Power device testing device and power device testing method

Abstract

The invention relates to the technical field of semiconductor devices, in particular to a power device testing device and a power device testing method.The power device testing device comprises a focused ion beam-scanning electron microscope module, a focusing ion beam unit of the focused ion beam-scanning electron microscope module carries out milling operation on a power device to be tested; a scanning electron microscope unit performs scanning imaging on the surface of a to-be-tested power device subjected to single milling so as to obtain a target image; positioning an electrical test point of the to-be-tested power device in the target image to obtain coordinate information of the electrical test point; the control module is used for generating a probe control signal based on the coordinate information and sending the probe control signal to the probe module; the probe module moves a probe of the probe module to a position corresponding to the coordinate information based on the probe control signal so as to perform electrical parameter detection on the electrical test point to obtain a target electrical parameter and feed the target electrical parameter back to the control module; according to the device, the to-be-tested power device can be prevented from being transferred in the testing process, and positioning errors caused by transferring are eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a power device testing device and a power device testing method. Background Art

[0002] In the field of semiconductor device technology, it is usually necessary to analyze the microstructure of the device through tomography, and to analyze the electrical performance of the device through electrical testing. At present, tomography and electrical testing are usually carried out in steps, that is, the sample is first milled and imaged by a focused ion beam-scanning electron microscope (FIB-SEM) to obtain the microstructure information inside the device, and then the sample is transferred to a probe station for electrical testing to measure its electrical properties.

[0003] However, the above method has certain defects, as follows: 1. During the transfer process between the FIB-SEM and the probe station, positioning deviations (usually greater than 5μm (micrometers)) are prone to occur, resulting in the inability to accurately align the probe with the target area during electrical testing, thereby affecting the accuracy and reliability of the test results; 2. Since the sample (milled power device) is exposed to the air during the transfer process, it is easy to cause surface contamination or oxidation of the sample, which has a certain impact on the accuracy of the electrical test; 3. The complexity and time cost of the test are increased, and the overall efficiency is reduced. Summary of the invention

[0004] The present invention provides a power device testing device and a power device testing method, so as to solve the problem in the prior art that positioning deviation is easy to occur during the transfer process of samples between FIB-SEM and probe station, resulting in the probe being unable to accurately align with the target area during electrical testing, thereby affecting the accuracy and reliability of the test results.

[0005] The present invention provides a power device testing device, comprising:

[0006] A focused ion beam-scanning electron microscope module, wherein the focused ion beam unit performs a milling operation on the power device to be tested; the scanning electron microscope unit scans and images the surface of the power device to be tested that has completed a single milling operation to obtain a target image; the electrical test points of the power device to be tested in the target image are located to obtain the coordinate information of the electrical test points, and the coordinate information is fed back to the control module;

[0007] A control module, which generates a probe control signal based on the coordinate information and sends the signal to the probe module;

[0008] The probe module moves its probe to a position corresponding to the coordinate information based on the probe control signal, so as to detect electrical parameters of the electrical test point, obtain target electrical parameters and feed them back to the control module.

[0009] In one embodiment of the present invention, the control module is further used to obtain test requirements, and the test requirements include target milling times and single milling depth;

[0010] Based on the milling times and the single milling depth, a milling signal is generated, wherein the milling signal is used to instruct the focused ion beam unit to complete the milling of the power device to be tested one by one at preset time intervals until the accumulated milling times reaches the target milling times.

[0011] In one embodiment of the present invention, the test requirement further includes a to-be-tested area, the to-be-tested area is a preset area where the electrical test points are located, and the to-be-tested area corresponds to the electrical test points one by one;

[0012] The control module is further used for, when there are multiple areas to be tested in the test requirement, performing electrical test path planning based on the position distribution of the multiple areas to be tested in the power device to be tested, so as to obtain an electrical test path, wherein the electrical test path specifies a sequential test order of the multiple areas to be tested;

[0013] If the coordinate information of the plurality of electrical test points is received, the probe control signal is generated based on the electrical test path and the coordinate information to instruct the probe module to complete the electrical parameter detection of the plurality of electrical test points in the sequential test order.

[0014] In one embodiment of the present invention, if there are multiple probes in the probe module and multiple electrical test points, the probe module assigns tasks to each probe based on the number of probes, the electrical test path in the probe control signal, and the coordinate information to determine the detection path of each probe; based on the detection path of each probe, each probe is independently controlled to complete the electrical parameter detection of the multiple electrical test points.

[0015] In one embodiment of the present invention, the power device testing device further includes:

[0016] The local gas injection module is used to purge the milling residues at and around the electrical test point by means of gas injection before the probe module performs electrical parameter detection.

[0017] In one embodiment of the present invention, the local gas injection module is a vapor deposition device, which releases a gaseous precursor to the electrical test point before the probe module performs electrical parameter detection to complete the purging of milling residues at the electrical test point and its surroundings, and to form a deposited film on the surface of the electrical test point;

[0018] When the probe performs electrical parameter detection on the electrical test point, the probe makes electrical contact with the deposited film on the surface of the electrical test point to complete the electrical parameter detection.

[0019] In one embodiment of the present invention, the vapor deposition equipment performs vapor deposition on the electrical test point upon receiving a vapor deposition signal sent by the control module. The vapor deposition signal is generated and sent by the control module before sending the probe control signal. The sending time interval between the vapor deposition signal and the probe control signal is a preset interval. The vapor deposition signal is generated based on the coordinate signal.

[0020] In one embodiment of the present invention, the control module further receives the target image sent by the scanning electron microscope unit; and constructs a three-dimensional structural model of the power device to be tested based on a plurality of the target images;

[0021] Sorting the target electrical parameters collected multiple times at any electrical test point in time sequence to obtain a change trend of the electrical parameters; determining whether there is an abnormality at the current electrical test point based on the change trend of the electrical parameters;

[0022] If there is an abnormality in the electrical test point, an abnormality mark is made at the location of the electrical test point in the three-dimensional structural model.

[0023] In one embodiment of the present invention, the control module further obtains a change amount between target electrical parameters detected by two adjacent electrical parameter detections of the same electrical test point;

[0024] If the change amount is greater than or equal to a preset change threshold, a milling pause signal is sent to the focused ion beam unit to instruct the focused ion beam unit to pause milling, and an imaging signal is sent to the scanning electron microscope unit to instruct the scanning electron microscope unit to scan and image the current electrical test point, obtain a structural image and send it to the control module;

[0025] The control module determines the defect type of the current electrical test point by performing defect recognition on the structural image;

[0026] The focused ion beam-scanning electron microscope module and the probe module are integrated in the same vacuum chamber, and the vacuum chamber has a built-in probe station and a sample carrying platform. The probe station and the sample carrying platform are located on the same platform, and the probe station and the sample carrying platform completely or partially overlap, and the power device to be tested is located at the overlapping part of the probe station and the sample carrying platform.

[0027] The present invention also provides a power device testing method based on the power device testing apparatus as described in any one of the above items, comprising:

[0028] Controlling the focused ion beam unit to perform a milling operation on the power device to be tested;

[0029] Controlling the scanning electron microscope unit to scan and image the surface of the power device to be tested that has completed a single milling operation to obtain a target image; locating the electrical test point of the power device to be tested in the target image to obtain coordinate information of the electrical test point;

[0030] Based on the coordinate information, a probe control signal is generated and sent to the probe module to instruct the probe module to move its probe to a position corresponding to the coordinate information based on the probe control signal, so as to perform electrical parameter detection on the electrical test point and obtain target electrical parameters.

[0031] Beneficial effects of the present invention: The power device testing device and the power device testing method provided by the present invention are provided with a focused ion beam-scanning electron microscope module, wherein the focused ion beam unit performs milling operation on the power device to be tested; the scanning electron microscope unit scans and images the surface of the power device to be tested that has completed a single milling operation to obtain a target image; the electrical test point of the power device to be tested in the target image is positioned to obtain the coordinate information of the electrical test point, and the coordinate information is fed back to the control module; the control module generates a probe control signal based on the coordinate information and sends it to the probe module; the probe module moves its probe to the position corresponding to the coordinate information based on the probe control signal to perform electrical parameter detection on the electrical test point, obtain the target electrical parameters and feed back to the control module. Through the above-mentioned setting, it is possible to avoid transferring the power device to be tested after the milling and imaging of the power device to be tested is completed, and the probe detection can be performed directly. In addition, by obtaining the coordinate information of the electrical test point and controlling the probe based on the coordinate information, the accuracy of the electrical parameter detection can be effectively improved, and the occurrence of detection position offset and the like can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of a power device testing device provided by an embodiment of the present invention;

[0033] Figure 2 An exemplary block diagram of electrical test point positioning and thin film deposition provided in accordance with an embodiment of the present invention;

[0034] Figure 3 An example diagram of a three-dimensional structural model provided in one embodiment of the present invention;

[0035] Figure 4 A schematic diagram of a flow chart of a power device testing method provided by an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0038] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0039] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0040] Combine the following Figures 1 to 5 , the power device testing device and the power device testing method provided by the present invention are explained.

[0041] See also Figure 1 , Figure 1 A schematic diagram of the structure of a power device testing device provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the device comprises:

[0042] A focused ion beam-scanning electron microscope module 110, wherein a focused ion beam unit (FIB) thereof performs a milling operation on the power device to be tested; a scanning electron microscope unit (SEM) thereof performs scanning imaging on the surface of the power device to be tested that has completed a single milling operation to obtain a target image; an electrical test point of the power device to be tested in the target image is located to obtain coordinate information of the electrical test point, and the coordinate information is fed back to the control module 120;

[0043] A control module 120 generates a probe control signal based on the coordinate information and sends the signal to the probe module 130;

[0044] The probe module 130 moves its probe to a position corresponding to the coordinate information based on the probe control signal, so as to detect electrical parameters of the electrical test point, obtain target electrical parameters and feed them back to the control module 120 .

[0045] It should be noted that, after completing a single milling and imaging of the power device to be tested, the power device testing device in the above embodiment does not need to move the milled power device to be tested, that is, it is not necessary to move the milled power device to be tested to the probe station for probe detection, but by positioning the electrical test point and controlling the probe module 130, the electrical parameter detection of the electrical test point is realized. In this way, the accuracy of electrical parameter detection of the electrical test point can be effectively improved, and the probe positioning deviation caused by the movement of the sample (the power device to be tested after milling) can be effectively avoided, that is, the probe fails to accurately locate or contact the location of the electrical test point, resulting in electrical parameter detection deviation.

[0046] It should also be noted that the electrical test point can be any structure in the power device to be tested. For example, assuming that the current power device to be tested is a GaN HEMT (GaN High Electron Mobility Transistor), its electrical test point can be its gate or source contact hole.

[0047] It should be mentioned that the target electrical parameters in the above embodiments may be parameters such as leakage current and gate capacitance of the power device to be tested, which may be set according to actual needs and will not be described in detail here.

[0048] In addition, the control module 120 is used to coordinate the execution timing of the milling of the focused ion beam unit, the scanning imaging of the scanning electron microscope unit, and the electrical parameter detection of the probe module 130.

[0049] In some embodiments, the control module 120 is further used to obtain test requirements, which include target milling times and single milling depth;

[0050] Based on the number of milling times and the single milling depth, a milling signal is generated, and the milling signal is used to instruct the focused ion beam unit to complete the milling of the power device to be tested one by one according to a preset time interval, and the depth of each milling is the single milling depth, until the cumulative number of milling times reaches the target milling number.

[0051] It should be noted that the number of milling times can be set according to actual needs, such as 3 times, 4 times, etc. The single milling depth can also be set according to actual needs, such as any value in 10-100nm (nanometers), etc. Through the above settings, multiple milling of the power device to be tested can be achieved, and the whole process is automated with strong controllability. In addition, by performing the above-mentioned multiple milling, it can help to perform statistical analysis on the target electrical parameters detected after each milling, so as to identify whether there is an abnormality in the electrical test point.

[0052] It should be mentioned that the ion beam energy of the focused ion beam unit may be 30 kV (kilovolt), etc., and the beam current may be 1 pA (picoampere) to 50 nA (nanoampere), etc. The resolution of the scanning electron microscope unit may be less than or equal to 1 nm (nanometer), etc.

[0053] In some embodiments, the test requirement further includes a to-be-tested area, the to-be-tested area is a preset area where the electrical test point is located, and the to-be-tested area corresponds to the electrical test point one by one; each electrical test point corresponds to a different to-be-tested area;

[0054] The control module 120 is further configured to plan an electrical test path based on the position distribution of the plurality of regions to be tested in the power device to be tested, so as to obtain an electrical test path when there are multiple regions to be tested in the test requirement, wherein the electrical test path specifies a sequential test order of the plurality of regions to be tested;

[0055] If the coordinate information of the plurality of electrical test points is received, the probe control signal is generated based on the electrical test path and the coordinate information to instruct the probe module 130 to complete the electrical parameter detection of the plurality of electrical test points in the sequential test order.

[0056] It should be noted that the position distribution of multiple areas to be tested in the power device to be tested can be preset. According to the position distribution of multiple electrical test points in the power device to be tested, the shortest path planning can be performed to obtain the shortest electrical test path, which helps to improve the efficiency of subsequent electrical parameter testing. It can be understood that before the power device to be tested is tested, the position distribution information of each area to be tested can be obtained according to its product information (the position distribution information refers to the coordinate information of each area to be tested in a preset first coordinate system, and the first coordinate system is a two-dimensional coordinate system constructed based on the power product to be tested). According to its position distribution information, the shortest electrical test path can be planned, so that the electrical parameters of the electrical test points in the multiple areas to be tested can be tested based on the electrical test path. During the test, the power device to be tested is placed on the sample carrying platform. Therefore, in order to obtain accurate positioning of each electrical test point and to improve the control accuracy of the probe, the above embodiment recognizes the target image to achieve accurate positioning of each electrical test point in the target image, and obtains the coordinate information of each electrical test point (the coordinate information is the coordinate information of each electrical test point in a preset second coordinate system, and the second coordinate system is a three-dimensional coordinate system constructed inside the power device test device). Then, based on the coordinate information of each electrical test point, a probe control signal is generated to control the probe.

[0057] In some embodiments, if there are multiple probes in the probe module 130 and multiple electrical test points, the probe module 130 assigns tasks to each probe based on the number of probes, the electrical test path in the probe control signal, and the coordinate information to determine the detection path of each probe; based on the detection path of each probe, each probe is independently controlled to complete the electrical parameter detection of the multiple electrical test points.

[0058] It can be understood that by assigning tasks to each probe based on the number of probes in the probe module 130, the electrical test path in the probe control signal, and the coordinate information, it can help improve the efficiency of probe detection. For example: Assuming that there are 4 probes in the probe module 130, and the power device to be tested has 4 electrical test points, a one-to-one correspondence between the 4 probes and the 4 electrical test points can be established, so as to obtain a detection path between the probe and the corresponding electrical test point, and then independently control each probe based on the detection path. Assume that there are 4 probes in the probe module 130, namely probe 1, probe 2, probe 3, and probe 4, and the power device to be tested has 6 electrical test points, namely test point 1, test point 2, test point 3, test point 4, test point 5, and test point 6. Then, a one-to-one correspondence can be established between the four probes and the four electrical test points that are closer to the probe module 130 (here, it is assumed that test point 1, test point 2, test point 3, and test point 4 are closer to the probe module 130), so as to determine the first electrical test point that each of the four probes needs to detect. Next, the distances from test point 5 to test point 1, test point 2, test point 3, and test point 4 are obtained, and the test point with the closest distance is taken as an adjacent test point. The probe corresponding to the adjacent test point is determined as the probe corresponding to test point 5. On this basis, assuming that the distance between test point 5 and test point 4 is the closest, and the probe corresponding to test point 4 is probe 4, then probe 4 continues to move to test point 5 after completing the electrical parameter detection of test point 4, so as to perform electrical parameter detection on test point 5. Similarly, test point 6 is assumed to be closest to test point 3, and the probe corresponding to test point 3 is probe 3, then probe 3 continues to move to test point 6 after completing the electrical parameter detection of test point 3, so as to complete the electrical parameter detection of test point 6.

[0059] It should be noted that the probe module 130 in the above embodiment may include a plurality of microprobes, each of which is connected to a corresponding mechanical arm, and the control of the microprobe is achieved by controlling the mechanical arm. The positioning accuracy of the microprobe may be ±0.1 μm (micrometer), etc., and the radius of curvature of the tip may be less than or equal to 50 nm (nanometer), etc. The mechanical arm may be driven by a piezoelectric ceramic drive or the like. The microprobe may be a probe with multiple degrees of freedom.

[0060] In some embodiments, if the number of probes in the probe module 130 is one and there are multiple electrical test points, the probe module 130 controls its probe to move to the position corresponding to the coordinate information of the corresponding electrical test point in the order of testing in the electrical test path based on the electrical test path and coordinate information in the probe control signal until the electrical parameter detection of all electrical test points is completed.

[0061] In some embodiments, the power device testing device further includes:

[0062] The local gas injection module 140 is used to purge the milling residues at and around the electrical test point by means of gas injection before the probe module 130 performs electrical parameter detection.

[0063] It is understandable that in order to prevent the milling residues from contaminating the electrical test points, the above embodiment provides a local gas injection module 140 to purge the electrical test points and the milling residues around them by gas injection before the electrical parameter detection. In this way, it is helpful to improve the accuracy of electrical parameter detection of the electrical test points.

[0064] In some embodiments, the local gas injection module 140 is a vapor deposition device, which releases a gaseous precursor to the electrical test point before the probe module 130 performs electrical parameter detection to complete the purging of milling residues at and around the electrical test point, and to form a deposited film on the surface of the electrical test point;

[0065] When the probe performs electrical parameter detection on the electrical test point, the probe makes electrical contact with the deposited film on the surface of the electrical test point to complete the electrical parameter detection.

[0066] It should be noted that the gaseous precursors are gaseous reactants used in the vapor deposition (CVD) process. They form a solid deposited film on the substrate surface, i.e., the surface of the electrical test points, through chemical reactions. While achieving the purging of milling residues, it also protects the electrical test points, avoids damage to the electrical test points during the electrical parameter detection process, and achieves non-destructive contact.

[0067] In some embodiments, the vapor deposition device performs vapor deposition on the electrical test point upon receiving a vapor deposition signal sent by the control module 120. The vapor deposition signal is generated and sent by the control module 120 before sending the probe control signal. The time interval between sending the vapor deposition signal and the probe control signal is a preset interval. The vapor deposition signal is generated based on the coordinate signal.

[0068] It can be understood that before the control module 120 sends the probe control signal to the probe module 130, it first generates a vapor deposition signal based on the coordinate information of the electrical test point sent by the scanning electron microscope unit and sends it to the vapor deposition device. The vapor deposition device performs local vapor deposition on the electrical test point based on the coordinate information in the vapor deposition signal. If there are multiple electrical test points, the vapor deposition device performs local vapor deposition on the multiple electrical test points one by one according to the coordinate information of the multiple electrical test points in the vapor deposition signal and the vapor deposition route (specifying the order of vapor deposition on the multiple electrical test points). The preset interval in the above embodiment can be the time required to complete the vapor deposition of all electrical test points. In the above manner, the control module 120 can achieve coordinated control of the vapor deposition equipment and the probe module 130, ensure that the vapor deposition and electrical parameter detection are carried out in an orderly manner, and ensure the efficiency of the vapor deposition and electrical parameter detection.

[0069] Figure 2 For an exemplary block diagram of electrical test point positioning and thin film deposition provided in one embodiment of the present invention, please refer to Figure 2 , Figure 2 The green box in the left picture is the location box of the electrical test point, and the rectangular box in the corresponding position in the right picture is the effect display diagram of the electrical test point after being covered with the deposited film.

[0070] It should be mentioned that in the above embodiment, while the probe module 130 performs electrical parameter detection, a bias voltage may be applied to the milled power device to be tested, such as applying a gate-source voltage of 0 to 20 volts, to assist in realizing electrical parameter detection.

[0071] In some embodiments, the control module 120 further receives the target image sent by the scanning electron microscope unit; and constructs a three-dimensional structural model of the power device to be tested based on a plurality of the target images;

[0072] Sorting the target electrical parameters collected multiple times at any electrical test point in time sequence to obtain a change trend of the electrical parameters; determining whether there is an abnormality at the current electrical test point based on the change trend of the electrical parameters;

[0073] If there is an abnormality in the electrical test point, an abnormality mark is made at the location of the electrical test point in the three-dimensional structural model.

[0074] It should be noted that by analyzing the change trend of the target electrical parameters collected multiple times at any electrical test point, it is possible to capture the electrical parameter drift caused by structural exposure during the milling process in real time according to its change trend, and identify whether the power device to be tested has a progressive failure, such as hot carrier injection damage. It is understandable that, assuming that as the milling is layer by layer, the corresponding electrical parameters are getting closer and closer to their preset ideal values, it can be said that there is no progressive failure problem at the electrical test point, and there is no abnormality. If the corresponding electrical parameters deviate more and more from their preset ideal values, it can be said that there is a progressive failure problem at the electrical test point, that is, there is an abnormality. When it is determined that there is an abnormality at the electrical test point, an abnormal mark is added to the corresponding position in the three-dimensional structure model to achieve the fusion of the layer-by-layer electrical parameters and the three-dimensional structure model. In some embodiments, the marking of the abnormal area can be achieved by voxel mapping. The abnormal mark can be set with different marks according to different electrical detection points, such as oxide layer cracks, metal migration path abnormalities, etc.

[0075] Figure 3 For an example diagram of a three-dimensional structure model provided in an embodiment of the present invention, please refer to Figure 3 , Figure 3 The gate oxide cracks and leakage current abnormal areas of the power device under test are exemplarily displayed.

[0076] In some embodiments, the control module 120 further obtains a change amount between target electrical parameters detected by two adjacent electrical parameter tests of the same electrical test point;

[0077] If the change amount is greater than or equal to a preset change threshold, a milling pause signal is sent to the focused ion beam unit to instruct the focused ion beam unit to pause milling, and an imaging signal is sent to the scanning electron microscope unit to instruct the scanning electron microscope unit to scan and image the current electrical test point, obtain a structural image and send it to the control module 120;

[0078] The control module 120 determines the defect type of the current electrical test point by performing defect recognition on the structural image.

[0079] Specifically, when a sudden change in the target electrical parameters of the same electrical test point is detected, such as a sudden increase in the leakage current and exceeding the corresponding leakage current change threshold, a pause milling signal is sent to the focused ion beam unit to automatically pause milling. In addition, an imaging signal is sent to the scanning electron microscope unit to instruct the scanning electron microscope unit to perform scanning imaging, and the imaging magnification can be less than or equal to 100kX (k represents 1000, and X represents the magnification). Based on the obtained structural image, defect identification is performed, such as using a neural network model for defect identification and classification, to obtain the defect type of the current electrical test point. In this way, abnormal monitoring of sudden changes in target electrical parameters can be achieved.

[0080] In some embodiments, the focused ion beam-scanning electron microscope module 110 and the probe module 130 are integrated in the same vacuum chamber, and the vacuum chamber has a probe station 150 and a sample supporting platform 160 built in. The probe station 150 and the sample supporting platform 160 are located on the same platform, and the probe station 150 and the sample supporting platform 160 are completely or partially overlapped, and the power device to be tested is located at the overlapping part of the probe station 150 and the sample supporting platform 160.

[0081] It should be noted that the above configuration can avoid moving the power device under test during the test process. By controlling the focused ion beam-scanning electron microscope module 110 and the probe module 130, layer-by-layer milling, scanning imaging, and electrical parameter detection of the power device under test can be achieved.

[0082] In some embodiments, the local gas injection module 140, such as a vapor deposition device, is also integrated into the vacuum chamber.

[0083] In some embodiments, the vacuum chamber is connected to a preset vacuum pump 170 to keep the interior of the chamber in a vacuum state.

[0084] The power device testing apparatus in the above embodiment can be applied to the application scenarios of internal defect testing and analysis of power devices such as IGBT (Insulated Gate Bipolar Transistor) and GaN HEMT, and realize the correlation analysis between the three-dimensional structural characterization of internal defects and electrical properties.

[0085] Please refer to Figure 4 This embodiment further provides a power device testing method based on the power device testing apparatus as described in any one of the above items, including:

[0086] S410: Control the focused ion beam unit to perform a milling operation on the power device to be tested.

[0087] S420: Control the scanning electron microscope unit to scan and image the surface of the power device to be tested that has completed a single milling to obtain a target image; locate the electrical test points of the power device to be tested in the target image to obtain coordinate information of the electrical test points.

[0088] S430: Based on the coordinate information, a probe control signal is generated and sent to the probe module 130 to instruct the probe module 130 to move its probe to a position corresponding to the coordinate information based on the probe control signal, so as to perform electrical parameter detection on the electrical test point and obtain target electrical parameters.

[0089] It should be noted that the execution subject of the power device testing method in this embodiment is the control module 120 in the power device testing device. Therefore, the power device testing method in this embodiment can achieve the technical effect achieved by the power device testing device described in any of the above embodiments by executing the above control steps, which will not be repeated here.

[0090] The power device testing method in the above embodiment is explained below with a specific embodiment.

[0091] First, the control module 120 obtains the test requirements, and plans the scanning path and the electrical test path based on the test requirements. Secondly, based on the number of milling times and the single milling depth, a milling signal is generated and sent to the focused ion beam unit to instruct the focused ion beam unit to complete the milling of the power device to be tested one by one according to a preset time interval, and the depth of each milling is the single milling depth, until the cumulative number of milling times reaches the target number of milling times. Then, when each milling is completed, the scanning electron microscope unit performs scanning imaging and electrical test point positioning according to the scanning path planned by the control module 120, and feeds back the coordinate information obtained by positioning to the control module 120. Afterwards, the control module 120 generates a vapor deposition signal based on the electrical test path and the received coordinate information and sends it to the vapor deposition equipment; the vapor deposition equipment performs vapor deposition on the electrical test points one by one based on the vapor deposition signal. Next, the control module 120 generates a probe control signal based on the electrical test path and the received coordinate information and sends it to the probe module 130; the probe module 130 completes the electrical parameter detection of multiple electrical test points based on the test sequence in the probe control signal, and feeds back to the control module 120. Finally, the control module 120 integrates the target electrical parameters layer by layer with the three-dimensional structure model to complete the abnormal identification and marking of the electrical test points.

[0092] In some embodiments, an electronic device is also provided, which may be a server, and its internal structure is shown in FIG. Figure 5As shown. The electronic device includes a processor, a memory, a network interface and a database connected via a system bus. The processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile and / or volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the electronic device is used to communicate with an external client via a network connection. When the computer program is executed by the processor, the functions or steps on the server side of the above method are implemented.

[0093] In some embodiments, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented: controlling a focused ion beam unit to perform a milling operation on a power device to be tested; controlling a scanning electron microscope unit to scan and image the surface of the power device to be tested that has completed a single milling operation to obtain a target image; locating electrical test points of the power device to be tested in the target image to obtain coordinate information of the electrical test points; and generating a probe control signal based on the coordinate information and sending it to the probe module 130 to instruct the probe module 130 to move its probe to a position corresponding to the coordinate information based on the probe control signal to perform electrical parameter detection on the electrical test points, obtain target electrical parameters, and provide feedback.

[0094] In some embodiments, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented: controlling a focused ion beam unit to perform a milling operation on a power device to be tested; controlling a scanning electron microscope unit to scan and image the surface of the power device to be tested that has completed a single milling operation to obtain a target image; locating electrical test points of the power device to be tested in the target image to obtain coordinate information of the electrical test points; based on the coordinate information, generating a probe control signal and sending it to the probe module 130 to instruct the probe module 130 to move its probe to a position corresponding to the coordinate information based on the probe control signal, so as to perform electrical parameter detection on the electrical test points, obtain the target electrical parameters and feedback them.

[0095] It should be noted that the above functions or steps that can be implemented by the computer-readable storage medium or electronic device can refer to the relevant descriptions on the server side and the client side in the aforementioned method embodiment. To avoid repetition, they will not be described one by one here.

[0096] The flow chart and block diagram in the accompanying drawings illustrate the possible implementation architecture, function and operation of the method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0097] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A power device testing device, characterized in that: include: A focused ion beam-scanning electron microscope module, whose focused ion beam unit performs milling operations on the power device to be tested; The scanning electron microscope unit scans and images the surface of the power device to be tested that has completed a single milling operation to obtain a target image; locates the electrical test point of the power device to be tested in the target image to obtain the coordinate information of the electrical test point, and feeds the coordinate information back to the control module; A control module, which generates a probe control signal based on the coordinate information and sends the signal to the probe module; The probe module moves its probe to a position corresponding to the coordinate information based on the probe control signal, so as to detect electrical parameters of the electrical test point, obtain target electrical parameters and feed them back to the control module.

2. The power device testing device according to claim 1, characterized in that: The control module is also used to obtain test requirements, which include target milling times and single milling depth; Based on the milling times and the single milling depth, a milling signal is generated, wherein the milling signal is used to instruct the focused ion beam unit to complete the milling of the power device to be tested one by one at preset time intervals until the accumulated milling times reaches the target milling times.

3. The power device testing device according to claim 2, characterized in that: The test requirement also includes a to-be-tested area, which is a preset area where the electrical test points are located, and the to-be-tested area corresponds to the electrical test points one by one; The control module is further used for, when there are multiple areas to be tested in the test requirement, performing electrical test path planning based on the position distribution of the multiple areas to be tested in the power device to be tested, so as to obtain an electrical test path, wherein the electrical test path specifies a sequential test order of the multiple areas to be tested; If the coordinate information of the plurality of electrical test points is received, the probe control signal is generated based on the electrical test path and the coordinate information to instruct the probe module to complete the electrical parameter detection of the plurality of electrical test points in the sequential test order.

4. The power device testing device according to claim 3, characterized in that: If there are multiple probes in the probe module and multiple electrical test points, the probe module assigns tasks to each probe based on the number of probes, the electrical test path in the probe control signal, and the coordinate information to determine the detection path of each probe; Based on the detection path of each probe, each probe is independently controlled to complete the electrical parameter detection of the plurality of electrical test points.

5. The power device testing device according to claim 1, characterized in that: The power device testing device further comprises: The local gas injection module is used to purge the milling residues at and around the electrical test point by means of gas injection before the probe module performs electrical parameter detection.

6. The power device testing device according to claim 5, characterized in that: The local gas injection module is a vapor deposition device, which releases a gaseous precursor to the electrical test point before the probe module performs electrical parameter detection, so as to complete the purging of milling residues at and around the electrical test point and form a deposited film on the surface of the electrical test point; When the probe performs electrical parameter detection on the electrical test point, the probe makes electrical contact with the deposited film on the surface of the electrical test point to complete the electrical parameter detection.

7. The power device testing device according to claim 6, characterized in that: The vapor deposition device performs vapor deposition on the electrical test point upon receiving the vapor deposition signal sent by the control module. The vapor deposition signal is generated and sent by the control module before sending the probe control signal. The time interval between sending the vapor deposition signal and the probe control signal is a preset interval. The vapor deposition signal is generated based on the coordinate signal.

8. The power device testing device according to claim 1, characterized in that: The control module also receives the target image sent by the scanning electron microscope unit; and constructs a three-dimensional structural model of the power device to be tested based on a plurality of the target images; Sorting the target electrical parameters collected multiple times at any electrical test point in time sequence to obtain a change trend of the electrical parameters; determining whether there is an abnormality at the current electrical test point based on the change trend of the electrical parameters; If there is an abnormality in the electrical test point, an abnormality mark is made at the location of the electrical test point in the three-dimensional structural model.

9. The power device testing device according to claim 1, characterized in that: The control module further obtains a change amount between target electrical parameters detected by two adjacent electrical parameter detections of the same electrical test point; If the change amount is greater than or equal to a preset change threshold, a milling pause signal is sent to the focused ion beam unit to instruct the focused ion beam unit to pause milling, and an imaging signal is sent to the scanning electron microscope unit to instruct the scanning electron microscope unit to scan and image the current electrical test point, obtain a structural image and send it to the control module; The control module determines the defect type of the current electrical test point by performing defect recognition on the structural image; The focused ion beam-scanning electron microscope module and the probe module are integrated in the same vacuum chamber, and the vacuum chamber has a built-in probe station and a sample carrying platform. The probe station and the sample carrying platform are located on the same platform, and the probe station and the sample carrying platform completely or partially overlap, and the power device to be tested is located at the overlapping part of the probe station and the sample carrying platform.

10. A power device testing method based on the power device testing apparatus according to any one of claims 1 to 9, characterized in that: include: Controlling the focused ion beam unit to perform a milling operation on the power device to be tested; Controlling the scanning electron microscope unit to scan and image the surface of the power device to be tested that has completed a single milling operation to obtain a target image; locating the electrical test point of the power device to be tested in the target image to obtain coordinate information of the electrical test point; Based on the coordinate information, a probe control signal is generated and sent to the probe module to instruct the probe module to move its probe to a position corresponding to the coordinate information based on the probe control signal, so as to perform electrical parameter detection on the electrical test point and obtain target electrical parameters.

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