Temperature sensing and control system for TEM or SEM and control method thereof

Abstract

The invention discloses a temperature sensing and control system for a TEM or an SEM and a control method thereof, and the system comprises a temperature sensing and control chip which is electrically connected with an external collection and drive module; a back cavity is formed in the substrate, a supporting layer is arranged on the back cavity, and a slope structure is arranged on the periphery of the supporting layer; a temperature sensing unit and a temperature control unit are arranged on the substrate and the supporting layer; a plurality of observation windows are arranged on the supporting layer; an electrical bias unit is arranged on the periphery of the observation window; the free ends of the temperature sensing unit, the electrical bias unit and the temperature control unit are all provided with electrode pressure welding blocks. According to the invention, in an in-situ test scene in which electron beam irradiation and electrical bias coexist, the temperature of the sample can be monitored in real time and precisely regulated and controlled, temperature data can be synchronously output, and the microscopic morphology and structure evolution are ensured to be in one-to-one correspondence with the actual temperature of the sample.

Description

TECHNICAL FIELD

[0001] The present application relates to a temperature sensing and control system for TEM or SEM and a control method thereof, and belongs to the technical field of electron microscopic analysis. BACKGROUND

[0002] TEM (Transmission Electron Microscope) and SEM (Scanning Electron Microscope) are important tools for studying the microstructure of materials. With the development of materials science, the dependence of research objects on temperature environment during microscopic observation is increasing. For example, in the study of phase transition and grain growth of nanomaterials, the temperature change of the sample directly affects the accuracy and repeatability of experimental data.

[0003] However, the existing microscope sample stage still has the following problems in temperature control:

[0004] 1. Lack of real-time temperature monitoring: Traditional heating or refrigeration methods can only adjust the sample environment temperature, and cannot directly feedback the real temperature of the sample caused by current or electron beam irradiation.

[0005] 2. Temperature control and temperature measurement are separated: The existing technology usually uses a combination of heating chips and frozen sample rods or frozen electron microscopes to control the sample temperature, which has low integration and slow response speed.

[0006] 3. Electron beam effect is not fully considered: In TEM / SEM, the high-energy electron beam produces additional heating effect on the sample, resulting in inconsistency between the actual sample temperature and the set temperature, which further affects the scientific interpretation of the microscopic changes of the sample.

[0007] Therefore, there is an urgent need for an integrated system that can simultaneously realize real-time monitoring and accurate control of temperature under TEM / SEM conditions to ensure that the microscopic observation results correspond to the actual temperature of the sample. SUMMARY

[0008] Objective: In order to overcome the shortcomings in the prior art, the present application provides a temperature sensing and control system for TEM or SEM and a control method thereof, which can realize real-time monitoring and accurate control of sample temperature in the in-situ testing scene where electron beam irradiation and electrical bias coexist, and can output temperature data synchronously, ensuring that the microscopic morphology, structure evolution and actual sample temperature correspond one by one.

[0009] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present application is:

[0010] In a first aspect, a temperature sensing and control system for TEM or SEM is provided, which specifically comprises: a temperature sensing and control chip, which is electrically connected with an external acquisition and driving module.

[0011] The temperature sensing and control chip comprises a substrate, a back cavity is formed on the substrate, a support layer is arranged on the back cavity, and a slope structure is arranged on the periphery of the support layer.

[0012] A temperature sensing unit and a temperature control unit are arranged on the substrate and the support layer.

[0013] A plurality of observation windows are arranged on the support layer.

[0014] An electrical biasing unit is arranged on the periphery of the observation window.

[0015] The temperature sensing unit and the electrical biasing unit are arranged on the two sides of the temperature control unit respectively, and the free ends of the temperature sensing unit, the electrical biasing unit and the temperature control unit are provided with electrode pressure welding blocks.

[0016] Optionally, an isolation cavity is arranged on the support layer between the temperature sensing unit, the temperature control unit and the electrical biasing unit.

[0017] Optionally, the temperature sensing unit comprises a first thermocouple, a temperature sensing area and a first heat dissipation area, the first thermocouple comprises a first N-type thermoelectric arm and a first P-type thermoelectric arm, the support layer is provided with the temperature sensing area, the support layer, the slope structure and the substrate are provided with a first heat dissipation area opposite to the temperature sensing area, the first N-type thermoelectric arm and the first P-type thermoelectric arm are connected in series through the temperature sensing area and one end of the first heat dissipation area, and the other end of the first heat dissipation area is connected with the electrode pressure welding block.

[0018] Optionally, the temperature control unit comprises a second thermocouple, a temperature control area and a second heat dissipation area, the second thermocouple comprises a second N-type thermoelectric arm and a second P-type thermoelectric arm, the support layer is provided with the temperature control area, the support layer, the slope structure and the substrate are provided with a second heat dissipation area opposite to the temperature control area, the second N-type thermoelectric arm and the second P-type thermoelectric arm are connected in series through the temperature control area and one end of the second heat dissipation area, and the other end of the second heat dissipation area is connected with the electrode pressure welding block.

[0019] Optionally, the temperature control area is arranged between the temperature sensing area and the electrical biasing unit.

[0020] Optionally, the first thermocouple, the temperature sensing area, the second thermocouple, the temperature control area, the electrical biasing unit and the observation window are arranged above the back cavity.

[0021] Optionally, the external acquisition and driving module comprises an external driving module, a controller, and an external acquisition module, the external driving module is electrically connected with the electrical biasing unit and the temperature control unit, the external acquisition module is electrically connected with the temperature sensing unit, and the external driving module and the external acquisition module are electrically connected with the controller.

[0022] The external acquisition module is configured to receive the electrical signal collected by the temperature sensing unit and convert the electrical signal into temperature data, and transmit the temperature data to the controller.

[0023] The external driving module is configured to provide an electrical signal to the temperature control unit and the electrical biasing unit to adjust the temperature of the sample.

[0024] The controller is configured to compare the collected real-time temperature with a preset target temperature and generate a driving signal of the temperature control unit.

[0025] Optionally, the support layer is made of polyimide.

[0026] Optionally, the first thermocouple and the second thermocouple are made of bismuth telluride-based low-temperature thermoelectric material.

[0027] In a second aspect, a control method of a temperature sensing and control system for TEM or SEM is provided, and the specific steps include:

[0028] Step 1: The electron beam irradiates the sample, and the external driving module provides an electrical signal to the sample through the electrical biasing unit to form an electrical loop.

[0029] Step 2: The temperature sensing unit detects the temperature signal of the sample in real time and transmits the temperature signal to the external acquisition module.

[0030] Step 3: The external acquisition module receives the temperature signal and processes it to output the real-time temperature. The controller compares the real-time temperature with the target temperature.

[0031] Step 4: The external driving module adjusts the input electrical signal of the temperature control unit according to the comparison result to realize closed-loop regulation of the temperature of the sample.

[0032] Beneficial effects: The temperature sensing and control system for TEM or SEM and the control method thereof provided by the application include a temperature sensing and control chip and an external acquisition and driving module electrically connected with the temperature sensing and control chip. The temperature sensing and control chip includes a temperature sensing unit, a temperature control unit and an electrical biasing unit. The temperature sensing unit is used for detecting the temperature change of a sample caused by an electrical circuit and electron beam irradiation in real time, and outputting an electrical signal related to the temperature. The temperature control unit is used for regulating and controlling the temperature of the sample under the action of an external electrical signal. The electrical biasing unit is connected with the sample and an external circuit, and is used for providing an electrical signal to the sample to realize electrical biasing or functional testing. The external acquisition and driving module can acquire the electrical signal transmitted by the chip and convert the electrical signal into temperature data, and output an adjustment electrical signal after comparison with a target temperature, so as to close-loop control the actual temperature of the sample, thereby realizing decoupling and stable control of the temperature of the sample and the temperature rise caused by the electron beam and the electrical circuit. Compared with the prior art, the application has the following beneficial effects:

[0033] (1) In-situ precise temperature control

[0034] The temperature sensing unit and the temperature control unit are arranged in the vicinity of the sample in cooperation, and are driven in a closed loop by an external controller, so as to realize real-time and precise temperature control under the condition that the electron beam irradiation and electrical biasing coexist. Compared with the scheme of relying on cavity or stage temperature control, the thermal hysteresis and temperature gradient are significantly reduced, the temperature response is faster, and the control precision is higher.

[0035] (2) Two-way temperature regulation capability

[0036] The temperature control unit supports two-way heating and refrigeration, which can not only compensate for overheating caused by the electron beam and Joule heat, but also provide active temperature control, and the temperature control range and application scenarios are wider.

[0037] (3) Temperature-electricity decoupling and synchronization

[0038] The independent electrical regulation unit provides a bias voltage for the sample to form an electrical circuit, and the temperature sensing and control function and the electrical biasing function are decoupled. In the process of microscopic observation, a temperature curve is synchronously output, so that the microscopic change and the real-time temperature are one-to-one corresponding, and the reliability of machine analysis and data traceability are improved.

[0039] (4) TEM / SEM universal compatibility

[0040] An observation window is arranged to adapt to TEM, and a non-hollow optional structure for SEM is provided. The same chip platform covers two types of mainstream electron microscopy techniques, reduces the switching cost and time of the device.

[0041] (5) Friendly installation and connection

[0042] The sample is located at the observation window and connected with the electrical biasing unit at both ends, and the electrode pressure welding block is connected with the commonly used commercial sample rod and sample table to form thermal and electrical connection, so that clamping and wiring can be completed through a standard external interface, the assembly difficulty is reduced, and the experimental repeatability and throughput are improved. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of a temperature sensing and control system for TEM or SEM.

[0044] Figure 2 It is a structural schematic diagram of a temperature sensing and control chip.

[0045] Figure 3 It is a sectional view of the temperature sensing and control chip.

[0046] Figure 4 It is a partial enlarged schematic diagram of the temperature sensing and control chip applied to TEM.

[0047] Figure 5 It is a base structure diagram in the temperature sensing and control chip applied to TEM.

[0048] Figure 6 It is a schematic diagram of the structural layer and the observation window in the temperature sensing and control chip applied to TEM.

[0049] Figure 7 It is a schematic diagram of the base, the structural layer and the observation window in the temperature sensing and control chip applied to TEM.

[0050] Figure 8 It is a simulation diagram of the relationship between the temperature sensing unit output electrical signal and temperature change.

[0051] Figure 9 It is a simulation diagram of the relationship between the temperature control unit temperature and the input electrical signal.

[0052] The reference signs, 1, temperature sensing unit; 11, first thermocouple; 111, first N-type thermoelectric arm; 112, first P-type thermoelectric arm; 12, temperature sensing area; 13, first heat dissipation area; 2, temperature control unit; 21, second thermocouple; 211, second N-type thermoelectric arm; 212, second P-type thermoelectric arm; 22, temperature control area; 23, second heat dissipation area; 3, electrical biasing unit; 4, electrode pressure welding block; 5, observation window; 6, sample; 7, structural layer; 71, support layer; 72, slope structure; 73, isolation cavity; 8, base; 81, substrate; 82, back cavity. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0054] The present application will be further described below in combination with specific embodiments.

[0055] Embodiment 1

[0056] This embodiment introduces a temperature sensing and control system for TEM or SEM, as shown in Figure 1 , specifically comprising: a temperature sensing and control chip, which is electrically connected with an external acquisition and driving module.

[0057] The temperature sensing and control chip, as shown in Figure 2 , Figure 3 , comprises: a substrate 8, which comprises a substrate 81, a back cavity 82 is opened on the substrate 81, a structure layer 7 is arranged on the back cavity 82, the structure layer 7 comprises a support layer 71, and a slope structure 72 is arranged on the periphery of the support layer 71.

[0058] The substrate 81 and the support layer 71 are provided with a temperature sensing unit 1 and a temperature control unit 2.

[0059] The support layer 71 is provided with a plurality of observation windows 5.

[0060] The periphery of the observation window 5 is provided with an electrical biasing unit 3.

[0061] The temperature sensing unit 1 and the electrical biasing unit 3 are respectively arranged on the two sides of the temperature control unit 2. The free ends of the temperature sensing unit 1, the electrical biasing unit 3 and the temperature control unit 2 are all provided with electrode pressure welding blocks 4.

[0062] Further, the support layer 71 between the temperature sensing unit 1, the temperature control unit 2 and the electrical biasing unit 3 is provided with an isolation cavity 73.

[0063] Further, the temperature sensing unit 1 comprises: a first thermocouple 11, a temperature sensing area 12, and a first heat dissipation area 13. The first thermocouple 11 comprises: a first N-type thermoelectric arm 111 and a first P-type thermoelectric arm 112. The temperature sensing area 12 is arranged on the support layer 71. The support layer 71, the slope structure 72, and the substrate 81 are provided with the first heat dissipation area 13 opposite to the temperature sensing area 12. The first N-type thermoelectric arm 111 and the first P-type thermoelectric arm 112 are connected in series between one end of the temperature sensing area 12 and one end of the first heat dissipation area 13. The other end of the first heat dissipation area 13 is connected to the electrode pressure welding block 4.

[0064] Further, the temperature control unit 2 comprises: a second thermocouple 21, a temperature control area 22, and a second heat dissipation area 23. The second thermocouple 21 comprises: a second N-type thermoelectric arm 211 and a second P-type thermoelectric arm 212. The temperature control area 22 is arranged on the support layer 71. The support layer 71, the slope structure 72, and the substrate 81 are provided with the second heat dissipation area 23 opposite to the temperature control area 22. The second N-type thermoelectric arm 211 and the second P-type thermoelectric arm 212 are connected in series between the temperature control area 22 and one end of the second heat dissipation area 23. The other end of the second heat dissipation area 23 is connected to the electrode pressure welding block 4.

[0065] Further, the temperature control area 22 is arranged between the temperature sensing area 12 and the electrical biasing unit 3.

[0066] Further, the first thermocouple 11, the temperature sensing area 12, the second thermocouple 21, the temperature control area 22, the electrical biasing unit 3, and the observation window 5 are all arranged above the back cavity 82.

[0067] Further, the external acquisition and driving module comprises: an external driving module, a controller, and an external acquisition module. The external driving module is electrically connected to the electrical biasing unit and the temperature control unit. The external acquisition module is electrically connected to the temperature sensing unit. The external driving module and the external acquisition module are electrically connected to the controller.

[0068] The external acquisition module is configured to receive the temperature data converted from the electrical signal collected by the temperature sensing unit and transmit the temperature data to the controller.

[0069] The external driving module is configured to provide electrical signals to the temperature control unit and the electrical biasing unit to adjust the temperature of the sample.

[0070] The controller is configured to compare the collected real-time temperature with a preset target temperature and generate a driving signal for the temperature control unit.

[0071] Embodiment 2:

[0072] The embodiment introduces the working principle of a temperature sensing and control system for TEM or SEM, wherein the temperature sensing and control chip comprises a substrate 8, a structure layer 7 (containing a support layer 71, a slope structure 72 and an isolation cavity 73), an observation window 5, an electrode pressure welding block 4, and a temperature sensing unit 1, a temperature control unit 2 and an electrical biasing unit 3 constructed on the layer system. A sample 6 is arranged at the observation window 5 and electrically connected with the electrical biasing unit 3; the electrical biasing unit 3 and the temperature sensing unit 1 are distributed on both sides of the temperature control unit 2.

[0073] The back of the substrate 8 is provided with a back cavity 82, which is arranged at the first thermocouple 11 and the temperature sensing area 12 of the temperature sensing unit 1, the second thermocouple 21 and the temperature control area 22 of the temperature control unit 2, and the sample observation window 5 of the electrical biasing unit 3, so that the above-mentioned areas are located above the support layer 71, and the heat dissipation areas of the temperature sensing unit 1 and the temperature control unit 2 and the non-observation window of the electrical biasing unit 3 are kept with the support layer 71 below, so as to provide mechanical support and heat dissipation channels. The back cavity 82 is prepared by photolithography and deep reactive ion etching process, which functions to isolate heat and reduce heat loss through the substrate 8, thereby improving the temperature measurement and control efficiency of the chip.

[0074] The structure layer 7 is located above the substrate 8, preferably made of an organic polymer material such as polyimide (PI), formed by spin coating and curing, which has good thermal insulation and mechanical flexibility. The structure layer 7 is patterned by a reactive ion etching (RIE) process, forming three key structures, namely the observation window 5, the slope structure 72 and the isolation cavity 73.

[0075] The observation window 5 is located at one end of the electrical biasing unit 3 close to the temperature control area 22, designed as a hollow, penetrating through the support layer 71, and can be circular, rectangular or other irregular shapes, etc., to adapt to different sample requirements. This design makes the sample suspended above the observation window 5, to ensure that the sample can be directly penetrated by the electron beam while ensuring the formation of the electrical circuit. For SEM applications, the observation window 5 can be designed as a non-hollow design to meet different experimental requirements.

[0076] The slope structure 72 is located below the heat dissipation areas of the temperature sensing unit 1 and the temperature control unit 2 and the non-observation window 5 area of the electrical biasing unit 3, wherein the electrical biasing unit 3 adopts a metal lead structure, a photoresist with a thickness gradient is formed by adjusting parameters, and after etching transfer, the slope structure 72 presents a continuous slope. It is used to ensure that the heat dissipation area and the electrical biasing unit 3 can be smoothly transitioned from the support layer 71 to the substrate 81, effectively increasing the heat flow path and improving the thermoelectric conversion efficiency.

[0077] The isolation cavity 73 is a groove or cavity on the support layer 71, which is located between the temperature sensing unit 1, the temperature control unit 2 and the electrical biasing unit 3. The isolation cavity 73 further provides thermal isolation and reduces crosstalk between the units, thereby enhancing the temperature sensing sensitivity and the temperature control efficiency.

[0078] The electrode bump 4 is prepared on the surface of the substrate 8 by photolithography, thermal evaporation or magnetron sputtering process. The electrode bump 4 is located at the edge of the chip and has a large size, which is used to realize the electrical connection between the chip and the external circuit by wire bonding. In addition, the temperature sensing region 12 and the first heat dissipation region 13 of the temperature sensing unit 1, the temperature control region 22 and the second heat dissipation region 23 of the temperature control unit 2, and the electrode bump 4 and the electrical biasing unit 3 are prepared by the same microfabrication process step.

[0079] The temperature control unit 2 is prepared on the support layer 71 and located at the center of the back cavity 82 and closely arranged with the observation window 5. The temperature control unit 2 includes at least one pair of second thermocouples 21, a temperature control region 22 and a second heat dissipation region 23. Each pair of second thermocouples 21 includes a second N-type thermoelectric arm 211 and a second P-type thermoelectric arm 212, and multiple pairs of thermocouples 21 can be connected in series to form a multi-stage structure to enhance the output signal. The end close to the observation window 5 constitutes the temperature control region 22, and the end away from the observation window 5, i.e., the end close to the edge of the chip, is the second heat dissipation region 23 connected to the substrate 81 through the slope structure 72. The free end of the second heat dissipation region 23 is connected to the electrode bump 4.

[0080] The temperature sensing unit 1 is arranged opposite to the electrical biasing unit 3 on both sides of the temperature control region 22. The temperature sensing unit 1 has a similar structure to the temperature control unit 2 and also includes a first thermocouple 11 composed of a first N-type thermoelectric arm 111 and a first P-type thermoelectric arm 112. The end close to the temperature control region 22 constitutes the temperature sensing region 12, and the end away from the temperature control region 22 is connected to the first heat dissipation region 13. The free end of the first heat dissipation region 13 is connected to the electrode bump 4.

[0081] The electrical biasing unit 3 adopts a metal lead structure, and two metal leads are distributed on both sides of the observation window 5. One end of the metal lead exceeds the observation window 5 and is close to the temperature control region 22, and the other end is connected to the electrode bump 4. The sample 6 is fixed on the metal leads on both sides of the observation window 5 by metal bonding, deposition or transfer, so as to connect the sample 6 into the electrical circuit formed by the external driving module, the electrical biasing unit 3 and the sample 6 itself.

[0082] The temperature sensing unit 1 and the temperature control unit 2 each comprise a large-area metal layer, including a temperature sensing area or a temperature control area and a heat dissipation area. The metal is made of the same material system as the electrical biasing unit 3 and the electrode pressure welding block 4 and is prepared by the same microfabrication process step, thereby realizing integrated integration. This means that the large-area metal electrically acts as a conductive lead connecting the thermocouple structure and thermally plays the core function of the temperature sensing area 12, the temperature control area 22 and the heat dissipation area, respectively. This integrated design eliminates additional connection interfaces, reduces thermal resistance, and significantly improves the thermal response speed and temperature control efficiency of the device.

[0083] The temperature sensing and control chip includes a temperature sensing unit 1, a temperature control unit 2 and an electrical biasing unit 3. The temperature sensing unit 1 is used to detect the temperature change of the sample caused by the electrical circuit and electron beam irradiation in real time, and outputs an electrical signal related to the temperature. The temperature control unit 2 is used to control the temperature of the sample under the action of an external electrical signal. The electrical biasing unit 3 connects the sample 6 and the external circuit, and is used to provide an electrical signal to the sample 6 to realize electrical biasing or functional testing. The external acquisition and driving module can convert the electrical signal transmitted by the chip into temperature data, compare it with the target temperature, and output a regulating electrical signal, thereby controlling the actual temperature of the sample in a closed loop, so as to realize decoupling and stable control of the temperature rise of the sample caused by the electrical circuit and electron beam.

[0084] The temperature sensing unit 1 in the embodiment is used to monitor the temperature change of the sample caused by the electrical circuit and electron beam irradiation in real time. The unit works by the Peltier effect of the first thermocouple 11, and outputs an electrical signal related to the temperature by using the thermoelectric effect generated by the temperature difference. In order to effectively avoid the self-heating problem that may be caused by traditional thermistors, the application adopts a thermocouple structure to ensure accurate temperature detection. Each pair of first thermocouples 11 is composed of a first N-type thermoelectric arm 111 and a first P-type thermoelectric arm 112. When the temperature changes, the temperature difference between the two ends of the thermoelectric arm will generate an electrical signal proportional to the temperature change. A plurality of first thermocouples 11 in series or parallel can further improve the detection accuracy and response speed.

[0085] The temperature control unit 2 in the embodiment adjusts the temperature of the sample according to an external electrical signal. The unit controls the temperature by the Seebeck effect and the Peltier effect. Specifically, when the external electrical signal is applied to the temperature control unit 2, the current transmits heat through the thermoelectric material, causing a temperature difference between the two ends of the second thermocouple 21, thereby heating or cooling the temperature control area 22. The unit is also composed of a single-stage or multi-stage second thermocouple 21 structure, and uses bismuth telluride-based low-temperature thermoelectric materials, which are suitable for TEM / SEM experimental environments. The temperature control unit 2 and the temperature sensing unit 1 work together to form a closed-loop control system. When a temperature change is detected, the system will adjust the current input through feedback, thereby accurately adjusting the temperature.

[0086] The electrical biasing unit 3 in the embodiment is connected with the sample 6 and an external circuit, and is mainly used to provide an electrical signal to the sample 6 to form an electrical loop and realize electrical biasing or functional testing. The free end of the electrical biasing unit 3 is connected with an electrode pressure welding block 4, and the two ends of the sample 6 are connected with the electrical biasing unit 3 of the two metal lead structures, so as to ensure that a closed loop is formed between the sample 6 and the external circuit. Under the action of the electrical biasing unit 3, the sample 6 can be micro-characterized in real time and in situ. The temperature sensing unit 1, the temperature control unit 2 and the electrical biasing unit 3 are integrated on the same chip by micro-machining, so as to reduce thermal hysteresis and improve response speed.

[0087] In operation, the external driving module applies an electrical signal to the sample 6 through the electrical biasing unit 3 to generate Joule heat or electrical excitation in the sample 6. At the same time, the electrical biasing unit 3 cooperates with the temperature control unit 2 to allow synchronous electrical testing during temperature regulation, so as to realize decoupling of the temperature of the sample 6 and the temperature rise of the electrical loop.

[0088] In the embodiment, the external acquisition and driving module is electrically connected with the chip in TEM through the electrode pressure welding block 4 connected with the sample rod pin, and is electrically connected with the external circuit in SEM through the electrode pressure welding block 4 connected with the lead bonding. The external acquisition module includes a signal amplifier, an analog-to-digital converter (ADC) and a data processing unit, which are used to receive the electrical signal collected by the temperature sensing unit 1, convert the electrical signal into temperature data, and transmit the temperature data to a controller. The external driving module includes a digital-to-analog converter (DAC) and a power amplifier, which are used to provide an electrical signal to the temperature control unit 2 and the electrical biasing unit 3 to adjust the temperature of the sample. The controller compares the collected real-time temperature with a preset target temperature, and generates a driving signal of the temperature control unit 2 through an algorithm to realize precise temperature control.

[0089] Example 3:

[0090] The embodiment introduces a control method of a temperature sensing and control system for TEM or SEM, and the specific steps include:

[0091] (1) The sample is irradiated by an electron beam, and the external driving module provides an electrical signal to the sample 6 through the electrical biasing unit 3 to form an electrical loop. In the process of electrification, the electrical loop generates Joule heat, and the Joule heat and the heat generated by irradiation together form the temperature of the sample 6.

[0092] (2) The temperature sensing unit 1 detects the temperature signal of the sample 6 in real time, and transmits the temperature signal to the external acquisition module.

[0093] (3) The external acquisition module receives and processes the temperature signal, and outputs the real-time temperature. The controller compares the real-time temperature with the target temperature.

[0094] (4) The external driving module adjusts the input electric signal of the temperature control unit 2 according to the temperature comparison result, so as to realize closed-loop accurate regulation of the temperature of the sample 6.

[0095] Example 4

[0096] In this embodiment, the performance of the temperature sensing and control chip is verified by using a finite element analysis software to perform multi-physical field coupling simulation on the chip.

[0097] In the heat conduction physical field, all solid structures are considered, and the initial temperature is set to room temperature (20℃). Except for the bottom surface of the substrate, the surface boundary conditions of the rest are set to be adiabatic to simulate the ideal heat insulation state. The bottom surface of the substrate is set to a constant temperature boundary, and the temperature is fixed at 20℃.

[0098] In the temperature sensing unit simulation process, the thermoelectric effect and electromagnetic heat effect are set to perform multi-physical field coupling simulation. Among them, the first thermocouple considers the thermoelectric coupling effect; the first thermocouple, the temperature sensing area, and the first heat dissipation area consider the Joule heat effect. The multi-physical fields are coupled and solved through the current physical field and the solid heat transfer physical field.

[0099] In the temperature control unit simulation process, the thermoelectric effect and electromagnetic heat effect are set to perform multi-physical field coupling simulation. Among them, the second thermocouple considers the thermoelectric coupling effect; the second thermocouple, the temperature control area, and the second heat dissipation area consider the Joule heat effect. The multi-physical fields are coupled and solved through the current physical field and the solid heat transfer physical field.

[0100] In order to optimize the performance of the device and take into account the feasibility of the MEMS micro-nano processing technology, the length, width, height of the thermocouple structure and the size of the applied current are parameterized and scanned. By comparing the temperature of the cold end of the device under different parameter combinations, the influence of different structure sizes and driving conditions on the refrigeration capacity of the device is analyzed, and the key geometric parameters and working current range of the semiconductor refrigerator device are determined accordingly, so as to realize the optimization balance between structure performance and preparation process.

[0101] The simulation results show that the output electric signal of the temperature sensing unit has a linear relationship with the temperature change, as shown in Figure 8 The external acquisition module can judge and output the real-time temperature according to the output electric signal. The electric signal received by the temperature control unit can adjust the temperature of the temperature control area, as shown in Figure 9 The external driving module can apply different currents to the temperature control unit to regulate the temperature of the temperature control area of the temperature control unit.

[0102] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A temperature sensing and control system for TEM or SEM, characterized in that: Specifically, it includes: A temperature sensing and control chip, which is electrically connected to an external acquisition and drive module; The temperature sensing and control chip includes: a substrate, a back cavity formed on the substrate, a support layer disposed on the back cavity, and a slope structure disposed around the periphery of the support layer; Temperature sensing units and temperature control units are disposed on the substrate and support layer; The support layer is provided with several observation windows; An electrical bias unit is provided around the observation window; The temperature sensing unit and the electrical bias unit are respectively disposed on both sides of the temperature control unit; the free ends of the temperature sensing unit, the electrical bias unit and the temperature control unit are all provided with electrode bonding blocks.

2. A temperature sensing and control system for TEM or SEM according to claim 1, characterized in that: An isolation cavity is provided on the support layer between the temperature sensing unit, the temperature control unit, and the electrical bias unit.

3. A temperature sensing and control system for TEM or SEM according to claim 1, characterized in that: The temperature sensing unit includes: a first thermocouple, a temperature sensing area, and a first heat dissipation area; the first thermocouple includes: a first N-type thermocouple arm and a first P-type thermocouple arm; the temperature sensing area is disposed on the support layer, and the first heat dissipation area opposite to the temperature sensing area is disposed on the support layer, the ramp structure, and the substrate; the first N-type thermocouple arm and the first P-type thermocouple arm are connected in series with one end of the first heat dissipation area through the temperature sensing area, and the other end of the first heat dissipation area is connected to the electrode bonding block.

4. A temperature sensing and control system for TEM or SEM according to claim 3, characterized in that: The temperature control unit includes: a second thermocouple, a temperature control area, and a second heat dissipation area; the second thermocouple includes: a second N-type thermocouple arm and a second P-type thermocouple arm; the temperature control area is provided on the support layer, and the second heat dissipation area opposite to the temperature control area is provided on the support layer, the slope structure, and the substrate; the second N-type thermocouple arm and the second P-type thermocouple arm are connected in series with one end of the second heat dissipation area through the temperature control area, and the other end of the second heat dissipation area is connected to the electrode bonding block.

5. A temperature sensing and control system for TEM or SEM according to claim 1, characterized in that: The temperature control zone is positioned between the temperature sensing zone and the electrical bias unit.

6. A temperature sensing and control system for TEM or SEM according to claim 4, characterized in that: The first thermocouple and temperature sensing area, the second thermocouple and temperature control area, the electrical bias unit, and the observation window are all located above the back cavity.

7. A temperature sensing and control system for TEM or SEM according to claim 1, characterized in that: The support layer is made of polyimide.

8. A temperature sensing and control system for TEM or SEM according to claim 1, characterized in that: The first thermocouple and the second thermocouple are made of bismuth telluride-based low-temperature thermoelectric materials.

9. A temperature sensing and control system for TEM or SEM according to any one of claims 1 to 8, characterized in that: The external acquisition and drive module includes: an external drive module, a controller, and an external acquisition module. The external drive module is electrically connected to the electrical bias unit and the temperature control unit, respectively. The external acquisition module is electrically connected to the temperature sensing unit, and the external drive module and the external acquisition module are electrically connected to the controller. The external acquisition module is used to receive the electrical signals acquired by the temperature sensing unit, convert them into temperature data, and transmit the temperature data to the controller. The external drive module is used to provide electrical signals to the temperature control unit and the electrical bias unit to adjust the sample temperature; The controller is used to compare the collected real-time temperature with the preset target temperature and generate a drive signal for the temperature control unit.

10. A control method for a temperature sensing and control system for TEM or SEM according to any one of claims 1 to 9, characterized in that: The specific steps include: Step 1: The sample is irradiated with an electron beam. The external drive module provides an electrical signal to the sample through the electrical bias unit to form an electrical circuit. Step 2: The temperature sensing unit detects the sample temperature signal in real time and transmits the temperature signal to the external acquisition module; Step 3: The external acquisition module receives and processes the temperature signal, and outputs the real-time temperature; the controller compares the real-time temperature with the target temperature. Step 4: The external drive module adjusts the input electrical signal of the temperature control unit according to the temperature comparison results to achieve closed-loop control of the sample temperature.

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