A scanning electron microscope in-situ heating and electrical testing apparatus and method

Abstract

This invention provides an in-situ heating and electrical testing apparatus and method for scanning electron microscopy (SEM). The apparatus includes a T-shaped sample stage, an in-situ heating and electrical testing chip, a probe card, wires, a vacuum flange with a BNC interface, a signal source meter, pins, and fixing studs. The in-situ heating and electrical testing chip is placed on the T-shaped sample. The probe card presses into contact with the heating and testing electrodes on the in-situ heating and electrical testing chip and leads out wires, simultaneously fixing the chip. The fixing studs secure the probe card to the T-shaped sample stage. The vacuum flange with the BNC interface connects the probe card and the signal source meter via wires. This invention provides in-situ heating, electrical testing, and microstructure observation functions for SEM, offering advantages such as rapid heating and cooling, low thermal drift, and low electromagnetic interference. It provides a platform for testing the performance of micro and nanomaterials and an experimental platform for preliminary screening of transmission electron microscopy (TEM) samples.

Description

Technical Field

[0001] This invention belongs to the field of in-situ characterization of material microstructure and properties, specifically relating to a scanning electron microscope in-situ heating and electrical testing device and method. Background Technology

[0002] With the development of science and technology, micro and nanomaterials are widely used in various fields. As the feature size of materials is reduced to the micro and nano scale, the material properties exhibit significant size effects. The structure and properties of micro and nanomaterials evolve differently under different physical fields and external environments. Therefore, in-situ microstructure and property testing platforms are needed.

[0003] In-situ electron microscopy (ESM) allows for dynamic studies of the microstructure and property evolution of materials under multiple physics fields. Currently, the main techniques used are transmission electron microscopy (TEM) in-situ sample holders and scanning electron microscopy (SEM) in-situ sample stages.

[0004] In the field of heating and electrical testing of micro and nanomaterials, the in-situ heating rod of transmission electron microscopy is a device for in-situ characterization of nanoparticles, but it is expensive in terms of time and consumables. For in-situ research on heating and electrical testing of materials at the scale of hundreds of nanometers and above, the in-situ sample stage of scanning electron microscopy is mainly relied upon.

[0005] Existing in-situ sample stages for scanning electron microscopes mainly employ electric heating devices and cooling water, which suffer from problems such as large sample stages, significant electromagnetic interference, and severe thermal drift. To address these issues, an in-situ heating and electrical testing device for scanning electron microscopes is proposed. This device boasts advantages such as small size, low electromagnetic interference, and low thermal drift, meeting the application requirements for studying the electrical properties of submicron and micron materials under different temperature fields, while also satisfying the needs of sample screening for transmission electron microscopes. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an in-situ heating and electrical testing apparatus and method for scanning electron microscopy (SEM). The apparatus includes an in-situ heating electrical testing chip, a sample stage, a probe card, a vacuum flange, a signal generator, and a control program. This apparatus provides in-situ heating, electrical testing, and microstructure observation functions for SEM, offering advantages such as rapid heating and cooling, low thermal drift, and low electromagnetic interference. It provides a platform for testing the performance of micro / nano materials and for preliminary screening of transmission electron microscopy (TEM) samples.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A scanning electron microscope (SEM) in-situ heating and electrical testing device includes a T-shaped sample stage, an in-situ heating and electrical testing chip, a probe card, wires, a vacuum flange with a BNC interface, a signal source meter, and a fixing stud. The in-situ heating and electrical testing chip is placed on the T-shaped sample stage. The probe card presses into contact with the heating electrode and test electrode on the in-situ heating and electrical testing chip and leads out wires. The fixing stud fixes the probe card to the T-shaped sample stage. The vacuum flange with a BNC interface connects the probe card and the signal source meter through wires.

[0009] Furthermore, the in-situ heating and electrical testing chip also includes a silicon wafer, silicon nitride, silicon oxide, an observation window, and a suspended area. The silicon nitride on the silicon wafer serves as a mechanical support layer. The heating electrode and the test electrode are disposed on the mechanical support layer, forming an in-situ heating and electrical testing area. The observation window is located in the center of the in-situ heating and electrical testing area. The silicon oxide serves as a passivation layer above the heating electrode and the test electrode. The suspended area extends through the silicon wafer and the silicon nitride, with the observation window corresponding to the area above the suspended area.

[0010] Furthermore, the T-shaped sample stage is made of aluminum alloy.

[0011] Furthermore, the vacuum flange with BNC interface includes a vacuum flange and six BNC terminals.

[0012] Furthermore, the signal source meter provides and tests voltage and current, and its setting control program controls signal output and testing.

[0013] The present invention also provides a testing method for an in-situ heating and electrical testing device for a scanning electron microscope, comprising the following steps:

[0014] Step 1: Check that all components are intact and that there are no open circuits in the circuit connections;

[0015] Step 2: Place the sample onto the in-situ heating and electrical testing chip by means of brush transfer or dispersion, and place and fix the in-situ heating and electrical testing chip into the chip slot on the T-shaped sample stage;

[0016] Step 3: Place and fix the probe card into the corresponding slot on the T-shaped sample, and ensure that the probe is in contact with and connected to the heating electrode and test electrode on the in-situ heating and electrical test chip.

[0017] Step 4: Connect the probe card to the BNC port on the vacuum flange with the BNC interface using wires, connect the BNC port to the wiring port of the signal source meter, apply a current of 0.1-2mA through the control program and test the resistance to confirm the continuity of the entire test circuit.

[0018] Step 5: Close the chamber door of the scanning electron microscope and evacuate the vacuum.

[0019] Step six: After the scanning electron microscope reaches the working state under vacuum, the test experiment begins. The sample is heated and its electrical properties are tested through the control program, and the microscopic changes of the sample are observed through the scanning electron microscope.

[0020] Step 7: After completing the test, open the chamber door of the scanning electron microscope, remove the T-shaped sample stage, and restore the vacuum in the chamber of the scanning electron microscope.

[0021] Beneficial effects:

[0022] The scanning electron microscope (SEM) in-situ heating and electrical testing chip designed and fabricated in this invention can achieve micro-area heating and cooling with low power consumption and low electromagnetic interference. Due to its unique structural layer design, this chip enables rapid heating and cooling while maintaining good structural stability and low thermal drift. Compared to TEM in-situ heating devices, it provides a new platform for testing the performance of submicron and micron-level samples, offering an experimental platform for sample screening. This invention features low thermal drift, low electromagnetic interference, rapid heating and cooling, and the ability to perform in-situ heating and electrical testing, meeting the research requirements for in-situ heating and electrical testing of micro and nanomaterials. The in-situ heating and electrical testing device based on a scanning electron microscope (SEM) involved in this invention can achieve high-temperature experimental research up to 650 degrees Celsius. Attached Figure Description

[0023] Figure 1 This is an overall view of a scanning electron microscope in-situ heating and electrical testing device provided in an embodiment of the present invention;

[0024] Figure 2 This is a top view of the sample stage provided in an embodiment of the present invention;

[0025] Figure 3 This is a cross-sectional view of the in-situ heating and electrical testing chip provided in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the in-situ heating and electrical testing chip provided in an embodiment of the present invention;

[0027] Figure 5 This is an enlarged view of the core functional area of ​​the in-situ heating and electrical testing chip provided in this embodiment of the invention;

[0028] The components include: 1. T-shaped sample stage; 2. In-situ heating and electrical test chip; 3. Probe card; 4. Wires; 5. Vacuum flange with BNC interface; 6. Signal source meter; 7. Fixing stud; 2-1. Silicon wafer; 2-2. Silicon nitride; 2-3. Heating electrode; 2-4. Test electrode; 2-5. Silicon oxide; 2-6. Observation window; 2-7. Suspended area. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1 , Figure 2 As shown, a scanning electron microscope (SEM) in-situ heating and electrical testing device of the present invention includes a T-shaped sample stage 1, an in-situ heating and electrical testing chip 2, a probe card 3, wires 4, a vacuum flange 5 with a BNC interface, a signal source meter 6, a fixing stud 7, and a control program. The in-situ heating and electrical testing chip 2 is placed on the T-shaped sample stage 1; the probe card 3 presses against the heating electrode 2-3 and the test electrode 2-4 on the in-situ heating and electrical testing chip 2 and leads out the wires 4; the fixing stud 7 fixes the probe card 3 to the T-shaped sample stage 1; the vacuum flange 5 with a BNC interface connects the in-situ heating and electrical testing chip 2 and the signal source meter 6 via the wires 4. The T-shaped sample stage 1 is a sample stage compatible with the SEM, and combined with the in-situ heating and electrical testing chip 2, it enables heating and electrical characteristic testing in a small space. Applying the in-situ heating and electrical testing chip 2 to the SEM provides an in-situ experimental platform for the study of materials at the nanometer and micrometer levels.

[0031] like Figure 3 , Figure 4 , Figure 5 As shown, the in-situ heating and electrical testing chip 2 includes a silicon wafer (2-1), silicon nitride (2-2), heating electrode (2-3), testing electrode (2-4), silicon oxide (2-5), observation window (2-6), and suspended area (2-7), which are used to provide in-situ micro-area heating and electrical testing functions. The substrate of the in-situ heating and electrical testing chip 2 is a silicon wafer 2-1, with silicon nitride 2-2 serving as a mechanical support layer on the surface of the silicon wafer 2-1. Heating electrodes 2-3 and test electrodes 2-4 are disposed on the silicon nitride 2-2, with silicon oxide 2-5 serving as a passivation layer on the surfaces of the heating electrodes 2-3 and test electrodes 2-4. The heating electrodes 2-3 and test electrodes 2-4 surround each other to form an in-situ heating and electrical testing area. An observation window 2-6 is located in the center of this area and is used for in-situ characterization of micro-areas using scanning electron microscopy. A suspended region 2-7 extends between the silicon wafer 2-1 and the silicon nitride 2-2, providing thermal insulation. The upper surface of the suspended region 2-7 corresponds to the observation window 2-6. The in-situ heating and electrical testing chip 2 features rapid heating and cooling, low electromagnetic interference, and low thermal drift, thus achieving in-situ micro-area heating and electrical testing functions.

[0032] The vacuum flange 5 with BNC interface includes a vacuum flange and 6 BNC terminals. The vacuum flange 5 with BNC interface is connected to the probe card 3 and the signal source meter 6 via wire 4.

[0033] The signal source table 6 provides and tests voltage and current, and its signal output and testing are controlled by a control program.

[0034] The control program can control the output of the signal source meter and test voltage and current signals to achieve heating temperature control and electrical testing.

[0035] The testing method of the present invention includes the following steps:

[0036] Step 1: Check that all components are intact and that there are no open circuits in the circuit connections;

[0037] Step 2: The sample is placed on the in-situ heating and electrical testing chip 2 by means of brush transfer or dispersion, and the in-situ heating and electrical testing chip 2 is placed and fixed in the chip slot on the T-shaped sample stage 1.

[0038] Step 3: Place and fix the probe card 3 into the corresponding slot on the T-shaped sample stage 1, and ensure that the probe is in contact with and connected to the heating electrode 2-3 and the test electrode 2-4 on the in-situ heating and electrical test chip 2.

[0039] Step 4: Connect probe card 3 to the BNC port on vacuum flange 5 with BNC interface, connect the BNC port on vacuum flange 5 to the wiring port of signal source meter 6, apply 0.1-2mA current through the control program and test the resistance to determine the continuity of the entire test circuit.

[0040] Step 5: Close the chamber door of the scanning electron microscope and evacuate the vacuum.

[0041] Step six: After the scanning electron microscope reaches the working state under vacuum, the test experiment begins. The sample is heated and its electrical properties are tested through the control program, and the microscopic changes of the sample are observed through the scanning electron microscope.

[0042] Step 7: After completing the test, open the chamber door of the scanning electron microscope, remove the T-shaped sample stage, and restore the vacuum in the chamber of the scanning electron microscope.

[0043] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A scanning electron microscope in-situ heating and electrical testing device, characterized in that: The device includes a T-shaped sample stage, an in-situ heating and electrical test chip, a probe card, wires, a vacuum flange with a BNC interface, a signal source meter, and fixing studs. The in-situ heating and electrical test chip is placed on the T-shaped sample stage. The probe card presses into contact with the heating and test electrodes on the in-situ heating and electrical test chip and leads out wires. The fixing studs fix the probe card to the T-shaped sample stage. The vacuum flange with a BNC interface connects the probe card and the signal source meter via wires. The signal source meter provides and tests voltage and current, and its control program controls signal output and testing. The in-situ heating and electrical testing chip also includes a silicon wafer, silicon nitride, silicon oxide, an observation window, and a suspended area. The silicon nitride on the silicon wafer is a mechanical support layer. The heating electrode and the test electrode are disposed on the mechanical support layer and surround each other to form an in-situ heating and electrical testing area. The observation window is located in the center of the in-situ heating and electrical testing area. The silicon oxide is disposed above the heating electrode and the test electrode as a passivation layer. The suspended area runs through the silicon wafer and the silicon nitride, and the observation window is located above the suspended area. The structural layer design of the in-situ heating and electrical testing chip enables rapid heating and cooling, while also exhibiting good structural stability and low thermal drift, enabling high-temperature experimental research at 650 degrees Celsius. The electrodes of the core functional area of ​​the in-situ heating and electrical testing chip have two ends, and each end includes two heating electrodes and two testing electrodes. The two heating electrodes on the same end are arranged together in a ring, and their two external connection ends are spaced apart. At the same time, the two testing electrodes on the same end are respectively arranged outside the two heating electrodes and are arranged around them. The external connection ends of the four sets of opposite electrodes at both ends are evenly spaced circumferentially.

2. The scanning electron microscope in-situ heating and electrical testing device according to claim 1, characterized in that: The T-shaped sample stage is made of aluminum alloy.

3. The scanning electron microscope in-situ heating and electrical testing device according to claim 1, characterized in that: The vacuum flange with BNC interface includes a vacuum flange and six BNC terminals.

4. The testing method of the scanning electron microscope in-situ heating and electrical testing device according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Check that all components are intact and that there are no open circuits in the circuit connections; Step 2: Place the sample onto the in-situ heating and electrical testing chip by means of brush transfer or dispersion, and place and fix the in-situ heating and electrical testing chip into the chip slot on the T-shaped sample stage; Step 3: Place and fix the probe card into the corresponding slot on the T-shaped sample, and ensure that the probe is in contact with and connected to the heating electrode and test electrode on the in-situ heating and electrical test chip. Step 4: Connect the probe card to the BNC port on the vacuum flange with the BNC interface using wires, connect the BNC port to the wiring port of the signal source meter, apply a current of 0.1-2mA through the control program and test the resistance to confirm the continuity of the entire test circuit. Step 5: Close the chamber door of the scanning electron microscope and evacuate the vacuum. Step 6: After the scanning electron microscope reaches the working state of vacuum, the test experiment begins. The sample is heated and its electrical properties are tested through the control program, and the microscopic changes of the sample are observed through the scanning electron microscope. Step 7: After completing the test, open the chamber door of the scanning electron microscope, remove the T-shaped sample stage, and restore the vacuum in the chamber of the scanning electron microscope.

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