SMU automatic calibration system

Abstract

The utility model discloses an SMU automatic calibration system, comprising a program control resistor module, the program control resistor module comprises a UART communication module, and the UART communication module is connected with a programmable resistor module through a control unit; the programmable resistor module is respectively connected with the user interface and the ADC data acquisition module through the universal meter, the ADC data acquisition module feeds back data to the user interface, the user interface sends the data to the UART communication module, and the ADC data acquisition module is connected with the programmable resistor module through the SMU module. The utility model discloses an efficient and accurate SMU automatic calibration system. Measurement errors can be adjusted and compensated, and the reliability of test results is improved.

Description

Technical Field

[0001] This utility model relates to the field of electronic measurement and calibration technology, and in particular to an SMU automatic calibration system. Background Technology

[0002] With the rapid development of electronic technology and the semiconductor industry, higher demands are being placed on the measurement accuracy and efficiency of source measurement units (SMUs). SMUs are key components in modern electronic test and measurement systems, widely used in the electrical characteristic testing of semiconductor devices, materials research, and other precision measurement fields. Traditional SMU calibration methods typically rely on manual setup and adjustment, which is not only cumbersome but also easily affected by the operator's experience and skills. This manual intervention leads to a decrease in the stability and reliability of calibration results, thus affecting the accuracy of test results.

[0003] Therefore, there is an urgent need to develop an automated SMU calibration system that can reduce manual intervention, optimize the calibration process, improve SMU performance, and meet the demands of modern semiconductor testing for high efficiency and accuracy. Utility Model Content

[0004] This invention overcomes the shortcomings of the prior art and provides an efficient and accurate SMU automatic calibration system; it can adjust and compensate for measurement errors and improve the reliability of test results.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an SMU automatic calibration system, comprising: a programmable resistor module, the programmable resistor module including a UART communication module, the UART communication module being connected to the programmable resistor module through a control unit; the programmable resistor module being connected to a user interface and an ADC data acquisition module through a multimeter, the ADC data acquisition module feeding back data to the user interface, the user interface sending data to the UART communication module, and the ADC data acquisition module being connected to the programmable resistor module through the SMU module.

[0006] In a preferred embodiment of this invention, the programmable resistor module further includes a power supply circuit for supplying power to the UART communication module and the control unit.

[0007] The UART communication module includes a communication chip and a communication interface, and the control unit includes an FPGA module. The communication chip is connected to the power supply circuit through the communication interface, and the communication chip is also connected to the FPGA module. The FPGA module is connected to the programmable resistor module.

[0008] In a preferred embodiment of this utility model, the programmable resistor module includes a bridged resistor structure, which includes multiple resistor modules connected by relays. The relays switch the series and parallel connection of the resistor modules in the bridged resistor structure.

[0009] In a preferred embodiment of this utility model, the multiple resistor modules include resistor module one, resistor module two, resistor module three, resistor module four, resistor module five, and resistor module six. Resistor modules one, two, three, four, five, and six are connected by several relays. By switching the on and off of the relays in the bridged resistor structure, the series and parallel connection of the resistor modules can be switched.

[0010] In a preferred embodiment of this utility model, the resistor module includes: resistors R1, R2, and R3 connected in series; the connection node between resistors R1 and R2, the connection node between resistors R2 and R3, and the other end of resistor R3 are respectively connected to one end of the adjusting potentiometer VR1 through relays K4A, K6A, and K5A, and the other end of the adjusting potentiometer VR1 is connected to relay K5A at the same point as the control terminal;

[0011] Resistor module two includes: resistors R4, R5, and R6 connected in series; the input terminal of resistor R4 is connected to resistor R3 via relay K5A; the connection point of resistors R4 and R5, the connection point of resistors R5 and R6, and the other end of resistor R7 are respectively connected to one end of adjusting potentiometer VR2 via relays K7A, K9A, and K8A; the other end of adjusting potentiometer VR2 is connected to relay K8A at the same point as the control terminal.

[0012] Resistor module three includes: resistors R7, R8, and R9 connected in series; the input terminal of resistor R7 is connected to resistor R6 via relay K8A; the connection point between resistors R7 and R8, the connection point between resistors R8 and R9, and the other end of resistor R9 are respectively connected to one end of adjusting potentiometer VR3 via relays K10A, K12A, and K11A; the other end of adjusting potentiometer VR3 is connected to the control terminal at the same point.

[0013] Resistor module four includes: resistors R10, R11, and R12 connected in series; the connection point between resistors R10 and R11, the connection point between resistors R11 and R12, and the other end of resistor R12 are respectively connected to one end of adjusting potentiometer VR4 through relays K19A, K21A, and K20A; the other end of adjusting potentiometer VR4 is connected to relay K20A at the same point as the control terminal.

[0014] Resistor module five includes: resistors R13, R14, and R15 connected in series; the input terminal of resistor R13 is connected to resistor R12 via relay K21A; the connection point between resistors R13 and R14, the connection point between resistors R14 and R15, and the other end of resistor R15 are respectively connected to one end of adjusting potentiometer VR5 via relays K22A, K24A, and K23A; the other end of adjusting potentiometer VR5 is connected to relay K23A at the same point as the control terminal.

[0015] Resistor module six includes: resistors R16, R17, and R18 connected in series; the input terminal of resistor R16 is connected to resistor R15 via relay K23A; the connection point between resistors R16 and R17, the connection point between resistors R17 and R18, and the other end of resistor R18 are respectively connected to one end of adjusting potentiometer VR6 via relays K25A, K27A, and K26A; the other end of adjusting potentiometer VR6 is connected to relay K26A at the same point as the control terminal.

[0016] The common connection point of relays K4A, K6A, and K5A is connected to the common connection point of relays K19A, K21A, and K20A; the common connection point of relays K7A, K9A, and K8A is connected to the common connection point of relays K22A, K24A, and K23A; the common connection point of relays K10A, K12A, and K11A is connected to the common connection point of relays K25A, K27A, and K26A.

[0017] The input terminal of resistor R1 is connected to the input terminal of resistor R10 through relays K3A and K18A connected in series. The input terminal of resistor R4 is connected to the input terminal of resistor R13 through relays K2A and K17A connected in series. The input terminal of resistor R7 is connected to the input terminal of resistor R16 through relays K1A and K16A connected in series. The connection nodes of relays K3A and K18A, K2A and K17A, and K1A and K16A share a common point as output terminal A.

[0018] The control terminal of potentiometer VR3 is connected to one end of relay K13A; the control terminal of potentiometer VR6 is connected to one end of relay K30A; the other end of relay K13A is connected to the other end of relay K30A; the other end of relay K2A is connected to the input terminal of resistor R4, and a branch is connected to one end of relay K15A; the other end of relay K1A is connected to the input terminal of resistor R7, and a branch is connected to one end of relay K14A; the other end of relay K17A is connected to the input terminal of resistor R13, and a branch is connected to one end of relay K28A; the other end of relay K16A is connected to the input terminal of resistor R13, and a branch is connected to one end of relay K29A; and the other ends of relays K14A, K15A, K28A, and K29A are connected at a common point to the connection node of relays K13A and K30A.

[0019] In a preferred embodiment of this invention, the FPGA module receives operation commands from the user interface through the UART communication module, and the FPGA module outputs control signals through the GPIO interface to drive Darlington transistors to control the series and parallel connection of resistor modules in the programmable resistor module.

[0020] In a preferred embodiment of this utility model, the ADC data acquisition module includes an ADC data acquisition chip; the ADC data acquisition chip is connected to the programmable resistor module through the SMU module and is used to acquire the FPGA control signal sent by the FPGA module to the programmable resistor module; the acquisition end of the ADC data acquisition chip is connected to a multimeter to acquire the measurement results of the multimeter.

[0021] In a preferred embodiment of this utility model, the FPGA module is connected to the relay in the programmable resistor module through a Darlington transistor, which is used to drive the relay in the programmable resistor module to switch on and off, thereby realizing the series and parallel connection of the resistor modules in the programmable resistor module.

[0022] The Darlington transistor includes transistor Q1. The base of transistor Q1 is connected to the FPGA module through resistor R71. The base of transistor Q1 is connected to the emitter of transistor Q1 through resistor R72. Resistor R72 is also connected to the emitter of transistor Q2 through resistor R73. The connection point of resistors R72 and R73 is connected to the emitter of transistor Q1. The emitter of transistor Q2 is grounded. The collector of transistor Q1 is connected to the collector of transistor Q2 and serves as the OUT output terminal. The connection point of the collectors of transistors Q1 and Q2 also has a branch output via diode D1 as the COM terminal. The OUT output terminal is connected to the programmable resistor module.

[0023] In a preferred embodiment of this utility model, the adjusting potentiometers VR1, VR2, VR3, VR4, VR5, and VR6 are all digital potentiometers, and the control terminals of the digital potentiometers are connected to the FPGA module.

[0024] Compared with the prior art, the beneficial effects achieved by this utility model are as follows:

[0025] This utility model discloses an efficient and accurate automatic calibration system for SMUs; it can adjust and compensate for measurement errors, thereby improving the reliability of test results.

[0026] 1. It can adjust and compensate for measurement errors, improving the reliability of test results. It enhances measurement accuracy and consistency, reduces human error, increases testing efficiency, and ensures that the equipment maintains optimal performance in complex experimental environments. It can automatically adjust and compensate for various measurement errors, ultimately achieving more reliable test results.

[0027] 2. The series bridge resistor structure consists of multiple precision resistor modules, used to achieve high-precision current and voltage measurement. It has the ability to dynamically adjust the resistance value and ensure calibration stability under different load conditions.

[0028] 3. The programmable resistor box is composed of multiple high-precision resistor elements connected in series in a bridged structure to form a precision resistor module, in order to meet different measurement needs. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Figure 1 This is a schematic diagram of the system framework of an SMU automatic calibration system according to this utility model;

[0031] Figure 2 This is a schematic diagram of the frame structure of the ADC data acquisition module of an SMU automatic calibration system according to this utility model;

[0032] Figure 3 This is a schematic diagram of the connection between the FPGA module, Darlington transistor, and digital potentiometer in an SMU automatic calibration system according to this utility model.

[0033] Figure 4 This is a schematic diagram of the structure of a programmable resistor module in an SMU automatic calibration system according to this utility model;

[0034] Figure 5 This is a schematic diagram of a series bridge resistor structure in an SMU automatic calibration system according to this utility model;

[0035] Figure 6This is a data table for result verification in an SMU automatic calibration system according to this utility model;

[0036] Figure 7 This utility model relates to a data table for real-time data acquisition in an SMU automatic calibration system;

[0037] Among them, 1-user interface, 2-SMU module, 3-ADC data acquisition module, 4-programmable resistor module, 5-multimeter. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features therein are detailed descriptions of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features therein can be combined with each other.

[0039] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Example 1

[0040] like Figures 1-5 As shown, an SMU automatic calibration system includes: a programmable resistor module 4, which includes a UART communication module. The UART communication module is connected to the programmable resistor module through a control unit. The programmable resistor module is connected to a user interface 1 and an ADC data acquisition module 3 through a multimeter 5. The ADC data acquisition module 3 feeds back data to the user interface 1, and the user interface 1 sends data to the UART communication module. The ADC data acquisition module is connected to the programmable resistor module through an SMU module 2.

[0041] Specifically, the programmable resistor module 4 also includes a power supply circuit for supplying power to the UART communication module and the control unit. The UART communication module includes a communication chip and a communication interface, and the control unit includes an FPGA module. The communication chip is connected to the power supply circuit through the communication interface and is also connected to the FPGA module. The FPGA module is connected to the programmable resistor module. Furthermore, the programmable resistor module includes a bridged resistor structure, which comprises multiple resistor modules connected by relays. The relays switch the series and parallel connections of the resistor modules in the bridged resistor structure.

[0042] Specifically, the FPGA module connects to the relays in the programmable resistor module via Darlington transistors to drive the relays' on / off states, enabling the series and parallel connection of resistors within the programmable resistor module. The FPGA module receives operation commands from user interface 1 via the UART communication module. The FPGA module then outputs control signals through the GPIO interface to drive the Darlington transistors, controlling the series and parallel connection of resistors in the programmable resistor module. The UART communication module uses a high-frequency transmission interface to achieve high-speed and high-bandwidth data transmission, ensuring transmission rate and data integrity. The FPGA module receives user operation commands through the UART communication module and generates control signals through the GPIO interface to drive the Darlington transistors... Figure 3 The output terminal (OUT) of the Darlington transistor is connected to a relay. Adjusting the relay's operating state allows for switching between series and parallel combinations of resistor modules A1 to A6. The relay dynamically configures the resistor modules by changing the state of its contacts, thus meeting the needs of different testing conditions.

[0043] Specifically, the ADC data acquisition module 3 includes an ADC data acquisition chip; the ADC data acquisition chip is connected to the programmable resistor module through the SMU module 2, and is used to acquire the FPGA control signals sent by the FPGA module to the programmable resistor module; the acquisition end of the ADC data acquisition chip is connected to a multimeter to acquire the measurement results of the multimeter. Example 2

[0044] like Figures 1-5 As shown, an SMU automatic calibration system includes: a programmable resistor module 4, which includes a UART communication module. The UART communication module is connected to the programmable resistor module through a control unit. The programmable resistor module is connected to a user interface 1 and an ADC data acquisition module 3 through a multimeter 5. The ADC data acquisition module 3 feeds back data to the user interface 1, and the user interface 1 sends data to the UART communication module. The ADC data acquisition module is connected to the programmable resistor module through an SMU module 2.

[0045] Specifically, the programmable resistor module 4 also includes a power supply circuit for supplying power to the UART communication module and the control unit. The UART communication module includes a communication chip and a communication interface, and the control unit includes an FPGA module. The communication chip is connected to the power supply circuit through the communication interface, and the communication chip is also connected to the FPGA module. The FPGA module is connected to the programmable resistor module.

[0046] Furthermore, the UART communication module uses a high-frequency transmission interface to achieve high-speed and high-bandwidth data transmission, ensuring transmission rate and data integrity. The FPGA module receives user operation commands through the UART communication module and generates control signals through the GPIO interface to drive Darlington transistors, such as... Figure 3 The output terminal (OUT) of the Darlington transistor is connected to a relay. Adjusting the relay's operating state allows for switching between series and parallel combinations of resistor modules A1 to A6. The relay dynamically configures the resistor modules by changing the state of its contacts, thus meeting the needs of different testing conditions.

[0047] Furthermore, the programmable resistor module includes a bridged resistor structure, which comprises multiple resistor modules connected by relays. The relays switch the series and parallel connection of the resistor modules within the bridged resistor structure. Specifically, the multiple resistor modules include resistor module A1, resistor module A2, resistor module A3, resistor module A4, resistor module A5, and resistor module A6. Resistor modules A1, A2, A3, A4, A5, and A6 are connected by several relays. Switching the on / off state of the relays in the bridged resistor structure switches the series and parallel connection of the resistor modules.

[0048] More specifically, resistor module A1 includes: resistors R1, R2, and R3 connected in series; the connection point between resistors R1 and R2, the connection point between resistors R2 and R3, and the other end of resistor R3 are respectively connected to one end of adjusting potentiometer VR1 via relays K4A, K6A, and K5A, respectively; the other end of adjusting potentiometer VR1 is connected to relay K5A at the same point as the control terminal. Resistor module A2 includes: resistors R4, R5, and R6 connected in series; the input terminal of resistor R4 is connected to resistor R3 via relay K5A; the connection point between resistors R4 and R5, the connection point between resistors R5 and R6, and the other end of resistor R7 are respectively connected to relays K7A, K9A, and K5A, respectively. Resistor K8A is connected to one end of potentiometer VR2, and the other end of potentiometer VR2 is connected to relay K8A at the same point as the control terminal; Resistor module three A3 includes: resistors R7, R8, and R9 connected in series; the input terminal of resistor R7 is connected to resistor R6 via relay K8A; the connection point of resistors R7 and R8, the connection point of resistors R8 and R9, and the other end of resistor R9 are respectively connected to one end of potentiometer VR3 via relays K10A, K12A, and K11A, and the other end of potentiometer VR3 is connected to the control terminal at the same point; Resistor module four A4 includes: resistors R10, R11, and R12 connected in series; the connection point of resistors R10 and R11, the other end of resistor VR3 is connected to relay K10A, K12A, and K11A at the same point as the control terminal; The connection point of resistors R11 and R12, and the other end of resistor R12 are respectively connected to one end of potentiometer VR4 via relays K19A, K21A, and K20A. The other end of potentiometer VR4 is connected to relay K20A at the same point as the control terminal. Resistor module five A5 includes: resistors R13, R14, and R15 connected in series. The input terminal of resistor R13 is connected to resistor R12 via relay K21A. The connection point of resistors R13 and R14, the connection point of resistors R14 and R15, and the other end of resistor R15 are respectively connected to one end of potentiometer VR5 via relays K22A, K24A, and K23A. The other end is connected to relay K23A at the same point as the control terminal; resistor module six A6 includes: resistors R16, R17, and R18 connected in series; the input terminal of resistor R16 is connected to resistor R15 through relay K23A; the connection point of resistors R16 and R17, the connection point of resistors R17 and R18, and the other end of resistor R18 are respectively connected to one end of adjusting potentiometer VR6 through relays K25A, relay K27A, and relay K26A, and the other end of adjusting potentiometer VR6 is connected to relay K26A at the same point as the control terminal; the common connection point of relays K4A, K6A, and K5A is connected to the common connection point of relays K19A, K21A, and K20A;The common connection point of relays K7A, K9A, and K8A is connected to the common connection point of relays K22A, K24A, and K23A; the common connection point of relays K10A, K12A, and K11A is connected to the common connection point of relays K25A, K27A, and K26A; the input terminal of resistor R1 is connected to the input terminal of resistor R10 through relays K3A and K18A connected in series; the input terminal of resistor R4 is connected to the input terminal of resistor R13 through relays K2A and K17A connected in series; the input terminal of resistor R7 is connected to the input terminal of resistor R16 through relays K1A and K16A connected in series; the common connection point of relays K3A and K18A, relays K2A and K17A, and relays K1A and K16A serves as output terminal A. The control terminal of potentiometer VR3 is connected to one end of relay K13A; the control terminal of potentiometer VR6 is connected to one end of relay K30A; the other ends of relays K13A and K30A are connected together; the other end of relay K2A is connected to the input terminal of resistor R4, and a branch is connected to one end of relay K15A; the other end of relay K1A is connected to the input terminal of resistor R7, and a branch is connected to one end of relay K14A; the other end of relay K17A is connected to the input terminal of resistor R13, and a branch is connected to one end of relay K28A; the other end of relay K16A is connected to the input terminal of resistor R13, and a branch is connected to one end of relay K29A. The other ends of relays K14A, K15A, K28A, and K29A are connected at a common point to the connection node of relays K13A and K30A.

[0049] More specifically, the FPGA module receives operation commands from user interface 1 through the UART communication module. The FPGA module then outputs control signals through the GPIO interface to drive Darlington transistors to control the series and parallel connection of resistor modules in the programmable resistor module.

[0050] More specifically, the ADC data acquisition module 3 includes an ADC data acquisition chip; the ADC data acquisition chip is connected to the programmable resistor module through the SMU module 2, and is used to acquire the FPGA control signals sent by the FPGA module to the programmable resistor module; the acquisition end of the ADC data acquisition chip is connected to a multimeter to acquire the measurement results of the multimeter.

[0051] More specifically, the FPGA module is connected to the relays in the programmable resistor module via Darlington transistors to drive the relays' switching on and off, enabling the series and parallel connection of resistors within the programmable resistor module. The Darlington transistor includes transistor Q1. The base of transistor Q1 is connected to the FPGA module via resistor R71. The base of transistor Q1 is connected to its emitter via resistor R72. Resistor R72 is also connected to the emitter of transistor Q2 via resistor R73. The junction of resistors R72 and R73 is connected to the emitter of transistor Q1, and the emitter of transistor Q2 is grounded. The collectors of transistors Q1 and Q2 are connected and serve as the OUT output terminal. Furthermore, the junction of these two terminals also branches off into a COM terminal via diode D1, which is connected to the programmable resistor module via the OUT output terminal. Furthermore, when a Darlington transistor drives a relay, the COM terminal is primarily used to connect to the power supply. When the Darlington transistor drives a relay, the COM terminal can be connected to the positive terminal of the power supply to provide the drive current; the OUT terminal is used to connect to the corresponding relay in the programmable resistor module. When the input terminal of the Darlington transistor receives a control signal, the OUT terminal will output a corresponding current to drive the relay in the programmable resistor module.

[0052] Furthermore, series connection: When multiple resistor modules are connected in series, the total resistance is the sum of the resistances of each individual module. For example, if the resistances of resistor modules A1, A2, A3, A4, A5, and A6 are RA1, RA2, RA3, RA4, RA5, and RA6 respectively, then the total resistance after series connection is: R 总 =RA1+RA2+RA3+RA4+RA5+RA6.

[0053] Parallel Connection: When multiple resistor modules are connected in parallel, the reciprocal of the total resistance is the sum of the reciprocals of the resistances of each individual module. For example, if resistor modules A1, A2, A3, A4, A5, and A6 have resistances RA1, RA2, RA3, RA4, RA5, and RA6 respectively, then the total resistance after parallel connection is: R 总 =1 / (RA1+RA2+RA3+RA4+RA5+RA6).

[0054] By using different series and parallel combinations, the desired total resistance value can be obtained, and the accuracy of the module resistors can be finely adjusted as needed. The ADC data acquisition module 3 monitors the current and voltage and records all measurement results. Verification tests are performed to confirm the validity and accuracy of the data.

[0055] In this embodiment, the potentiometer inside each module can adjust the resistance value of that module, precisely controlling the resistance of the entire circuit. The resistance value can be adjusted according to different operating conditions without replacing the resistive components. For example, if the resistance values ​​of some modules deviate significantly, it can be corrected by adjusting potentiometers VR1~VR6. The FPGA connects to the digital potentiometers via an SPI interface, and the FPGA control logic adjusts the digital potentiometer values ​​based on feedback from the ADC data acquisition module.

[0056] Modular Design: This series-bridged resistor structure features a highly modular design. If adjustments are insufficient to meet requirements, multiple resistor modules can be stacked to achieve modular stacking. Each resistor module can be used independently or combined with other modules in series or parallel to adapt to different circuit configurations and needs.

[0057] Standalone use: When only a simple resistance value is needed, a single resistor module can be selected for standalone use, saving space and reducing costs.

[0058] Combined use: By combining multiple resistor modules into more complex circuits, a wider range of resistor options can be obtained to meet more complex circuit design requirements. For example, connecting resistor module A1 in series with resistor modules A2 and A3, and then connecting it in parallel with resistor modules A4, A5, and A6, can satisfy circuit designs that require multiple different resistance values.

[0059] Modular design also means that if a resistor module fails, only that module can be replaced instead of the entire circuit, thus reducing maintenance costs and downtime.

[0060] Working principle:

[0061] like Figures 1-5 As shown, an efficient and accurate automatic SMU calibration system is presented; it can adjust and compensate for measurement errors, improving the reliability of test results. The automatic SMU calibration system aims to improve measurement accuracy and consistency, reduce human error, increase testing efficiency, and ensure that the equipment maintains optimal performance in complex experimental environments. This system can automatically adjust and compensate for various measurement errors, ultimately achieving more reliable test results.

[0062] The UART communication module is configured for data communication between the user interface and the programmable resistor box. The control unit receives commands from the UART communication module to control the precision resistor module, performing automatic measurements and calibrating the SMU's output voltage and current. The series-bridged resistor structure, composed of multiple precision resistor modules, enables high-precision current and voltage measurements and has the ability to dynamically adjust resistance values, ensuring calibration stability under different load conditions. The control unit receives user operation commands and controls the precision resistor module for automatic testing. The programmable resistor box consists of multiple high-precision resistor elements arranged in a series-bridged structure to meet various measurement needs. The user interface sends commands via the UART communication module to control the programmable resistor box for automatic measurements. Example 3

[0063] Based on Embodiment 2, the operation can be made more intuitive and the threshold for use can be lowered by adopting the human-computer interaction interface in the prior art and introducing the user-friendly interface design in the prior art. Example 4

[0064] Based on Example 2, such as Figures 1-5 As shown, potentiometers VR1, VR2, VR3, VR4, VR5, and VR6 are all digital potentiometers, and the control terminals of the digital potentiometers are connected to the FPGA module.

[0065] Working principle:

[0066] like Figures 1-5 As shown, an efficient and accurate automatic SMU calibration system is presented; it can adjust and compensate for measurement errors, improving the reliability of test results. The automatic SMU calibration system aims to improve measurement accuracy and consistency, reduce human error, increase testing efficiency, and ensure that the equipment maintains optimal performance in complex experimental environments. This system can automatically adjust and compensate for various measurement errors, ultimately achieving more reliable test results.

[0067] The UART communication module is configured for data communication between the user interface and the programmable resistor box. The control unit receives commands from the UART communication module to control the precision resistor module, performing automatic measurements and calibrating the SMU's output voltage and current. The series-bridged resistor structure, composed of multiple precision resistor modules, enables high-precision current and voltage measurements and has the ability to dynamically adjust resistance values, ensuring calibration stability under different load conditions. The control unit receives user operation commands and controls the precision resistor module for automatic testing. The programmable resistor box consists of multiple high-precision resistor elements arranged in a series-bridged structure to meet various measurement needs. The user interface sends commands via the UART communication module to control the programmable resistor box for automatic measurements.

[0068] This invention discloses an automatic SMU calibration system, in which a programmable resistor box houses a control unit, a series-bridged resistor structure, and a high-frequency UART communication module. Multiple resistors with the same or different resistance values ​​are connected in series to form resistor modules A1, A2, A3, A4, A5, A6…An. Each different resistor module can be connected in series or parallel to freely form one or more bridged resistor networks. Each resistor module contains an adjustment potentiometer, which can adjust the precision of a single resistor element or the entire resistor module. Higher measurement accuracy is achieved through a reasonable bridging resistor configuration and graded adjustment of each module. The programmable resistor box can be connected to a high-precision multimeter to monitor test data in real time and transmit test data to a user interface via USB connection. The user interface sends relevant commands through the UART communication module to control the programmable resistor box, automatically measuring and calibrating the voltage and current output by the source measurement unit (SMU). The SMU's ADC data acquisition module receives the calibration results, processes the data, and transmits the processed calibration results to the user interface for monitoring and data recording. This invention effectively improves the calibration efficiency of SMUs, reduces manual intervention, and enhances test accuracy, meeting the demands of modern semiconductor testing for speed and efficiency. Through automated calibration, manual intervention is significantly reduced, increasing calibration speed and efficiency. The system can adjust and correct SMU outputs in real time, ensuring the accuracy of test results. It can be configured to meet different testing needs, adapting to various types of SMUs and testing scenarios.

[0069] Based on the preferred embodiments of this utility model, and through the above description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the claims.

Claims

1. An automatic calibration system for an SMU, characterized in that, include: The programmable resistor module (4) includes a UART communication module, which is connected to the programmable resistor module through a control unit. The programmable resistor module is connected to the user interface (1) and the ADC data acquisition module (3) through a multimeter (5). The ADC data acquisition module (3) feeds back data to the user interface (1), and the user interface (1) sends data to the UART communication module. The ADC data acquisition module is connected to the programmable resistor module through an SMU module (2).

2. The SMU automatic calibration system according to claim 1, characterized in that: The programmable resistor module (4) also includes a power supply circuit for supplying power to the UART communication module and the control unit. The UART communication module includes a communication chip and a communication interface, and the control unit includes an FPGA module; the communication chip is connected to the power supply circuit through the communication interface, and the communication chip is also connected to the FPGA module, which is connected to a programmable resistor module.

3. The SMU automatic calibration system according to claim 2, characterized in that: The programmable resistor module includes a bridged resistor structure, which comprises multiple resistor modules connected by relays. The relays switch the series and parallel connections of the resistor modules in the bridged resistor structure.

4. The SMU automatic calibration system according to claim 3, characterized in that: Multiple resistor modules include resistor module one (A1), resistor module two (A2), resistor module three (A3), resistor module four (A4), resistor module five (A5), and resistor module six (A6). Resistor module one (A1), resistor module two (A2), resistor module three (A3), resistor module four (A4), resistor module five (A5), and resistor module six (A6) are connected through several relays. By switching the on and off of the relays in the bridged resistor structure, the series and parallel connection of the resistor modules can be switched.

5. The SMU automatic calibration system according to claim 4, characterized in that: Resistor module one (A1) includes: resistors R1, R2, and R3 connected in series; the connection node between resistors R1 and R2, the connection node between resistors R2 and R3, and the other end of resistor R3 are respectively connected to one end of adjusting potentiometer VR1 through relays K4A, K6A, and K5A, and the other end of adjusting potentiometer VR1 is connected to relay K5A at the same point as the control terminal; Resistor module two (A2) includes: resistors R4, R5, and R6 connected in series; the input terminal of resistor R4 is connected to resistor R3 via relay K5A; the connection point of resistors R4 and R5, the connection point of resistors R5 and R6, and the other end of resistor R7 are respectively connected to one end of adjusting potentiometer VR2 via relays K7A, K9A, and K8A; the other end of adjusting potentiometer VR2 is connected to relay K8A at the same point as the control terminal. Resistor module three (A3) includes: resistors R7, R8, and R9 connected in series; the input terminal of resistor R7 is connected to resistor R6 via relay K8A; the connection point of resistors R7 and R8, the connection point of resistors R8 and R9, and the other end of resistor R9 are respectively connected to one end of adjusting potentiometer VR3 via relays K10A, K12A, and K11A, and the other end of adjusting potentiometer VR3 is connected to the control terminal at the same point; Resistor module four (A4) includes: resistors R10, R11, and R12 connected in series; the connection node between resistors R10 and R11, the connection node between resistors R11 and R12, and the other end of resistor R12 is connected to one end of adjusting potentiometer VR4 through relays K19A, K21A, and K20A respectively. The other end of adjusting potentiometer VR4 is connected to relay K20A at the same point as the control terminal. Resistor module five (A5) includes: resistors R13, R14, and R15 connected in series; the input terminal of resistor R13 is connected to resistor R12 via relay K21A; the connection point of resistors R13 and R14, the connection point of resistors R14 and R15, and the other end of resistor R15 are respectively connected to one end of adjusting potentiometer VR5 via relays K22A, K24A, and K23A; the other end of adjusting potentiometer VR5 is connected to relay K23A at the same point as the control terminal. Resistor module six (A6) includes: resistors R16, R17, and R18 connected in series; the input terminal of resistor R16 is connected to resistor R15 via relay K23A; the connection point of resistors R16 and R17, the connection point of resistors R17 and R18, and the other end of resistor R18 are respectively connected to one end of adjusting potentiometer VR6 via relays K25A, K27A, and K26A; the other end of adjusting potentiometer VR6 is connected to relay K26A at the same point as the control terminal. The common connection point of relays K4A, K6A, and K5A is connected to the common connection point of relays K19A, K21A, and K20A; the common connection point of relays K7A, K9A, and K8A is connected to the common connection point of relays K22A, K24A, and K23A; the common connection point of relays K10A, K12A, and K11A is connected to the common connection point of relays K25A, K27A, and K26A. The input terminal of resistor R1 is connected to the input terminal of resistor R10 through relays K3A and K18A connected in series. The input terminal of resistor R4 is connected to the input terminal of resistor R13 through relays K2A and K17A connected in series. The input terminal of resistor R7 is connected to the input terminal of resistor R16 through relays K1A and K16A connected in series. The connection nodes of relays K3A and K18A, K2A and K17A, and K1A and K16A share a common point as output terminal A. The control terminal of potentiometer VR3 is connected to one end of relay K13A; the control terminal of potentiometer VR6 is connected to one end of relay K30A; the other end of relay K13A is connected to the other end of relay K30A; the other end of relay K2A is connected to the input terminal of resistor R4, and a branch is connected to one end of relay K15A; the other end of relay K1A is connected to the input terminal of resistor R7, and a branch is connected to one end of relay K14A; the other end of relay K17A is connected to the input terminal of resistor R13, and a branch is connected to one end of relay K28A; the other end of relay K16A is connected to the input terminal of resistor R13, and a branch is connected to one end of relay K29A; and the other ends of relays K14A, K15A, K28A, and K29A are connected at a common point to the connection node of relays K13A and K30A.

6. The SMU automatic calibration system according to claim 2, characterized in that: The FPGA module receives operation instructions from the user interface (1) through the UART communication module. The FPGA module outputs control signals through the GPIO interface to drive the Darlington transistor to control the series and parallel connection of the resistor modules in the programmable resistor module.

7. The SMU automatic calibration system according to claim 5, characterized in that: The ADC data acquisition module (3) includes an ADC data acquisition chip; the ADC data acquisition chip is connected to the programmable resistor module through the SMU module (2) and is used to acquire the FPGA control signal sent by the FPGA module to the programmable resistor module; the acquisition end of the ADC data acquisition chip is connected to a multimeter to acquire the measurement results of the multimeter.

8. An SMU automatic calibration system according to claim 6, characterized in that: The FPGA module is connected to the relay in the programmable resistor module through a Darlington transistor, which is used to drive the relay in the programmable resistor module to switch on and off, and to realize the series and parallel connection of the resistor modules in the programmable resistor module. The Darlington transistor includes transistor Q1. The base of transistor Q1 is connected to the FPGA module through resistor R71. The base of transistor Q1 is connected to the emitter of transistor Q1 through resistor R72. Resistor R72 is also connected to the emitter of transistor Q2 through resistor R73. The connection point of resistors R72 and R73 is connected to the emitter of transistor Q1. The emitter of transistor Q2 is grounded. The collector of transistor Q1 is connected to the collector of transistor Q2 and serves as the OUT output terminal. The connection point of the collectors of transistor Q1 and Q2 also branches off to a diode D1 as the COM terminal. The OUT output terminal is connected to the programmable resistor module.

9. An SMU automatic calibration system according to claim 5, characterized in that: The adjustable potentiometers VR1, VR2, VR3, VR4, VR5, and VR6 are all digital potentiometers, and the control terminals of the digital potentiometers are connected to the FPGA module.

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