power microwave pulse action can be detected. However, the reliability problem of the depletion-mode GaN HEMT device under high-power microwave stress conditions is complex, and a mature simulation method has not yet been established. SUMMARY

[0005] In order to solve the above problems existing in the prior art, the application provides a reliability simulation method for a depletion-mode GaN HEMT device under high-power microwave stress conditions. The technical problem to be solved by the application is solved through the following technical scheme: This invention provides a reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions, comprising: S1: Establish the initial two-dimensional device structure model of the depletion-mode GaN HEMT device; S2: Correct the model parameters of the initial model of the two-dimensional device structure to obtain the calibration model of the two-dimensional device structure; S3: Simulate the two-dimensional device structure calibration model under high-power microwave stress to obtain the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying high-power microwave stress. S4: Based on the temperature change and electric field distribution, analyze the device reliability mechanism under high-power microwave stress conditions.

[0006] In one embodiment of the present invention, S1 includes: Based on the device structure parameters and the SDE tool of Sentaurus TCAD simulation software, a two-dimensional initial model of the depletion-type GaN HEMT device is established. The device structure parameters include the geometry, size and doping concentration of the depletion-type GaN HEMT device.

[0007] In one embodiment of the present invention, S2 includes: S2.1: The transfer characteristic curve of the initial model of the two-dimensional device structure is obtained by static scanning with gate voltage as the abscissa and drain current as the ordinate; S2.2: Obtain the output characteristic curve of the initial model of the two-dimensional device structure with drain voltage as the abscissa and drain current as the ordinate using static scanning; S2.3: Based on the differences between the transfer characteristic curves and output characteristic curves of the initial model of the two-dimensional device structure and the actual transfer characteristic curves and actual output characteristic curves of the device, the model parameters of the initial model of the two-dimensional device structure are corrected to obtain the corrected two-dimensional device structure calibration model.

[0008] In one embodiment of the present invention, S2.1 includes: During static scanning, the source, drain, gate, and substrate of the initial model of the two-dimensional device structure are all set to 0V. The drain voltage is scanned from 0V to 0.5V. The drain voltage is kept at 0.5V, and the gate voltage is scanned from 0V to -5V to obtain the transfer characteristic curve of the initial model of the two-dimensional device structure with the gate voltage as the abscissa and the drain current as the ordinate.

[0009] In one embodiment of the present invention, S2.2 includes: During static scanning, the source, drain, gate, and substrate of the initial model of the two-dimensional device structure are all set to 0V, and the gate voltage is scanned from 0V to -2V; the gate voltage is kept at -2V, and then the gate voltage is scanned from 0V to 10V to obtain the output characteristic curve of the initial model of the two-dimensional device structure with the drain voltage as the abscissa and the drain current as the ordinate.

[0010] In one embodiment of the present invention, S2.3 includes: The process involves comparing whether the actual transfer characteristic curve of the depletion-mode GaN HEMT device completely coincides with the transfer characteristic curve of the initial model of the two-dimensional device structure, and whether the actual output characteristic curve of the depletion-mode GaN HEMT device completely coincides with the output characteristic curve of the initial model of the two-dimensional device structure. If not, the gate work function, source / drain doping concentration, and Al content in AlGaN of the initial model of the two-dimensional device structure are adjusted. The adjusted device model is then subjected to static scanning to obtain new transfer characteristic curves and output characteristic curves. These new transfer characteristic curves and output characteristic curves are then compared with the actual transfer characteristic curve and actual output characteristic curve, respectively. This process of static scanning and model parameter adjustment is repeated until the actual transfer characteristic curve completely coincides with the transfer characteristic curve of the adjusted device model and the actual output characteristic curve completely coincides with the output characteristic curve of the adjusted device model. The adjusted device model at this point is then used as the calibration model for the two-dimensional device structure.

[0011] In one embodiment of the present invention, S3 includes: S3.1: Define the Device part of the two-dimensional device structure calibration model in the sdevice tool of the Sentaurus TCAD simulation software, and load the two-dimensional device structure calibration model and the corresponding physical model into the Device part; S3.2: Define the circuit system portion in the sdevice tool for applying high-power microwave pulse simulation; S3.3: After setting the Quasistationary and Transient sections in the solve section of the sdevice tool, perform high-power microwave stress simulation. The Quasistationary section includes the static bias voltages of the gate and drain of the two-dimensional device structure calibration model; the Transient section includes the start and end times of the gate pulse and the scan step size of the two-dimensional device structure calibration model. S3.4: Use the svisual tool to extract the simulation results from the sdevice tool to obtain the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying a high-power microwave pulse.

[0012] In one embodiment of the present invention, the physical model includes the SRH model, high-field velocity saturation model, thermodynamic model, piezoelectric polarization model, avalanche breakdown model and band-to-band tunneling model corresponding to the two-dimensional device structure calibration model.

[0013] In one embodiment of the present invention, S3.2 includes: In the circuit system section of the sdevice tool, the gate of the two-dimensional device structure calibration model is connected to a high-power microwave signal source, the substrate is connected to the ground terminal, and the drain is connected to the current limiting circuit and then connected to the power supply terminal to provide a drain bias voltage, thereby forming a circuit model to apply a high-power microwave pulse to the depletion-type GaN HEMT device.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions of this invention establishes an experimentally calibrated two-dimensional device structure model and applies high-power microwave stress to it. This allows for real-time acquisition of multi-physics dynamic response information of the device under extreme stress conditions, including key parameters such as transient temperature distribution, electric field intensity changes, and current density evolution. This method effectively solves the problem that the duration of high-power microwave stress is extremely short, and traditional experimental methods are insufficient to capture transient parameters within the device in real time. It provides a powerful simulation tool for a deeper understanding of the degradation mechanism of devices under high-power microwave stress. Based on the comparison and verification of simulation and experimental results, this method can accurately identify sensitive regions in the device and their potential damage mechanisms, providing an important basis for the design and optimization of high-reliability GaN HEMT devices.

[0015] 2. The simulation method proposed in this invention possesses excellent scalability and multiphysics coupling analysis capabilities, comprehensively considering the electro-thermal multi-field coupling effect to achieve a comprehensive simulation of the reliability behavior of devices under complex microwave stress environments. By setting different microwave stress conditions such as power, frequency, and pulse width, the influence of various operating parameters on device performance degradation can be systematically studied, thereby establishing a physics-based damage model and lifetime prediction method, providing theoretical support and data foundation for reliability assessment and failure protection of devices in practical applications.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a flowchart of a reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions, provided by an embodiment of the present invention. Figure 2This is a schematic diagram of the initial two-dimensional device structure of a depletion-mode GaN HEMT established by TCAD simulation software according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the transfer characteristic curve of a device structure calibration model and the actual transfer characteristic curve of the device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the output characteristic curve of a device structure calibration model and the actual output characteristic curve of the device provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of a circuit model constructed in simulation software according to an embodiment of the present invention; Figure 6 This is a temperature change curve of a two-dimensional device structure calibration model under high-power microwave stress, provided in an embodiment of the present invention. Figure 7 This is a hot spot location of a two-dimensional device structure calibration model provided in this embodiment of the invention under high-power microwave stress. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following describes in detail, with reference to the accompanying drawings and specific embodiments, a reliability simulation method for depletion-type GaN HEMT devices under high-power microwave stress conditions proposed according to the present invention.

[0019] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element.

[0021] This embodiment provides a reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions. This simulation method is implemented based on Sentaurus TCAD simulation software. Please refer to... Figure 1 , Figure 1 This is a flowchart of a reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions, provided by an embodiment of the present invention. Figure 1 As shown, the simulation method includes: S1: Establish the initial two-dimensional device structure model of the depletion-mode GaN HEMT device.

[0022] In this embodiment, step S1 includes: establishing an initial two-dimensional device structure model of the depletion-mode GaN HEMT device based on the device structure parameters and the sde tool of the Sentaurus TCAD simulation software. Optionally, the device structure parameters include the geometry, size, and doping concentration of the depletion-mode GaN HEMT device.

[0023] For example, please see Figure 2 , Figure 2 This is a schematic diagram of the initial two-dimensional device structure of a depletion-mode GaN HEMT established using TCAD simulation software according to an embodiment of the present invention. The initial two-dimensional device structure model of this embodiment includes a SiC substrate, a GaN layer, an AlGaN layer, a source, a drain, a gate, a Si3N4 passivation layer, and a field plate. The SiC substrate, GaN layer, and AlGaN layer are stacked sequentially from bottom to top. The source and drain are respectively located on the left and right sides of the upper surface of the AlGaN layer. The gate is located on the upper surface of the AlGaN layer and spaced between the source and drain. In this embodiment, the gate has a T-shaped cross-section. Further, the upper surfaces of the source, drain, and gate, the upper surface of the AlGaN layer between the source and gate, and the upper surface of the AlGaN layer between the drain and gate are all covered with a Si3N4 passivation layer. A field plate is disposed on the Si3N4 passivation layer above the gate, separated from the gate by the Si3N4 passivation layer, and one end of the field plate is connected to the source.

[0024] S2: Correct the model parameters of the initial model of the two-dimensional device structure to obtain the calibration model of the two-dimensional device structure.

[0025] In this embodiment, step S2 specifically includes: S2.1: Obtain the transfer characteristic curve of the initial model of the two-dimensional device structure with gate voltage as the abscissa and drain current as the ordinate using static scanning.

[0026] Specifically, during static scanning, the source, drain, gate, and substrate of the initial two-dimensional device structure model are all grounded, i.e., set to 0V. Then, the drain voltage is scanned from 0V to 0.5V. Keeping the drain voltage at 0.5V, the gate voltage is scanned from 0V to -5V to obtain the transfer characteristic curve of the initial two-dimensional device structure model with the gate voltage as the abscissa and the drain current as the ordinate.

[0027] S2.2: Using static scanning, the output characteristic curve of the initial model of the two-dimensional device structure is obtained with drain voltage as the abscissa and drain current as the ordinate.

[0028] Specifically, during static scanning, the source, drain, gate, and substrate of the initial two-dimensional device structure model are all grounded, i.e., set to 0V. The gate voltage is scanned from 0V to -2V. The gate voltage is kept at -2V, and then scanned from 0V to 10V to obtain the output characteristic curve of the initial two-dimensional device structure model with the drain voltage as the horizontal axis and the drain current as the vertical axis.

[0029] S2.3: Based on the differences between the transfer characteristic curves and output characteristic curves of the initial model of the two-dimensional device structure and the actual transfer characteristic curves and actual output characteristic curves of the device, the model parameters of the initial model of the two-dimensional device structure are corrected to obtain the corrected two-dimensional device structure calibration model. The model parameters include: gate work function, source / drain doping concentration, and Al content in AlGaN.

[0030] Specifically, the actual transfer characteristic curve of the depletion-mode GaN HEMT device is compared with the transfer characteristic curve of the initial model of the two-dimensional device structure, and the actual output characteristic curve of the depletion-mode GaN HEMT device is compared with the output characteristic curve of the initial model of the two-dimensional device structure. If not, the gate work function, source / drain doping concentration, and Al content in AlGaN of the initial model of the two-dimensional device structure are adjusted. The adjusted device model is then subjected to static scanning to obtain new transfer characteristic curves and output characteristic curves. The new transfer characteristic curves and output characteristic curves are then compared with the actual transfer characteristic curves and actual output characteristic curves, respectively. The static scanning and model parameter adjustment process is repeated until the actual transfer characteristic curve and the actual output characteristic curve of the adjusted device model are completely coincident. The adjusted device model at this point is used as the calibration model of the two-dimensional device structure.

[0031] It should be noted that the actual transfer characteristic curves and actual output characteristic curves of depletion-mode GaN HEMT devices can be obtained experimentally.

[0032] For example, the model parameters of the two-dimensional device structure calibration model of the depletion-mode GaN HEMT are shown in Table 1. Please refer to Table 1 for further details. Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the transfer characteristic curve of a device structure calibration model and the actual transfer characteristic curve of the device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the output characteristic curve of a device structure calibration model and the actual output characteristic curve of the device provided in an embodiment of the present invention. From Figure 3 and Figure 4 As can be seen, the transfer characteristic curve of the calibrated two-dimensional device structure calibration model is basically consistent with the actual transfer characteristic curve of the device. Similarly, the output characteristic curve of the calibrated two-dimensional device structure calibration model is basically consistent with the actual output characteristic curve of the device.

[0033] Table 1. Model parameters of the two-dimensional device structure calibration model

[0034] S3: Simulate the two-dimensional device structure calibration model under high-power microwave stress to obtain the temperature change and electric field distribution of the device after applying high-power microwave stress.

[0035] In an optional embodiment, S3 includes: S3.1: Define the Device part of the two-dimensional device structure calibration model in sdevice, and load the two-dimensional device structure calibration model and the corresponding physical model into the Device part.

[0036] In this embodiment, the physical models include: SRH (Shockley-Read-Hall) model, high-field velocity saturation model, thermodynamic model, piezoelectric polarization model, avalanche breakdown model, and band-to-band tunneling model.

[0037] Specifically, first, a two-dimensional device structure calibration model is added to the Device section. The File, Electrode, Plot, and Physics sections are set up in the Device section. The File section includes the added two-dimensional device structure calibration model, the Physics section includes the physical model corresponding to the two-dimensional device structure calibration model, and the Electrode section includes the electrodes.

[0038] S3.2: Define the circuit system portion in the sdevice tool for applying high-power microwave pulse simulation.

[0039] In this embodiment, in the circuit system section of the sdevice tool, the source, drain, substrate, and gate of the two-dimensional device structure calibration model are numbered s, d, b, and g, respectively. The gate is connected to the HPM signal source (High Power Microwave Signal Source), the substrate is connected to the ground terminal, and the drain is connected to the power supply terminal after being connected to the current limiting circuit to provide the drain bias voltage, forming a circuit model for applying high-power microwave pulses to the depletion-mode GaN HEMT device. In this embodiment, the current limiting circuit is a resistor. Please refer to [link to relevant documentation]. Figure 5 , Figure 5 This is a schematic diagram of a circuit model constructed in simulation software according to an embodiment of the present invention, and its setting command statements are as follows:

[0040] Where v0 is the initial voltage of the signal, va is the signal amplitude, freq is the signal frequency, td is the initial voltage holding time, and theta is the signal attenuation coefficient.

[0041] S3.3: After setting the Quasistationary and Transient sections in the solve section of the sdevice tool, perform a simulation of applying high-power microwave stress.

[0042] Optionally, the Quasistationary section includes the gate and drain static bias voltages of the two-dimensional device structure calibration model. In this embodiment, the gate bias voltage Vgs of the two-dimensional device structure calibration model is set to -2.3V, and the drain bias voltage Vd is set to 10V.

[0043] Optionally, the Transient portion includes the start and end times of the gate pulse and the scan step size of the two-dimensional device structure calibration model.

[0044] S3.4: Use the svisual tool to extract the simulation results from the sdevice tool to obtain the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying a high-power microwave pulse.

[0045] In this embodiment, after extracting the temperature characteristic parameters from the simulation results of applying high-power microwave stress in sdevice using the svisual tool, the temperature change and temperature distribution of the device after applying high-power microwave stress can be plotted.

[0046] S4: Based on the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying high-power microwave pulses, the reliability mechanism of the device under high-power microwave stress conditions is analyzed.

[0047] Specifically, the reliability mechanism of the device is determined by analyzing the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying high-power microwave stress.

[0048] Furthermore, taking the two-dimensional device structure calibration model of GaN HEMT as an example, the results of the temperature change and temperature distribution of the device after applying high-power microwave stress can be found in [link to relevant documentation]. Figure 6 and Figure 7 ,exist Figure 6 In this context, Tmax represents the highest temperature inside the device. Figure 6 This is a temperature change curve of a two-dimensional device structure calibration model under high-power microwave stress, provided in an embodiment of the present invention. Figure 7 This figure shows the hotspot location of a two-dimensional device structure calibration model provided in this embodiment of the invention under high-power microwave stress. As can be seen from the figure, after applying high-power microwave stress, the temperature waveform near the device gate resembles a sinusoidal signal with a step-like upward trend. The temperature near the device gate gradually accumulates, reaching the melting point of GaN material (1973K), thus causing the device to burn out.

[0049] This invention presents a reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress. By establishing an experimentally calibrated two-dimensional device structure model and applying high-power microwave stress to it, the method can acquire real-time multi-physics dynamic response information of the device under extreme stress conditions, including key parameters such as transient temperature distribution, electric field intensity changes, and current density evolution. This method effectively solves the problem that the duration of high-power microwave stress is extremely short and traditional experimental methods are unable to capture the transient parameters inside the device in real time, providing a powerful simulation tool for a deeper understanding of the degradation mechanism of devices under high-power microwave stress. Based on the comparison and verification of simulation and experimental results, this method can accurately identify sensitive regions in the device and their potential damage mechanisms, providing an important basis for the design and optimization of high-reliability GaN HEMT devices.

[0050] The simulation method proposed in this invention possesses excellent scalability and multiphysics coupling analysis capabilities, comprehensively considering electro-thermal multi-field coupling effects to achieve a complete simulation of the reliability behavior of devices under complex microwave stress environments. By setting different microwave stress conditions such as power, frequency, and pulse width, the influence of various operating parameters on device performance degradation can be systematically studied, thereby establishing a physics-based damage model and lifetime prediction method. This provides theoretical support and a data foundation for reliability assessment and failure prevention of devices in practical applications.

[0051] Another embodiment of the present invention provides a storage medium storing a computer program for executing the steps of the reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions described in the above embodiments. A further aspect of the present invention provides an electronic device including a memory and a processor. The memory stores a computer program, and the processor, when calling the computer program in the memory, implements the steps of the reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions as described in the above embodiments. Specifically, the integrated modules implemented as software functional modules can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0052] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions, characterized in that, include: S1: Establish the initial two-dimensional device structure model of the depletion-mode GaN HEMT device; S2: Correct the model parameters of the initial model of the two-dimensional device structure to obtain the calibration model of the two-dimensional device structure; S3: Simulate the two-dimensional device structure calibration model under high-power microwave stress to obtain the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying high-power microwave stress. S4: Based on the temperature change and electric field distribution, analyze the device reliability mechanism under high-power microwave stress conditions.

2. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 1, characterized in that, S1 includes: Based on the device structure parameters and the SDE tool of Sentaurus TCAD simulation software, a two-dimensional initial model of the depletion-type GaN HEMT device is established. The device structure parameters include the geometry, size and doping concentration of the depletion-type GaN HEMT device.

3. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 1, characterized in that, S2 includes: S2.1: The transfer characteristic curve of the initial model of the two-dimensional device structure is obtained by static scanning with gate voltage as the abscissa and drain current as the ordinate; S2.2: Obtain the output characteristic curve of the initial model of the two-dimensional device structure with drain voltage as the abscissa and drain current as the ordinate using static scanning; S2.3: Based on the differences between the transfer characteristic curves and output characteristic curves of the initial model of the two-dimensional device structure and the actual transfer characteristic curves and actual output characteristic curves of the device, the model parameters of the initial model of the two-dimensional device structure are corrected to obtain the corrected two-dimensional device structure calibration model.

4. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 3, characterized in that, S2.1 includes: During static scanning, the source, drain, gate, and substrate of the initial model of the two-dimensional device structure are all set to 0V. The drain voltage is scanned from 0V to 0.5V. The drain voltage is kept at 0.5V, and the gate voltage is scanned from 0V to -5V to obtain the transfer characteristic curve of the initial model of the two-dimensional device structure with the gate voltage as the abscissa and the drain current as the ordinate.

5. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 3, characterized in that, S2.2 includes: During static scanning, the source, drain, gate, and substrate of the initial model of the two-dimensional device structure are all set to 0V, and the gate voltage is scanned from 0V to -2V; the gate voltage is kept at -2V, and then the gate voltage is scanned from 0V to 10V to obtain the output characteristic curve of the initial model of the two-dimensional device structure with the drain voltage as the abscissa and the drain current as the ordinate.

6. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 3, characterized in that, S2.3 includes: The process involves comparing whether the actual transfer characteristic curve of the depletion-mode GaN HEMT device completely coincides with the transfer characteristic curve of the initial model of the two-dimensional device structure, and whether the actual output characteristic curve of the depletion-mode GaN HEMT device completely coincides with the output characteristic curve of the initial model of the two-dimensional device structure. If not, the gate work function, source / drain doping concentration, and Al content in AlGaN of the initial model of the two-dimensional device structure are adjusted. The adjusted device model is then subjected to static scanning to obtain new transfer characteristic curves and output characteristic curves. These new transfer characteristic curves and output characteristic curves are then compared with the actual transfer characteristic curve and actual output characteristic curve, respectively. This process of static scanning and model parameter adjustment is repeated until the actual transfer characteristic curve completely coincides with the transfer characteristic curve of the adjusted device model and the actual output characteristic curve completely coincides with the output characteristic curve of the adjusted device model. The adjusted device model at this point is then used as the calibration model for the two-dimensional device structure.

7. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 2, characterized in that, S3 includes: S3.1: Define the Device part of the two-dimensional device structure calibration model in the sdevice tool of the Sentaurus TCAD simulation software, and load the two-dimensional device structure calibration model and the corresponding physical model into the Device part; S3.2: Define the circuit system portion in the sdevice tool for applying high-power microwave pulse simulation; S3.3: After setting the Quasistationary and Transient sections in the solve section of the sdevice tool, perform high-power microwave stress simulation. The Quasistationary section includes the static bias voltages of the gate and drain of the two-dimensional device structure calibration model; the Transient section includes the start and end times of the gate pulse and the scan step size of the two-dimensional device structure calibration model. S3.4: Use the svisual tool to extract the simulation results from the sdevice tool to obtain the temperature change and electric field distribution of the two-dimensional device structure calibration model after applying a high-power microwave pulse.

8. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 7, characterized in that, The physical models include the SRH model, high-field velocity saturation model, thermodynamic model, piezoelectric polarization model, avalanche breakdown model, and band-to-band tunneling model corresponding to the two-dimensional device structure calibration model.

9. The reliability simulation method for depletion-mode GaN HEMT devices under high-power microwave stress conditions according to claim 7, characterized in that, S3.2 includes: In the circuit system section of the sdevice tool, the gate of the two-dimensional device structure calibration model is connected to a high-power microwave signal source, the substrate is connected to the ground terminal, and the drain is connected to the current limiting circuit and then connected to the power supply terminal to provide a drain bias voltage, thereby forming a circuit model to apply a high-power microwave pulse to the depletion-type GaN HEMT device.

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