System for continuous test of array device, electronic equipment and storage medium

Abstract

The invention provides a system for continuous testing of array devices, electronic equipment and a storage medium. The system comprises a first upper computer and a probe station, the first upper computer sends a scanning path to the probe station and controls the probe station to scan and test the to-be-tested array device: a tray of the probe station moves according to a path point set by the scanning path, and after the tray reaches a designated position, the tray is moved upwards to enable a probe to be connected with an electrode of the to-be-tested array device, and the to-be-tested array device is detected; and testing the to-be-tested array device through the electronic test equipment according to a test instruction sent by the second upper computer, and repeating the process until all electrodes of the to-be-tested array device are tested. The scanning test of any test parameter of any array device can be realized, data visualization is carried out by combining the detection position coordinate and the test result of the position, and comprehensive and effective test data is provided for array devices in different shapes.

Description

Technical Field

[0001] The present invention relates to the technical field of device testing, and in particular to a system, electronic equipment and storage medium for continuous testing of array devices. Background Art

[0002] When testing array devices, the main technique in the related art is to model the array shape to control the connection between the probe and the devices at different positions to complete batch testing. Since multiple chips are distributed on a wafer and multiple devices are distributed on a chip, if the chips on the wafer or the devices on the chip are not completely aligned regularly due to some considerations during design, this will cause the interval step of each device to become unstable and difficult to model. This can of course be solved by editing the nested scan path, but in this mode, the complexity of the test results of the entire array device is greatly increased when summarizing and collating. Summary of the invention

[0003] The present invention proposes a system, electronic device and storage medium for continuous testing of array devices to solve the technical problems of the existing device testing method, which has complex test mode settings and high complexity in test result aggregation when the arrangement is not completely regular.

[0004] In order to solve the above technical problems, the present invention provides a system for continuous testing of array devices, comprising a first host computer and a probe station;

[0005] The first host computer sends a scanning path to the probe station, and controls the probe station to perform a scanning test on the array device to be tested: the tray of the probe station moves according to the path points set by the scanning path, and after reaching the specified position, the tray is moved up to connect the probe and the electrode of the array device to be tested, and the array device to be tested is tested by the electronic testing equipment according to the test instructions sent by the second host computer, and the above process is repeated until all the electrodes of the array device to be tested are tested.

[0006] Preferably, the first host computer controls the movement of the tray of the probe station up, down, left, and right through the script running environment and communication instruction set provided by the probe station.

[0007] Preferably, the first host computer and the second host computer communicate by controlling logs.

[0008] Preferably, when the probe station performs a scanning test on the array device to be tested, it imports or creates a new two-dimensional scanning path from the library of the first host computer; the tray control unit of the first host computer generates a control instruction set according to the scanning path and issues a movement instruction to the probe station; after the probe station controls the tray to complete the instruction, it feeds back the position information to the first host computer, and the first host computer writes the position information into the control log; after the device control unit of the second host computer detects the log update, it controls the electronic test equipment to perform the test according to the set test parameters; on the one hand, the detection result is combined with the position information to complete the data aggregation, and on the other hand, it feeds back the "completion" signal to the control log to perform the test of the next position; after the tray control unit of the first host computer detects the "completion" signal, it issues the next instruction and enters the test of the next position, that is, the next device; this cycle is repeated until all instructions in the control instruction set are completed, that is, the scanning test of the preset array is completed.

[0009] Preferably, during the entire test process, the second host computer aggregates all test data to complete data presentation, and saves the data after the test is completely completed.

[0010] Preferably, the scanning path includes: a minimum repeating unit scanning path and a two-dimensional path scanning path;

[0011] The minimum repeating unit scanning path is used for array devices with incomplete periodic arrangement;

[0012] The two-dimensional scanning path is used to improve the accuracy of alignment between the probe and the device under test through a displacement compensation algorithm;

[0013] The two-dimensional scanning path is compatible with the one-dimensional scanning case.

[0014] Preferably, the displacement compensation algorithm corrects the situation in which the distance between devices deviates due to plastic deformation of the wafer where the array devices are located by setting an offset value.

[0015] Preferably, the minimum repeating unit scanning path includes a nine-square grid minimum unit, and the nine-square grid minimum unit is Ux; Uy; unit; center_x = 0; center_y = 0; relative_points = [(0,0), (-unit, 0), (-2*unit, 0), (0, unit), (-unit+100, unit), (-2*unit-135, unit), (0, 2*unit), (-unit, 2*unit), (-2*unit, 2*unit)], wherein Ux represents the length of the nine-square grid in the x direction; Uy represents the length of the nine-square grid in the y direction; unit represents the distance between each device in the nine-square grid, and the unit is micron; center_x and center_y represent the center point position of the starting reference test device; +100 and -135 represent the relative offset of the corresponding device.

[0016] The present invention also provides an electronic device, comprising: a memory, a processor and a computer program, wherein the computer program is stored in the memory and is configured to be executed by the processor to implement the above system.

[0017] The present invention also provides a computer-readable storage medium, in which a computer program is stored. The computer program is executed by a processor to implement the above system.

[0018] The beneficial effects of the present invention include at least: the first host computer and the second host computer of the continuous test system for array devices provided by the embodiment of the present invention can coordinate the automatic probe station with the electronic test equipment to perform continuous scanning test on the array device to be tested in mutual communication, and generate test results. The second host computer can also obtain the detection position of the device to be tested through the control log, correspond the test result of each position to its position, mark the results with different colors, and save them in EXCEL. Therefore, this scheme can realize the scanning test of any test parameters for any array device, and then combine the detection position coordinates and the test results of the position for data visualization, providing comprehensive and effective test data for array devices of different shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the implementation process of the system of the embodiment of the present invention;

[0020] Figure 2 A schematic diagram of system structure connection of an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the internal communication structure of the system structure of an embodiment of the present invention;

[0022] Figure 4A schematic diagram of the structure of an array device and its minimum repeating unit according to an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of a result of a scan test of an array device provided by an embodiment of the present invention;

[0024] Figure 6 A schematic diagram of an intermediate process of scanning test of an array device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a system for continuous testing of array devices, including a first host computer and a probe station.

[0027] The first host computer sends a scanning path to the probe station, and controls the probe station to perform a scanning test on the array device to be tested: the tray of the probe station moves according to the path points set by the scanning path, and after reaching the specified position, the tray is moved up to connect the probe and the electrode of the array device to be tested, and the array device to be tested is tested by the electronic testing equipment according to the test instructions sent by the second host computer, and the above process is repeated until all the electrodes of the array device to be tested are tested.

[0028] Specifically, the system structure is connected as follows Figure 2 As shown, it includes a first host computer, a second host computer, a probe station and an electronic testing device; the probe station is connected to the electronic testing device, the probe station is connected to the first host computer, the electronic testing device is connected to the second host computer, and the first host computer is connected to the second host computer.

[0029] like Figure 3As shown, the units and control directions included in each result in the system are as follows. Specifically, a two-dimensional scanning path is imported from the library of the first host computer or a new two-dimensional scanning path is created. The tray control unit thereon generates a control instruction set according to the scanning path and issues an instruction to the tray of the probe station; after the tray completes the instruction, it feeds back the position information, and the tray control unit writes the position information into the control log; after the device control unit on the second host computer detects that the control log is updated, it controls the electronic test equipment to perform the test according to the set test parameters; on the one hand, the test result is stored and the data is visualized in combination with the position information, and on the other hand, a "completion" signal is fed back to the control log to perform the test at the next position; after the tray control unit detects the "completion" signal, it issues the next instruction and enters the test of the next position, i.e., the next device; this process is repeated until all the instructions in the control instruction set are completed, i.e., the scanning test of the preset array is completed.

[0030] In this embodiment, the first host computer is any computer device equipped with a communication protocol or software with the probe station. It uses the script running environment provided by the probe station product manufacturer and the communication instruction set provided in the instruction manual to control the movement of the tray part in the probe station up, down, left and right.

[0031] Since the probes on the probe station are connected to the electronic testing equipment, it is often difficult to translate the probes as a whole. Therefore, in this embodiment, the array devices are traversed in a manner that the probes are stationary and the lower tray moves in the opposite direction.

[0032] The first host computer is set to store a scanning path library of different scanning paths for the convenience of secondary use by testers. When considering the diversity of scanning paths, the method of superimposing the minimum repeatable unit of scanning paths is specially adopted to increase the adaptability of the program, that is, the final scanning path can be a path-in-path mode.

[0033] The embodiment of the present invention is described by taking a schematic diagram of the structure of an array device and its minimum repeating unit as an example. Figure 4As shown, its minimum repeating unit is a square grid composed of nine devices. However, the electrodes are not all in the same position of the device, which means that the series scanning test cannot be completed by simple linear repetition. At this time, it is necessary to model the nine-square grid as the minimum repeating unit and combine it with the scanning path of the array device to complete the matching. The nine-square grid model at this time is: Ux=20000;Uy=20005;unit=6666;center_x=0;center_y=0;relative_points=[(0,0),(-unit,0),(-2*unit,0),(0,unit),(-unit+100,unit),(-2*unit-135,unit),(0,2*unit),(-unit,2*unit),(-2*unit,2*unit)].

[0034] Among them, Ux=20000 represents the length of this nine-square grid in the x direction; Uy=20005 represents the length of this nine-square grid in the y direction; unit=6666 represents the distance between each device in the nine-square grid, and the unit is micron; center_x and center_y represent the center point position setting of the reference test device starting in the upper left corner.

[0035] The other eight devices are used to calibrate the relative position relative to the reference device. It is worth noting that this scan is from the upper left corner of the wafer to the lower right corner, so the x coordinate appears as -unit in the position relationship because this requires the tray to move the wafer on it in the negative direction. The scanning path is generated by setting the indentation of each row and the number of nine-square grids per row. For example, the input parameters are (2,3), (1,5), (0,7), (1,5), (1,5), (2,3) to complete Figure 4 The array device scanning path shown, where (2,3) represents the first row of repeating units, indented by two, and then including three repeating units. The generated scanning points are positions1 = [(0,0), (-1,0), (-2,0), (1,1), (0,1), (-1,1), (-2,1), (-3,1), (2,2), (1,2), (0,2), (-1,2), (-2,2), (-3,2), (-4,2), (1,3), (0,3), (-1,3), (-2,3), (-3,3), (1,4), (0,4), (-1,4), (-2,4), (-3,4), (0,5), (-1,5), (-2,5)].

[0036] It should be mentioned that if the user inputs the parameters (12,3), (11,4), (10,5), (11,4), (11,4), (12,3), the program will still generate the same scanning point positions1. This is because the scanning point records the relative relationship of the position, and the increase in the first line indent does not affect the relative relationship. If the user slices the wafer, for example, cuts off the two right columns, and changes the shape of the array to be measured, new parameters (2,3), (1,4), (0,5), (1,4), (1,4), (2,3) need to be entered. The generated scanning points positions2 = [(0,0), (-1,0), (-2,0), (1,1), (0,1), (-1,1), (-2,1), (2,2), (1,2), (0,2), (-1,2), (-2,2), (1,3), (0,3), (-1,3), (-2,3), (1,4), (0,4), (-1,4), (-2,4), (0,5), (-1,5), (-2,5)].

[0037] These scan paths can be saved in the scan path library for direct use next time. The naming of "positions" depends on the user's preference. Here, each point in positions1 and positions2 corresponds to a minimum repeating unit, that is, a nine-square grid. Therefore, when the 23 points in positions1 are completed, the scan test of the entire array of 23*9=207 devices is completed. If the user wants to scan an array with a more irregular shape, the scan points can be described by directly editing "positions" instead of generating them by inputting parameters. The coordinates in "positions" can be decimals. When moving between devices in different positions, the tray control program will first lower the tray by 500um before moving it. After reaching the corresponding position, it will rise 500um to re-contact the probe with the device electrode. This protects both the probe tip from damage and the device.

[0038] After arriving at each new device position, the tray control unit will send message = 'TestPython logging to Velox({},{})'.format(position_number,relation_number) to the control log, where position_number and relation_number are determined by specific values, where position_number<23,relation_number<9. For example, Test Python logging to Velox(15,4) means the 4th device in the 15th nine-square grid. The two-dimensional scanning mentioned above is fully compatible with the one-dimensional case, which means that only relative_points = [(0,0)] is required, and then the input parameter is set to (0,128) to complete the scanning test of a row of 128 devices.

[0039] The size of the electrode on each device is a square with a side length of 80um. If the predetermined position of the probe is set to the center of the electrode, the allowable error is ±40um. If you want the probe to have better contact with the electrode, you need to ensure that the probe does not exceed ±20um from the center of the electrode. The minimum displacement distance of the tray on the probe station is 4um, which is theoretically sufficient to complete the task. However, since the side length of the nine-square grid is 20000um, the displacement of the farthest nine-square grid is (-40000, 100000). If the wafer undergoes a slight deformation, then there will be a situation where a slight error can lead to a huge difference when determining the position of the last device - the allowable deformation in the y direction is At the same time, due to the two-dimensional scanning, the errors generated are superimposed, which further amplifies the uncertainty. Therefore, displacement compensation algorithms for different deformations came into being. The displacement offsets considered in the program include: the in-plane displacement offset caused by the wafer bumps and the non-orthogonal problems in the x and y directions caused by the wafer tape-out. The in-plane displacement offset caused by the wafer bumps refers to the fact that during the production or use process, two points in the plane that are Lum apart will deviate from the original plane due to the slight protrusion of the wafer. At this time, the distance between the two is often slightly less than Lum, and the specific value depends on the degree of bumps. The non-orthogonal problem in the x and y directions caused by the tape-out is also a problem unique to two-dimensional scanning. It means that when the devices are aligned in the x direction, the connection lines of the same column of devices are not perpendicular to the x direction. For the wafer x and y in this embodiment, the angle between them is slightly greater than 90 degrees, so when the tray is moved in the positive direction of the y axis, the position where the next device appears will be on the left side of the expected position. Since this error value is proportional to the displacement in the direction and the error ratio of the same batch of wafers is the same, it can be ruled out as an accidental error.

[0040] In this embodiment, the displacement compensation algorithm has a pre-scan before the formal scan. The pre-scan will be performed when the light is turned on and only the first device in each nine-square grid will be scanned. Therefore, its stepping is 20000um. Every time it comes to a new position, the image information under the microscope will be read. The displacement of the device position is recorded as δx and δy by using BFMatcher for feature matching and comparison with the offset of the first image. 23 δx and δy are stored in the same array. When the formal scan is performed, the tray displacement will be superimposed on δx and δy on the basis of x*20000um and y*20000um to ensure that the probe is in the relative center position of the electrode. It can be considered that the compensation amount of the other eight devices in each nine-square grid is the same as that of the first device, and no separate calibration is performed to save time.

[0041] In the case of solving the precise alignment of the position, the second host computer is needed to complete the different parameter tests and data processing of the position. The present embodiment uses the Keithley 2636B source test unit as the electronic test equipment, which is connected to the second host computer via USB, but other connection methods only need simple modifications to achieve the same effect. It should be noted that the program in the second host computer only needs to be slightly modified to complete other electronic test equipment that can be controlled by the host computer instructions. Before the device control unit of the second host computer, the first is some initialization parts. When running the program, a pop-up window will be displayed to ask the user to save the address of the test data for later viewing.

[0042] This embodiment uses 2636B to test the reverse bias dark current of Si-based PIN devices. It is necessary to give its device address. In this embodiment, instrument_address = "USB0::0x05E6::0x2636::4544659::INSTR". This address is unique and fixed for each device. Then try to open the communication with the device instrument = rm.open_resource (instrument_address); instrument.timeout = 10000; print ("Instrument opened successfully!"). The device timeout is set to 10000ms, that is, 10s. This is because the 2636 source meter requires a longer test time when testing weak currents. If the timeout is not increased artificially, frequent errors will be reported and readings cannot be read. It should be noted that the timeout refers to the maximum waiting time rather than the time required to test each data point. The test parameters are set as enumeration method: voltages = [-30, -60, -90, -120, -150, -180, 2]. The test parameter settings can be modified arbitrarily, such as reducing the step size but increasing the test time. It can also be expressed in an analytical way, such as for voltage in range (2, -181, -2), which means the step size is from 2V to -180V with a step size of -2V. The program will perform the following operations for each voltage test point: instrument.write(f"smua.source.levelv={vol tage}"); instrument.write("printnumber(smua.measure.iv())") writes the voltage to 2636 and makes it input the actual voltage and current into the communication unit, and then reads this data to the second host computer through response=instrument.read(), and print(f"Voltage:{voltage}V,RealVoltage:{realvoltage}V,Current:{current}A") is displayed in the program interaction window to allow users to quickly judge whether the data is reasonable. Since the test environment needs to be in a dark scene, the "2V" is used to judge whether the device is normal and whether the probe and electrode are in good contact. At this time, the actual voltage often does not reach 2V. This is because the on-state current of the device is higher than the limit current set by the 2636 source meter. Therefore, the source meter increases the internal resistance and reduces the current to the limit current. This also divides the total voltage of 2V so that the measured voltage across the device is less than 2V.After the voltage test is completed, the storage unit in the second host computer will use the def check_file(shared_file_path) function combined with the position information read in the control log "Test Python logging to Velox(15,4)" to associate the test data with (15,4) and save it in an EXCEL file named measure_15_4.xlsx. In the data visualization part, you only need to modify the feature value to be extracted, such as specific_row=df[df['Voltage(V)']==voltage_value], let voltage_value=-180, the program will index the required row, extract the corresponding current test results and the position data of the device in the entire array, and then output the current test results of all devices at -180V to a new EXCEL file corresponding to their positions one by one and mark them with color scale rules. Figure 5 Results shown. Figure 6 It is a real-time summary result diagram captured at random moments during the actual measurement process, which completes the test process of the entire array device.

[0043] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. Only the preferred embodiments of the present invention are expressed. The description is more specific and detailed, but it cannot be understood as limiting the scope of the present invention. As long as there is no contradiction in the combination of these technical features, they should be considered as within the scope of this specification.

[0044] It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A system for continuous testing of array devices, characterized in that: Including the first host computer and the probe station; The first host computer sends a scanning path to the probe station, and controls the probe station to perform a scanning test on the array device to be tested: the tray of the probe station moves according to the path points set by the scanning path, and after reaching the specified position, the tray is moved up to connect the probe and the electrode of the array device to be tested, and the array device to be tested is tested by the electronic testing equipment according to the test instructions sent by the second host computer, and the above process is repeated until all the electrodes of the array device to be tested are tested.

2. A system for continuous testing of array devices according to claim 1, characterized in that: The first host computer controls the movement of the tray of the probe station up, down, left, and right through the script running environment and communication instruction set provided by the probe station.

3. A system for continuous testing of array devices according to claim 1, characterized in that: The first host computer and the second host computer communicate with each other by controlling logs.

4. A system for continuous testing of array devices according to claim 3, characterized in that: When the probe station performs a scanning test on the array device to be tested, it imports or creates a new two-dimensional scanning path from the library of the first host computer; the tray control unit of the first host computer generates a control instruction set according to the scanning path and issues a movement instruction to the probe station; after the probe station controls the tray to complete the instruction, it feeds back the position information to the first host computer, and the first host computer writes the position information into the control log; after the device control unit of the second host computer detects the log update, it controls the electronic test equipment to perform the test according to the set test parameters; on the one hand, the detection result completes the data aggregation in combination with the position information, and on the other hand, it feeds back the "completion" signal to the control log to perform the test of the next position; after the tray control unit of the first host computer detects the "completion" signal, it issues the next instruction and enters the test of the next position, i.e., the next device; this process is repeated until all the instructions in the control instruction set are completed, i.e., the scanning test of the preset array is completed.

5. A system for continuous testing of array devices according to claim 4, characterized in that: During the entire test process, the second host computer aggregates all test data to complete data presentation, and saves the data after the test is completely completed.

6. A system for continuous testing of array devices according to claim 1, characterized in that: The scanning path includes: a minimum repeating unit scanning path and a two-dimensional path scanning path; The minimum repeating unit scanning path is used for array devices with incomplete periodic arrangement; The two-dimensional scanning path is used to improve the accuracy of alignment between the probe and the device under test through a displacement compensation algorithm; The two-dimensional scanning path is compatible with the one-dimensional scanning case.

7. A system for continuous testing of array devices according to claim 6, characterized in that: The displacement compensation algorithm corrects the situation where the wafer where the array device is located has plastic deformation, resulting in the deviation of the device spacing, by setting the offset value.

8. The system for continuous testing of array devices according to claim 6, characterized in that: The minimum repeating unit scanning path includes a minimum unit of a nine-square grid, and the minimum unit of the nine-square grid is Ux; Uy; unit; center_x=0; center_y=0; relative_points=[(0,0),(-unit,0),(-2*unit,0),(0,unit),(-unit+100,unit),(-2*unit-135,unit),(0,2*unit),(-unit,2*unit),(-2*unit,2*unit)], wherein Ux represents the length of the nine-square grid in the x direction; Uy represents the length of the nine-square grid in the y direction; unit represents the distance between each device in the nine-square grid, and the unit is micron; center_x and center_y represent the center point position of the starting reference test device; +100 and -135 represent the relative offset of the corresponding device.

9. An electronic device, comprising: A memory, a processor and a computer program, characterized in that the computer program is stored in the memory and is configured to be executed by the processor to implement the system according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the system according to any one of claims 1 to 8.

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