A method and system for characterizing deep level defects of a gallium oxide device, and an electronic device

Abstract

The application provides a gallium oxide device deep level defect characterization method, a system and an electronic device, and relates to the technical field of semiconductor materials.The gallium oxide device deep level defect characterization method comprises the following steps: performing isothermal DLTS testing on a gallium oxide device to obtain an isothermal capacitance-test period curve, and determining the value range of the test period according to the isothermal capacitance-test period curve; performing first DLTS testing on the gallium oxide device based on preset initial experimental parameters to obtain an initial DLTS spectrum; extending the test period within the value range and repeatedly performing DLTS testing on the gallium oxide device according to the initial DLTS spectrum to obtain a final DLTS spectrum; and fitting all defect peaks in the final DLTS spectrum to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.The application improves the detection and characterization accuracy of the defects of the gallium oxide device through progressive testing and accurate fitting.

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, and more specifically, to a method, system, and electronic device for characterizing deep energy level defects in gallium oxide devices. Background Technology

[0002] Gallium oxide ( As a core representative of fourth-generation ultra-wide bandgap semiconductors, gallium oxide (GaO) possesses an ultra-wide bandgap and can be grown into large-size single-crystal wafers using a low-cost melt-forming method. Therefore, GaO is considered an ideal material for fabricating next-generation high-voltage, low-loss power devices. During fabrication, deep-level transient spectroscopy is typically employed to detect low-concentration deep-level defects by monitoring transient signals of capacitance or current, thus enabling the analysis of... Quantitative characterization of the defect spectrum of the device.

[0003] In related technologies, deep-level transient spectroscopy typically employs a fixed short-pulse-width testing mode, which is only effective for simple point defects and is therefore difficult to fully detect. The prevalent extended defects in the device, coupled with the inability to effectively observe high-activation-energy, high-temperature defects, ultimately result in incomplete deep-level transient spectra. A large amount of crucial defect information is missed, making it impossible to obtain complete defect energy levels and trapping cross-section parameters, thus failing to meet the requirements. The need for accurate identification and quantitative analysis of device defects has constrained the progress of material process optimization and device performance improvement. Summary of the Invention

[0004] The problem solved by this invention is how to improve the... The accuracy of characterizing the defect energy levels and concentrations of the device.

[0005] To address the aforementioned problems, this invention provides a method, system, and electronic device for characterizing extremely deep energy level defects in gallium oxide devices.

[0006] In a first aspect, the present invention provides a method for characterizing extremely deep energy level defects in gallium oxide devices, comprising: Isothermal DLTS testing was performed on gallium oxide devices to obtain isothermal capacitance-test period curves, and the range of test period values ​​was determined based on the isothermal capacitance-test period curves. Based on preset initial experimental parameters, the gallium oxide device was subjected to its first DLTS test to obtain an initial DLTS spectrum; Based on the initial DLTS spectrum, the test period is extended within the range of the values, and the DLTS test is repeated on the gallium oxide device to obtain the final DLTS spectrum. All defect peaks in the final DLTS spectrum are fitted to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.

[0007] Optionally, the isothermal DLTS test of the gallium oxide device to obtain the isothermal capacitance-test period curve includes: At a preset constant test temperature, carriers are filled into the defect energy level by forward bias. Within the initial range of the test cycle, the test cycle is gradually adjusted according to preset requirements. The capacitor transient signal is monitored by reverse bias to obtain the capacitance value under different test cycles. The isothermal capacitance-test cycle curve is generated based on the capacitance value and the corresponding test period.

[0008] Optionally, determining the range of values ​​for the test period based on the isothermal capacitance-test period curve includes: Based on the trend of the capacitance value changing with the test period in the isothermal capacitance-test period curve, the key range of the capacitance value is determined; The range of values ​​for the test period is determined based on the upper and lower limits of the critical interval of the capacitance value. The range of values ​​covers the time required for the expansion defect and the carrier filling.

[0009] Optionally, the step of performing the first DLTS test on the gallium oxide device based on preset initial experimental parameters to obtain an initial DLTS spectrum includes: Temperature is controlled according to the temperature scan range and cooling rate in the preset initial experimental parameters, and the transient signal of the capacitor is excited and monitored by applying a reverse bias voltage to the gallium oxide device. Based on the capacitance transient signal, noise reduction and spectrum conversion processing are performed to generate the initial DLTS spectrum.

[0010] Optionally, the step of extending the test period and repeating the DLTS test on the gallium oxide device within the value range based on the initial DLTS spectrum to obtain the final DLTS spectrum includes: The initial DLTS spectrum is analyzed to determine the integrity of the defect peaks in the initial DLTS spectrum; Based on the integrity of the defect peak, the test period is extended within the range of the value, and the gallium oxide device is repeatedly subjected to DLTS test to obtain the intermediate DLTS spectrum after each DLTS test. The changes in defect peaks in the intermediate DLTS spectrum and the initial DLTS spectrum are compared and analyzed until all the defect peaks are obtained, and the spectrum containing all the defect peaks is taken as the final DLTS spectrum.

[0011] Optionally, extending the test cycle within the value range based on the integrity of the defect peak includes: The test cycle is extended within the range of values ​​by extending the time window for defect filling and / or emission.

[0012] Optionally, the step of extending the test cycle within the value range and repeatedly performing DLTS testing on the gallium oxide device based on the defect peak integrity to obtain an intermediate DLTS spectrum after each DLTS test includes: Based on the integrity of the defect peaks, the defect peaks in the initial DLTS spectrum are determined; Within the range of values ​​for the test cycle, the test cycle is extended in a gradually increasing manner, while keeping the reverse bias voltage, temperature scan range, and cooling rate in the preset initial experimental parameters unchanged. The DLTS test is repeated sequentially for each extended test cycle, and the capacitance transient signal of each DLTS test is continuously collected. Based on the capacitor transient signal, the intermediate DLTS spectrum after each DLTS test is generated.

[0013] Optionally, fitting all defect peaks in the final DLTS spectrum to determine the defect energy level and trapping cross section of each defect peak in the final DLTS spectrum includes: The final DLTS spectrum is extracted to obtain the feature parameters of all the defect peaks in the final DLTS spectrum. The feature parameters include the peak position, peak shape profile and peak intensity data of the defect peaks. Substitute the peak position, peak shape profile, and peak intensity data of each defect peak into the fitting model, perform data fitting calculation, and obtain the energy difference and carrier capture probability parameters corresponding to each defect peak; The fitting model is established using the Arrhenius fitting method based on the correlation between temperature and carrier emission time constant. The energy difference is used as the defect energy level of the defect peak, and the carrier capture probability parameter is used as the capture cross section of the defect peak.

[0014] In a second aspect, the present invention provides a gallium oxide device deep energy level defect characterization system, comprising: The testing unit is used to perform isothermal DLTS testing on the gallium oxide device to obtain an isothermal capacitance-test period curve, and to determine the range of test period values ​​based on the isothermal capacitance-test period curve; based on preset initial experimental parameters, the gallium oxide device is subjected to an initial DLTS test to obtain an initial DLTS spectrum; based on the initial DLTS spectrum, the test period is extended within the range of values, and the DLTS test on the gallium oxide device is repeated to obtain a final DLTS spectrum; A fitting unit is used to fit all the defect peaks in the final DLTS spectrum to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.

[0015] Thirdly, an electronic device according to the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the gallium oxide device deep-level defect characterization method as described above.

[0016] The present invention relates to a method, system, and electronic device for characterizing deep-level defects in gallium oxide (GaO) devices. First, isothermal deep-level voltammetry (DLTS) testing is performed on the GaO device to obtain an isothermal capacitance-test period curve. Based on this curve, the range of values ​​for the test period is determined, laying the foundation for subsequent targeted DLTS testing. This ensures that the selection of the test period is based on the actual capacitance characteristic variation of the device at a specific temperature, allowing subsequent tests to be performed within a period range that matches the device characteristics. An initial DLTS test is performed based on preset initial experimental parameters to obtain an initial DLTS spectrum, providing a preliminary scan and general outline of the device's defects, and enabling the initial capture of some obvious defect features within the device.

[0017] Then, based on the initial DLTS spectrum, the test cycle is extended within the previously determined value range, and the DLTS test is repeated to obtain the final DLTS spectrum. This progressive testing method from initial to final, as described in this invention, fully utilizes the results of the initial test to guide subsequent, more in-depth, and precise tests. It achieves a gradual characterization process of device defects from coarse to fine, effectively improving the detection capability and characterization accuracy of various defects. This results in a more complete and accurate final DLTS spectrum, providing richer information and a more reliable basis for subsequent defect analysis.

[0018] Furthermore, all defect peaks in the final DLTS spectrum are fitted to determine the defect energy level and trapping cross section for each peak. Through fitting analysis of all defect peaks, the complex signal in the final DLTS spectrum can be decomposed into individual defect features, accurately extracting the energy level and trapping cross section parameters corresponding to each defect. These parameters are core indicators for describing and characterizing the defect properties of the device, providing researchers with detailed information about the internal defect states of the device. This enables precise identification and quantitative analysis of defects in gallium oxide devices, meeting the demand for accurate defect characterization in material process optimization and device performance improvement.

[0019] In summary, this invention improves the accuracy of defect detection and characterization in gallium oxide devices through progressive testing and precise fitting. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the method for characterizing ultra-deep level defects in gallium oxide devices according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the isothermal capacitance-test cycle curve according to an embodiment of the present invention; Figure 3 When the test period of this embodiment of the invention is 2 seconds A schematic diagram of the deep-level transient spectrum of an SBD device; Figure 4 For the test periods of this invention embodiment, respectively 2s, 6s, 10s, 20s, and 1000s are used. Schematic diagram of the deep-level transient spectrum of an SBD device. Figure 5 Embodiments of the present invention A schematic diagram of the Arrhenius fitting results after DLTS of a Schottky diode; Figure 6 This is a schematic diagram of the structure of the gallium oxide device deep energy level defect characterization system according to an embodiment of the present invention. Detailed Implementation

[0021] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0022] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0023] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0024] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0025] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties. The collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation portals are provided for users to choose to authorize or refuse.

[0026] In related technologies, gallium oxide ( As a core representative of fourth-generation ultra-wide bandgap semiconductors, it has an ultra-wide bandgap of up to 4.8-4.9 eV, which gives the material an extremely high critical breakdown field strength.

[0027] Single crystals can be grown and fabricated into large-size wafers using low-cost melt methods, showing great promise for industrialization. However, the material growth and processing inevitably introduce intrinsic and extrinsic defects such as gallium vacancies, oxygen vacancies, and various impurities. These deep-level defects form carrier traps in the bandgap, leading to a series of critical performance degradation problems in devices, including increased reverse leakage current, decreased breakdown voltage, degraded conduction characteristics, and reduced reliability.

[0028] Deep-level transient spectroscopy (DLTS) has become a core method for semiconductor defect analysis due to its high sensitivity and ability to quantitatively analyze defect characteristic parameters (such as energy levels and concentrations). This technology can detect deep-level defects with extremely low concentrations by monitoring transient signals of capacitance or current, making it a key tool for diagnosing device performance and process issues.

[0029] However, traditional DLTS faces significant limitations when applied to ultra-wide bandgap semiconductors such as gallium oxide. Its fixed short pulse width testing mode, while effective for simple point defects, struggles to fully detect the widespread extended defects in gallium oxide (such as dislocations and vacancy groups). These defects exhibit continuous emission time constant distributions, meaning short pulses can only excite their shallow energy levels, resulting in weak or even masked deep energy level signals. Simultaneously, high-activation-energy, high-temperature defects cannot be effectively observed due to instrument range limitations or device leakage at conventional testing temperatures, leading to incomplete traditional DLTS spectra and the omission of a large amount of crucial defect information.

[0030] To address the above problems, this invention provides a method, system, and electronic device for characterizing ultra-deep level defects in gallium oxide devices.

[0031] Combination Figure 1 As shown, this embodiment of the invention provides a method for characterizing extremely deep level defects in gallium oxide devices, including: Isothermal DLTS testing was performed on the gallium oxide device to obtain the isothermal capacitance-test period curve, and the range of test period values ​​was determined based on the isothermal capacitance-test period curve.

[0032] Specifically, the gallium oxide device is placed on the hot and cold stage of the DLTS measurement system, ensuring a good connection between its electrodes and the system. Isothermal test conditions are then set, such as maintaining a constant temperature at a specific value, while simultaneously setting an appropriate bias voltage to ensure the device is in a suitable electrical state during the test. Isothermal DLTS testing is then performed, recording the capacitance changes at different values ​​of Tw. Finally, the appropriate range of Tw values ​​is determined based on the isothermal capacitance-Tw curve results. Identifying the Tw range with significant capacitance changes from the curve provides the subsequent Tw value range for testing, laying the foundation for effectively exciting defect signals.

[0033] Based on preset initial experimental parameters, the gallium oxide device was subjected to its first DLTS test to obtain an initial DLTS spectrum.

[0034] Specifically, the estimated experimental parameters were set, for example, the bias voltage UR was set to -5V, UP to -0.1V, the initial Tw to 2s, the temperature scan range to 399K-30K, and the cooling rate to 2K / min. The compressor and molecular pump were turned on, the temperature scan program was started to begin the test, and data was acquired in real time. Through detailed parameter settings and operations, the initial DLTS spectrum was finally obtained. This spectrum can initially show the characteristics and distribution of some defects in the gallium oxide device, providing a basis for further optimization of the test conditions.

[0035] Based on the initial DLTS spectrum, the test period is extended within the specified range, and the gallium oxide device is repeatedly subjected to DLTS testing to obtain the final DLTS spectrum.

[0036] Specifically, based on the initial DLTS spectrum, defect peaks that may not have been fully excited or captured can be found in certain high-temperature regions or specific locations. Therefore, within the range of Tw values, Tw is successively increased to 6s, 10s, 20s, 1000s, etc., and DLTS tests are repeated. As Tw increases, the peaks in the deep-level transient spectrum change accordingly, such as shifting towards lower temperatures. When Tw is increased by 10s, the previously incomplete fourth defect peak signal can be completely captured; when Tw is increased to a very large value, such as 1000s, the previously difficult-to-observe fifth high-temperature defect peak can be detected and captured, thus gradually obtaining a complete and comprehensive final DLTS spectrum, achieving a deeper and more comprehensive detection of internal defects in gallium oxide devices.

[0037] All defect peaks in the final DLTS spectrum are fitted to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.

[0038] Specifically, after obtaining the complete final DLTS spectrum, each defect peak is fitted using an analysis method such as Arrhenius. By establishing a functional relationship between the peak position and temperature, and combining it with the corresponding physical model, the key parameters such as the energy level and trapping cross section corresponding to each defect are accurately calculated.

[0039] The method for characterizing deep-level defects in gallium oxide (GaO) devices in this embodiment first performs isothermal DLTS testing on the GaO device to obtain an isothermal capacitance-test period curve, and determines the range of test period values ​​accordingly. This lays the foundation for subsequent targeted DLTS testing, ensuring that the selection of the test period is based on the actual capacitance characteristic change law of the device at a specific temperature, so that subsequent tests can be carried out within a period range that matches the device characteristics. An initial DLTS test is performed based on preset initial experimental parameters to obtain an initial DLTS spectrum, which provides a preliminary scan and general outline of the device's defects, enabling the initial capture of some obvious defect features in the device.

[0040] Then, based on the initial DLTS spectrum, the testing period is extended within the previously determined value range, and the DLTS test is repeated to obtain the final DLTS spectrum. This progressive testing method from initial to final, as described in this embodiment, fully utilizes the results of the initial test to guide subsequent, more in-depth, and precise testing. It achieves a gradual characterization process of device defects from coarse to fine, effectively improving the detection capability and characterization accuracy of various defects. This results in a more complete and accurate final DLTS spectrum, providing richer information and a more reliable basis for subsequent defect analysis.

[0041] Furthermore, all defect peaks in the final DLTS spectrum are fitted to determine the defect energy level and trapping cross section for each peak. Through fitting analysis of all defect peaks, the complex signal in the final DLTS spectrum can be decomposed into individual defect features, accurately extracting the energy level and trapping cross section parameters corresponding to each defect. These parameters are core indicators for describing and characterizing the defect properties of the device, providing researchers with detailed information about the internal defect states of the device. This enables precise identification and quantitative analysis of defects in gallium oxide devices, meeting the demand for accurate defect characterization in material process optimization and device performance improvement.

[0042] In summary, this embodiment improves the accuracy of defect detection and characterization in gallium oxide devices through progressive testing and precise fitting.

[0043] Optionally, the isothermal DLTS test of the gallium oxide device to obtain the isothermal capacitance-test period curve includes: At a preset constant test temperature, carriers are filled into the defect energy level by forward bias. Within the initial range of the test cycle, the test cycle is gradually adjusted according to preset requirements. The capacitor transient signal is monitored by reverse bias to obtain the capacitance value under different test cycles. The isothermal capacitance-test cycle curve is generated based on the capacitance value and the corresponding test period.

[0044] Specifically, the gallium oxide device is placed on a hot / cold stage and the electrodes are connected to ensure a stable connection with the DLTS measurement system. The test temperature is kept constant at a preset value, such as 300K. By applying a forward bias voltage (e.g., 0.1V), the Schottky barrier height is lowered, thereby achieving carrier filling of the defect energy level. Within the initial range of the test cycle (Tw), for example starting from 2 seconds, Tw is gradually adjusted in steps (e.g., increasing by 2 seconds each time). At each set Tw, a forward bias voltage is first applied for filling, followed by a rapid switch to a reverse bias voltage (e.g., -5V). Throughout the process, a high-precision capacitance monitor is used to monitor the transient capacitance signal in real time, and the capacitance values ​​corresponding to different Tw values ​​are recorded.

[0045] Capacitance data at different temperature ranges (Tw) were collected, and each capacitance value was paired with its corresponding Tw. Using professional plotting software, a curve was plotted with capacitance as the ordinate and the test period as the abscissa. Through curve fitting and other methods, the curve was smoothed to clearly show the capacitance variation trend with the test period, ultimately yielding a complete isothermal capacitance-test period curve.

[0046] In this optional embodiment, isothermal DLTS testing is performed on the gallium oxide device at a preset constant temperature. Carrier filling of the defect energy level is achieved using a forward bias, and the test period is gradually adjusted within an initial range. Combined with reverse bias monitoring of the transient capacitance signal, the capacitance values ​​under different test periods are obtained, generating isothermal capacitance-test period curves. This not only provides accurate data for determining a suitable test period range and optimizes test conditions, but also enhances the detection capability for extended defects and high-temperature deep-level defects.

[0047] Optionally, determining the range of values ​​for the test period based on the isothermal capacitance-test period curve includes: Based on the trend of the capacitance value changing with the test period in the isothermal capacitance-test period curve, the key range of the capacitance value is determined; The range of values ​​for the test period is determined based on the upper and lower limits of the critical interval of the capacitance value. The range of values ​​covers the time required for the expansion defect and the carrier filling.

[0048] Specifically, the isothermal capacitance-test cycle curve is analyzed to observe the trend of capacitance value change with the test cycle, identifying regions where the capacitance value changes significantly, such as areas where the capacitance value suddenly increases or decreases. These regions typically correspond to the activation or deactivation process of defects. The upper and lower limits of these regions with significant changes are determined as critical ranges for the capacitance value, such as the region between the minimum and maximum capacitance values. Based on the critical ranges for the capacitance value, the corresponding upper and lower limits for the test cycle are found. For example, if the critical range for the capacitance value corresponds to the entire test cycle from start to finish, this range is determined as the range of test cycle values. This range covers the time required for expanding defects and carrier filling, ensuring that these defects can be fully excited and detected in subsequent DLTS tests. By rationally selecting the range of test cycle values, the detection capability and characterization accuracy of deep-level defects in gallium oxide devices can be effectively improved.

[0049] In this optional embodiment, by analyzing the trend of capacitance value change with the test cycle in the isothermal capacitance-test cycle curve, the key range of capacitance value is accurately determined, and the range of test cycle values ​​is set accordingly to ensure that the time required for extended defects and carrier filling is covered. This effectively optimizes the test conditions, improves test efficiency, and enhances the detection capability for deep-level defects, especially extended defects and high-temperature defects.

[0050] Optionally, the step of performing the first DLTS test on the gallium oxide device based on preset initial experimental parameters to obtain an initial DLTS spectrum includes: Temperature is controlled according to the temperature scan range and cooling rate in the preset initial experimental parameters, and the transient signal of the capacitor is excited and monitored by applying a reverse bias voltage to the gallium oxide device. Based on the capacitance transient signal, noise reduction and spectrum conversion processing are performed to generate the initial DLTS spectrum.

[0051] Specifically, the temperature scan range and cooling rate are set according to experimental requirements. For example, the temperature scan range is set to 399K to 30K, and the cooling rate is 2K / min. The gallium oxide device is placed on a hot-cold stage, and the temperature is regulated according to the set temperature scan range and cooling rate using the stage's temperature control system. Simultaneously with temperature regulation, a reverse bias voltage (e.g., -5V) is applied to the gallium oxide device through the bias source of the DLTS measurement system. This bias voltage is used to monitor transient capacitance signals. During the test, the precise control of the bias voltage application sequence and duration ensures effective excitation and monitoring of transient capacitance signals.

[0052] The system acquires transient capacitance signals in real time to obtain raw data on capacitance changes over time. Digital signal processing (DSP) techniques are used to denoise the raw data, such as filtering algorithms to remove noise interference and improve the signal-to-noise ratio. The denoised transient capacitance signals are then converted into a DLTS (Defect-to-Treatment Synchronization) spectrum. Analysis software then converts the capacitance changes into a spectrum related to defects, thereby generating an initial DLTS spectrum.

[0053] In this optional embodiment, by controlling the temperature according to preset initial experimental parameters and applying forward and reverse bias voltages, defects in the gallium oxide device can be effectively excited, generating a clear transient capacitance signal. Precise temperature scanning and reasonable bias voltage settings ensure the stability and repeatability of the test conditions. Subsequent noise reduction processing effectively improves signal quality, filtering out interference factors during the test process. Spectrum conversion processing accurately converts the original capacitance signal into a physically meaningful DLTS spectrum, enabling the initial DLTS spectrum to more accurately reflect the preliminary characteristics of internal defects in the device, providing a reliable foundation for subsequent optimization of test parameters and complete defect detection.

[0054] Optionally, the step of extending the test period and repeating the DLTS test on the gallium oxide device within the value range based on the initial DLTS spectrum to obtain the final DLTS spectrum includes: The initial DLTS spectrum is analyzed to determine the integrity of the defect peaks in the initial DLTS spectrum; Based on the integrity of the defect peak, the test period is extended within the range of the value, and the gallium oxide device is repeatedly subjected to DLTS test to obtain the intermediate DLTS spectrum after each DLTS test. The changes in defect peaks in the intermediate DLTS spectrum and the initial DLTS spectrum are compared and analyzed until all the defect peaks are obtained, and the spectrum containing all the defect peaks is taken as the final DLTS spectrum.

[0055] Specifically, the initial DLTS spectrum is opened using specialized analysis software. Each defect peak is observed, and its shape, height, width, and position are examined to determine its completeness. For example, if a peak shows significant truncation or absence within the temperature scan range, or if its shape is incomplete (e.g., the leading or trailing edge is missing), it indicates that the defect peak is incomplete. Simultaneously, the shape of theoretical defect peaks or known standard defect peaks is compared to further confirm the completeness of the defect peaks in the initial spectrum.

[0056] Based on the analysis of the initial DLTS spectrum, if incomplete defect peaks are found, the test period (Tw) is gradually extended within the previously determined range. For example, if the initial Tw is 2s, it can be extended sequentially to 6s, 10s, 20s, 1000s, etc. After each change in Tw, the DLTS test is repeated on the gallium oxide device, and the intermediate DLTS spectrum after each test is recorded. In each test, ensure that other experimental parameters (such as bias voltage, temperature scan range, etc.) remain constant, and only adjust Tw to ensure consistency of test conditions.

[0057] The intermediate DLTS spectra obtained from each test are compared and analyzed with the initial DLTS spectra. The focus is on changes in the number, shape, and position of defect peaks. For example, as the time interval (Tw) increases, observe whether previously incomplete defect peaks gradually become complete, and whether new defect peaks appear. When all defect peaks are found to be complete in the intermediate spectra, and the defect peaks in the spectra do not change significantly after several consecutive increases in Tw, it can be considered that a complete spectra containing all defect peaks has been obtained, and this spectra is used as the final DLTS spectra.

[0058] In this optional embodiment, the integrity of defect peaks is accurately identified by analyzing the initial DLTS spectrum. Based on this, the testing cycle is extended within a preset range for repeated testing, gradually refining the defect peak information. As the testing cycle extends, the initially incomplete defect peaks are completed, and the masked high-temperature defect peaks gradually become visible, until a complete spectrum containing all defect peaks is obtained. This process not only optimizes the testing parameters but also significantly improves the detection capability and characterization accuracy of deep-level defects in gallium oxide devices, providing high-quality data support for subsequent precise analysis of defect characteristics.

[0059] Optionally, extending the test cycle within the value range based on the integrity of the defect peak includes: The test cycle is extended within the range of values ​​by extending the time window for defect filling and / or emission.

[0060] Specifically, the test period is extended by increasing the time window for defect filling and carrier emission. In this embodiment of the invention, the defect filling and carrier emission processes in DLTS testing require a certain time window to complete. If the test period (Tw) is too short, some deep-level defects, especially those with slow capture or emission dynamics, may not be able to complete the filling or emission process in a short time, resulting in incomplete or missed signals in the spectrum.

[0061] In a preferred embodiment of the invention, the value of Tw is gradually increased to extend this time window. For example, starting from an initial Tw value (e.g., 2 seconds), it is gradually extended to a larger value (e.g., 6 seconds, 10 seconds, 20 seconds, or even 1000 seconds), thereby providing more time for the defect to complete the filling and emission process, so that defect signals that cannot be effectively detected at shorter Tw values ​​can be captured.

[0062] For example, in specific operations, Tw is adjusted according to the range determined by the isothermal capacitance-test cycle curve. By gradually increasing Tw in each test and analyzing the spectrum after each test, it can be observed that as Tw extends, the originally incomplete defect peaks gradually become complete, and new defect peaks may appear. This process needs to be repeated until all defect peaks present a complete form in the spectrum, thereby ensuring that the final DLTS spectrum can comprehensively and accurately reflect the deep-level defect information in the gallium oxide device.

[0063] In this optional embodiment, by extending the test period (Tw), a more ample filling and carrier emission time window is provided for the defects, thereby effectively enhancing the detection capability of deep-level defects in gallium oxide devices. This not only allows the defect peaks that were originally incomplete in short-period testing to be fully presented, but also allows the masked high-temperature defect peaks to gradually emerge, thus optimizing the test accuracy and ensuring that the final DLTS spectrum can comprehensively and accurately reflect the information of all defects inside the device.

[0064] Optionally, the step of extending the test cycle within the value range and repeatedly performing DLTS testing on the gallium oxide device based on the defect peak integrity to obtain an intermediate DLTS spectrum after each DLTS test includes: Based on the integrity of the defect peaks, the defect peaks in the initial DLTS spectrum are determined; Within the range of values ​​for the test cycle, the test cycle is extended in a gradually increasing manner, while keeping the reverse bias voltage, temperature scan range, and cooling rate in the preset initial experimental parameters unchanged. The DLTS test is repeated sequentially for each extended test cycle, and the capacitance transient signal of each DLTS test is continuously collected. Based on the capacitor transient signal, the intermediate DLTS spectrum after each DLTS test is generated.

[0065] Specifically, by analyzing the initial DLTS spectrum, defect peaks are identified. Within a preset range of test cycles, the test cycle is gradually increased, for example, from an initial 2 seconds to 6 seconds, 10 seconds, 20 seconds, and even 1000 seconds. During each adjustment of the test cycle, other experimental parameters such as reverse bias (e.g., -5V), temperature scan range (e.g., 399K to 30K), and cooling rate (e.g., 2K / min) remain constant. The gallium oxide device is subjected to repeated DLTS tests for each extended test cycle, with continuous acquisition of transient capacitance signals. Finally, the acquired transient capacitance signals are processed to generate intermediate DLTS spectra after each test for further analysis and comparison.

[0066] In this optional embodiment, by gradually extending the test period and repeating the DLTS test, the detection capability of deep-level defects in gallium oxide devices can be effectively enhanced. Specifically, this embodiment allows observation of the defect filling and emission process within a longer time window, enabling the manifestation of deep-level defect signals that might be ignored under shorter test periods. This not only improves the detection sensitivity for high-temperature defects but also optimizes the test conditions, ensuring the accuracy of the test results. By keeping other experimental parameters constant, the consistency of the test conditions is also guaranteed, ensuring that the acquired transient capacitance signals can accurately reflect the impact of test period changes on defect detection, thereby providing a guarantee for generating reliable intermediate DLTS spectra.

[0067] Optionally, fitting all defect peaks in the final DLTS spectrum to determine the defect energy level and trapping cross section of each defect peak in the final DLTS spectrum includes: The final DLTS spectrum is extracted to obtain the feature parameters of all the defect peaks in the final DLTS spectrum. The feature parameters include the peak position, peak shape profile and peak intensity data of the defect peaks. Substitute the peak position, peak shape profile, and peak intensity data of each defect peak into the fitting model, perform data fitting calculation, and obtain the energy difference and carrier capture probability parameters corresponding to each defect peak; The fitting model is established using the Arrhenius fitting method based on the correlation between temperature and carrier emission time constant. The energy difference is used as the defect energy level of the defect peak, and the carrier capture probability parameter is used as the capture cross section of the defect peak.

[0068] Specifically, the final DLTS spectrum is imported into professional data analysis software, such as Origin or Matlab. The software's peak detection function is used to identify each defect peak in the spectrum. The peak position of each defect peak is recorded, including the corresponding temperature or frequency, peak shape profile (such as peak width and symmetry), and peak intensity data (such as peak height or area). These characteristic parameters describe the properties of each defect peak, providing the basic data for subsequent fitting calculations.

[0069] The characteristic parameters of each extracted defect peak are substituted into a fitting model based on the Arrhenius equation. The Arrhenius fitting model, by analyzing the relationship between temperature and the carrier emission time constant, can calculate the energy difference corresponding to each defect peak, i.e., the defect energy level and the carrier capture probability parameter, i.e., the capture cross section. During the fitting process, the model parameters are adjusted to achieve the best match between the theoretical curve and the defect peaks in the actual spectrum, thereby obtaining accurate defect energy level and capture cross section values.

[0070] The energy difference calculated by the fitted model directly corresponds to the defect energy level, i.e., the defect's position within the bandgap. The carrier trapping probability parameter reflects the defect's ability to trap carriers, i.e., the trapping cross-section. These two parameters are important physical quantities describing defect characteristics and can provide crucial information for defect identification, quantitative analysis, and performance optimization of gallium oxide devices.

[0071] In this optional embodiment, a systematic fitting of the final DLTS spectrum enables precise analysis of each defect peak, accurately determining the defect energy level and trapping cross section. The application of the Arrhenius fitting model, based on the correlation between temperature and carrier emission time constant, provides highly accurate quantitative analysis results.

[0072] In a preferred embodiment of the present invention, this experiment employs The SBD device was characterized using a deep-level transient spectroscopy (DLTS) system. First, isothermal DLTS testing was performed to obtain the isothermal capacitance-Tw test curves, as shown below. Figure 2 As shown. Within a suitable range, we first tried setting the Tw value to 2s, and the resulting deep-level transient spectrum is shown below. Figure 3 As shown, when Tw is set to 2s, four peaks are detected, corresponding to four defects, but the fourth peak is not completely detected within the temperature scanning range.

[0073] To capture the complete peak, the test parameters needed to be optimized. Therefore, Tw was adjusted and increased to 6s, 10s, and 20s before re-performing the DLTS test. The test results are as follows: Figure 4 As shown, it can be observed that as Tw increases, the peak in the transient spectrum shifts towards the lower temperature. When Tw increases to 10s, the fourth peak signal has been completely captured within the temperature scanning range.

[0074] When Tw was increased to 20 s, the results showed that a high-temperature peak corresponding to the fifth defect might exist. Therefore, Tw was further increased to 1000 s to try to capture the high-temperature peak. The experimental results are as follows. Figure 4 As shown in the figure. The results show that when Tw increases to a very large 1000s, the fourth peak shifts to around 340K, and the high-temperature peak corresponding to the fifth defect is detected around 380K.

[0075] The DLTS experiment yielded signals with five peaks. Arrhenius fitting was then performed on each peak to obtain the following results: Figure 5 As shown in the figure, the fitted defect energy levels and defect concentrations are labeled within the graph. From left to right, the defect energy levels gradually decrease; larger energy levels correspond to peaks at higher temperatures. Specifically, the fifth high-temperature peak corresponds to a defect energy level of 1.328 eV and a concentration of [missing value]. .

[0076] By extending the DLTS measurement time window, the defect filling dynamics were effectively controlled, successfully enhancing the ability to measure defects. Detection capability of extended defects and high-temperature deep-level defects in Schottky diodes.

[0077] In this embodiment, by gradually extending Tw from 2s to 1000s, the previously difficult-to-observe fifth high-temperature defect peak was detected and captured near 380K. The energy level of this defect was determined to be Ec-1.328eV, with a concentration of [missing information]. As Tw increases, the DLTS peak shifts towards lower temperatures. When Tw increases to 10 s, the previously incomplete fourth defect peak signal is fully captured. The experiment yielded five defect signal peaks, and their energy levels and concentrations were determined through Arrhenius fitting, overcoming the characterization blind zone of traditional short-pulse DLTS spectra in the high-temperature region of ultra-wide bandgap semiconductors. This embodiment, by changing Tw to regulate defect carrier emission, provides a new and more powerful characterization platform to address the technical challenge of the insensitivity of traditional DLTS for detecting extended defects and defects in high-temperature regions.

[0078] Combination Figure 6 As shown, an embodiment of the present invention provides a gallium oxide device deep-level defect characterization system, comprising: The testing unit is used to perform isothermal DLTS testing on the gallium oxide device to obtain an isothermal capacitance-test period curve, and to determine the range of test period values ​​based on the isothermal capacitance-test period curve; based on preset initial experimental parameters, the gallium oxide device is subjected to the first DLTS test to obtain an initial DLTS spectrum; based on the initial DLTS spectrum, the test period is extended within the range of values, and the DLTS test on the gallium oxide device is repeated to obtain the final DLTS spectrum; A fitting unit is used to fit all the defect peaks in the final DLTS spectrum to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.

[0079] The gallium oxide device deep level defect characterization system of the present invention has the same advantages over the prior art as the above-mentioned gallium oxide device deep level defect characterization method over the prior art, and will not be repeated here.

[0080] An electronic device according to an embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the gallium oxide device deep energy level defect characterization method as described above.

[0081] The computer device of the present invention has the same advantages over the prior art as the above-mentioned method for characterizing deep energy level defects in gallium oxide devices, and will not be repeated here.

[0082] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for characterizing extremely deep level defects in gallium oxide devices, characterized in that, include: Isothermal DLTS testing was performed on gallium oxide devices to obtain isothermal capacitance-test period curves, and the range of test period values ​​was determined based on the isothermal capacitance-test period curves. Based on preset initial experimental parameters, the gallium oxide device was subjected to its first DLTS test to obtain an initial DLTS spectrum; Based on the initial DLTS spectrum, the test period is extended within the range of the values, and the DLTS test is repeated on the gallium oxide device to obtain the final DLTS spectrum. All defect peaks in the final DLTS spectrum are fitted to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.

2. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 1, characterized in that, The isothermal DLTS test performed on the gallium oxide device to obtain the isothermal capacitance-test period curve includes: At a preset constant test temperature, carriers are filled into the defect energy level by forward bias. Within the initial range of the test cycle, the test cycle is gradually adjusted according to preset requirements. The capacitor transient signal is monitored by reverse bias to obtain the capacitance value under different test cycles. The isothermal capacitance-test cycle curve is generated based on the capacitance value and the corresponding test period.

3. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 2, characterized in that, The step of determining the range of values ​​for the test period based on the isothermal capacitance-test period curve includes: Based on the trend of the capacitance value changing with the test period in the isothermal capacitance-test period curve, the key range of the capacitance value is determined; The range of values ​​for the test period is determined based on the upper and lower limits of the critical interval of the capacitance value. The range of values ​​covers the time required for the expansion defect and the carrier filling.

4. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 1, characterized in that, The initial DLTS test of the gallium oxide device, based on preset initial experimental parameters, yields an initial DLTS spectrum, including: Temperature is controlled according to the temperature scan range and cooling rate in the preset initial experimental parameters, and the transient signal of the capacitor is excited and monitored by applying a reverse bias voltage to the gallium oxide device. Based on the capacitance transient signal, noise reduction and spectrum conversion processing are performed to generate the initial DLTS spectrum.

5. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 1, characterized in that, The step of extending the test period within the value range and repeatedly performing DLTS tests on the gallium oxide device based on the initial DLTS spectrum to obtain the final DLTS spectrum includes: The initial DLTS spectrum is analyzed to determine the integrity of the defect peaks in the initial DLTS spectrum; Based on the integrity of the defect peak, the test period is extended within the range of the value, and the gallium oxide device is repeatedly subjected to DLTS test to obtain the intermediate DLTS spectrum after each DLTS test. The changes in defect peaks in the intermediate DLTS spectrum and the initial DLTS spectrum are compared and analyzed until all the defect peaks are obtained, and the spectrum containing all the defect peaks is taken as the final DLTS spectrum.

6. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 5, characterized in that, Extending the test cycle within the range of values ​​based on the integrity of the defect peak includes: The test cycle is extended within the range of values ​​by extending the time window for defect filling and / or emission.

7. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 5, characterized in that, The step of extending the test cycle within the range of the defect peak integrity and repeatedly performing DLTS testing on the gallium oxide device to obtain an intermediate DLTS spectrum after each DLTS test includes: Based on the integrity of the defect peaks, the defect peaks in the initial DLTS spectrum are determined; Within the range of values ​​for the test cycle, the test cycle is extended in a gradually increasing manner, while keeping the reverse bias voltage, temperature scan range, and cooling rate in the preset initial experimental parameters unchanged. The DLTS test is repeated sequentially for each extended test cycle, and the capacitance transient signal of each DLTS test is continuously collected. Based on the capacitor transient signal, the intermediate DLTS spectrum after each DLTS test is generated.

8. The method for characterizing ultra-deep level defects in gallium oxide devices according to claim 1, characterized in that, The process of fitting all defect peaks in the final DLTS spectrum to determine the defect energy level and trapping cross section of each defect peak in the final DLTS spectrum includes: The final DLTS spectrum is extracted to obtain the feature parameters of all the defect peaks in the final DLTS spectrum. The feature parameters include the peak position, peak shape profile and peak intensity data of the defect peaks. Substitute the peak position, peak shape profile, and peak intensity data of each defect peak into the fitting model, perform data fitting calculation, and obtain the energy difference and carrier capture probability parameters corresponding to each defect peak; The fitting model is established using the Arrhenius fitting method based on the correlation between temperature and carrier emission time constant. The energy difference is used as the defect energy level of the defect peak, and the carrier capture probability parameter is used as the capture cross section of the defect peak.

9. A system for characterizing deep energy level defects in gallium oxide devices, characterized in that, include: The testing unit is used to perform isothermal DLTS testing on the gallium oxide device to obtain an isothermal capacitance-test period curve, and to determine the range of test period values ​​based on the isothermal capacitance-test period curve; based on preset initial experimental parameters, the gallium oxide device is subjected to the first DLTS test to obtain an initial DLTS spectrum; based on the initial DLTS spectrum, the test period is extended within the range of values, and the DLTS test on the gallium oxide device is repeated to obtain the final DLTS spectrum; A fitting unit is used to fit all the defect peaks in the final DLTS spectrum to determine the defect energy level and capture cross section of each defect peak in the final DLTS spectrum.

10. An electronic device comprising 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, it implements the steps of the method for characterizing ultra-deep level defects in gallium oxide devices according to any one of claims 1 to 8.

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