A method and system for removing surface oxide layers from superconducting devices

Abstract

The application relates to the technical field of superconducting devices, and discloses a superconducting device surface oxide layer removing method and system. A scanning device determines an abnormal oxidation area, a voltage is applied to the area until the oxide layer is broken down, the voltage is adjusted to detect the first resistance of the area after the area is broken down, the thickness of residual oxide layer in the area is collected when the first resistance meets a condition, the area is cleaned again by using a laser until the thickness is not greater than a first thickness threshold value, the voltage is increased to return to the execution of applying the voltage to the area until the residual thickness is less than a second thickness threshold value, the second resistance of the area after the area is broken down is detected, and the oxide layer removing judgment is completed according to the first resistance and the second resistance. Through the two oxide layer removing modes of the voltage and the laser, in combination with the detection of the resistance, the thickness and the like, the cyclic switching of the two modes is realized, so that the removing completeness of the superconducting device surface oxide layer removing is improved.

Description

Technical Field

[0001] This invention relates to the field of superconducting device technology, and in particular to a method and system for removing oxide layers from the surface of superconducting devices. Background Technology

[0002] Superconducting devices have enormous application potential in fields such as energy transmission, quantum computing, and medical imaging. However, when the surface of superconducting devices is exposed to air, undergoes specific processing procedures, or is in complex environments, an oxide layer easily forms. This oxide layer significantly affects the performance of superconducting devices, such as increasing resistance, reducing critical current density, and disrupting the stability of the superconducting state, thus limiting the practical application effectiveness and reliability of superconducting devices.

[0003] Currently, single oxide layer removal methods have certain limitations. For example, although laser oxide layer removal technology has advantages such as high precision, high energy density, and ease of control, it may not be able to completely remove oxide layers with special structures or distributions, and may cause certain thermal effects on the surface of superconducting devices during the process. On the other hand, the four-probe high-voltage oxide layer removal method can remove oxide layers by using the action of a high-voltage electric field, but the removal efficiency may be low for thicker or tightly bonded oxide layers.

[0004] In the actual oxide layer removal process, due to the lack of effective real-time monitoring methods, the use of the above methods to remove the oxide layer can easily cause device damage, and the oxide layer removal effect cannot be accurately evaluated, let alone the impact of oxide layer removal on the performance of superconducting devices.

[0005] Therefore, optimizing the removal process of oxide layers on device surfaces to improve the removal effect has become an urgent problem to be solved. Summary of the Invention

[0006] This invention provides a method and system for removing oxide layers from the surface of superconducting devices, in order to solve the problem of how to optimize the removal process of oxide layers on the device surface to improve the removal effect.

[0007] In a first aspect, the present invention provides a method for removing the oxide layer on the surface of a superconducting device, comprising: The surface of the superconducting device to be treated is scanned to identify abnormal oxidation regions. A first voltage value is applied to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down. The first voltage value is adjusted to the second voltage value to detect the abnormal oxidation region, and the first resistance state after the abnormal oxidation region breaks down is obtained. If the first resistance state does not meet the first preset condition, the residual thickness of the residual oxide layer in the abnormal oxidation region is collected in real time, and the second voltage value is less than the first voltage value. When the residual thickness is greater than the first thickness threshold, the abnormal oxidation area is cleaned with a laser until the residual thickness is no greater than the first thickness threshold. Then, the first voltage value is pressurized to obtain the first voltage value after pressurization. Using the first voltage value after pressurization as the first voltage value, return to the execution of applying the first voltage value at the abnormal oxidation region until the residual thickness is less than the second thickness threshold, and then detect the second resistance state after the abnormal oxidation region breaks down. Based on the first resistance state and the second resistance state, a pass / fail determination parameter is determined. When the pass / fail determination parameter meets the second preset condition, the oxide layer removal is determined to be complete.

[0008] Optionally, before the step of real-time acquisition of the residual thickness of the residual oxide layer in the abnormal oxidation region if the first resistance state does not meet the first preset condition, the method further includes: Detect whether the state of the first resistor meets the first preset condition; If the first resistance state meets the first preset condition, then the second resistance state after detecting the breakdown of the abnormal oxidation region is executed.

[0009] Optionally, if the first resistor state is a resistance value, then detecting whether the first resistor state satisfies the first preset condition includes: Detect whether the resistance value corresponding to the first resistance state is less than the resistance threshold. If the resistance value corresponding to the first resistance state is less than the resistance threshold, then determine that the first resistance state meets the first preset condition. If the resistance value corresponding to the first resistance state is not less than the resistance threshold, then it is determined that the first resistance state does not meet the first preset condition.

[0010] Optionally, it also includes: Obtain the overcurrent of the superconducting device to be processed; Applying a first voltage value at the abnormal oxidation region includes: A first voltage value is applied to the abnormal oxidation region, and the current applied is controlled to be less than the overcurrent.

[0011] Optionally, before detecting the second resistance state after the breakdown of the abnormal oxidation region, the method further includes: Detect the surface roughness at the abnormal oxidation region; If the surface roughness is less than the roughness threshold, then the second resistance state after the abnormal oxidation region is detected is performed. If the surface roughness is not less than the roughness threshold, then return to the step of applying the first voltage value at the abnormal oxidation region.

[0012] Optionally, the first resistance state is a first resistance value, and the second resistance state is a second resistance value. The step of determining the pass / fail judgment parameters based on the first resistance state and the second resistance state includes: Calculate the difference between the first resistance value and the second resistance value to obtain the resistance difference value, and compare the resistance difference value with the first resistance value to obtain the ratio value as a pass / fail judgment parameter; Detect whether the pass / fail judgment parameter is less than the ratio threshold. If the pass / fail judgment parameter is less than the ratio threshold, then determine that the pass / fail judgment parameter meets the second preset condition. If the pass / fail determination parameter is not less than the ratio threshold, then it is determined that the pass / fail determination parameter does not meet the second preset condition.

[0013] Optionally, after applying a first voltage value to the abnormal oxidation region until the oxide layer in the abnormal oxidation region is broken down, the method further includes: Record the breakdown voltage of the oxide layer in the abnormal oxidation region; After applying voltage to the first voltage value to obtain the applied first voltage value, the method further includes: Detect whether the first voltage value after pressurization exceeds the breakdown voltage; If the first voltage value after applying pressure exceeds the breakdown voltage, then the first voltage value after applying pressure is restored to the voltage value before applying pressure.

[0014] Optionally, before performing a surface scan on the superconducting device to be treated to determine the anomalous oxidation region, the method further includes: Obtain the device type of the superconducting device to be processed, and detect the initial thickness of the oxide layer on the surface of the superconducting device to be processed; Based on the device type and the initial thickness, determine whether to use voltage removal technology or laser removal technology to remove the oxide layer; If it is determined that the voltage removal technique will be used, then the surface of the superconducting device to be treated will be scanned to identify abnormal oxidation areas. If the laser removal technology is determined to be used, before performing a surface scan of the superconducting device to be treated to identify abnormal oxidation areas, the laser parameters are adjusted according to the initial thickness, and the oxidation layer of the superconducting device to be treated is removed using the laser parameters.

[0015] Optionally, after removing the oxide layer from the superconducting device to be treated using the laser parameters, the method further includes: Perform a surface scan on the superconducting device to be processed to identify abnormal oxidation regions.

[0016] In a second aspect, the present invention provides a superconducting device surface oxide layer removal system, the superconducting device surface oxide layer removal system comprising: a voltage probe device, a laser device, an ellipsometer monitoring device, and a control device, wherein the control device is connected to the voltage probe device, the laser device, and the ellipsometer monitoring device; The voltage probe device is used to scan the surface of the superconducting device to be treated, identify abnormal oxidation regions, and apply a first voltage value to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down. The voltage probe device is used to adjust the first voltage value to the second voltage value to detect the abnormal oxidation area, and the first resistance state after the abnormal oxidation area breaks down is obtained. If the first resistance state does not meet the first preset condition, the ellipsometry monitoring device is used to collect the residual thickness of the residual oxide layer in the abnormal oxidation area in real time. The second voltage value is less than the first voltage value. The laser device is used to clean the abnormal oxidation area with a laser when the residual thickness is greater than the first thickness threshold until the residual thickness is no greater than the first thickness threshold. Then, the first voltage value is applied in the voltage probe device to obtain the first voltage value after applying pressure. The voltage probe device is used to take the first voltage value after pressurization as the first voltage value, return to the execution of applying the first voltage value at the abnormal oxidation region until the residual thickness is less than the second thickness threshold, and then detect the second resistance state after the abnormal oxidation region breaks down. The control device is used to determine the qualification judgment parameters based on the first resistance state and the second resistance state, and to determine that the oxide layer removal is completed when the qualification judgment parameters meet the second preset condition.

[0017] The technical effects achieved by this invention compared to the prior art are as follows: This invention performs surface scanning on the superconducting device to be processed to identify abnormal oxidation regions. A first voltage value is applied to the abnormal oxidation region until the oxide layer in the abnormal oxidation region is broken down. The first voltage value is adjusted to a second voltage value to detect the abnormal oxidation region and obtain the first resistance state after the abnormal oxidation region is broken down. If the first resistance state does not meet a first preset condition, the residual thickness of the residual oxide layer in the abnormal oxidation region is collected in real time. If the second voltage value is less than the first voltage value, when the residual thickness is greater than a first thickness threshold, the abnormal oxidation region is cleaned with a laser until the residual thickness is not greater than the first thickness threshold. Then, the first voltage value is increased to obtain a first voltage value after the increase. The first voltage value after the increase is used as the first voltage value, and the process of applying the first voltage value to the abnormal oxidation region until the residual thickness is less than a second thickness threshold and then detecting the second resistance state after the abnormal oxidation region is broken down is repeated. Based on the first resistance state and the second resistance state, a pass / fail judgment parameter is determined. When the pass / fail judgment parameter meets a second preset condition, the oxide layer removal is determined to be complete. By combining voltage and laser methods to remove the oxide layer with the detection of resistance, thickness, and other parameters, the two methods can be switched cyclically. This improves the completeness of oxide layer removal on the surface of superconducting devices and effectively avoids damage to the superconducting devices during the removal process. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a superconducting device surface oxide layer removal system provided in Embodiment 1 of the present invention; Figure 2 This is a schematic flowchart of a method for removing the oxide layer on the surface of a superconducting device according to Embodiment 2 of the present invention; Among them, 1 is the processing platform; 2 is the superconducting device; 3 is the ellipsometer monitoring equipment; 4 is the voltage probe equipment; 5 is the semiconductor parameter analyzer; 6 is the laser equipment; 7 is the display screen; and 8 is the control equipment. Detailed Implementation

[0020] To make the technical problems solved, the technical solutions, and the beneficial effects 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 of the invention and are not intended to limit the invention.

[0021] like Figure 1 The diagram shown is a structural schematic of a superconducting device surface oxide layer removal system according to Embodiment 1 of the present invention. The system includes an ellipsometer monitoring device 3, a voltage probe device 4, a laser device 6, and a control device 8. The control device 8 is connected to the voltage probe device 4, the laser device 6, and the ellipsometer monitoring device 3. Of course, in... Figure 1 The diagram also shows a sample handling platform 1, a superconducting device 2, a semiconductor parameter analyzer 5, and a computer display screen 7. The sample handling platform 1 supports the superconducting device 2, ensuring its stability during processing and supporting strategies for devices on wafers of various sizes. The semiconductor parameter analyzer 5 is essentially part of a voltage probe device 4, connected to a control device 8. It precisely controls the high-voltage excitation and duration, and acquires voltage-current-resistance data in real time to accurately realize the output and input of the voltage probe device 4. The computer display screen is connected to the control device 8 to display data, images, and perform parameter input and debugging between various devices.

[0022] The ellipsometer monitoring device 3 is an optical measurement instrument used to detect thin film thickness, optical constants, and material microstructure. By measuring the change in polarization state of light before and after reflection from the device surface, it obtains the material's optical constants and structural information. During oxide layer removal, the ellipsometer monitoring device 3 emits polarized light and measures the change in polarization state of the reflected light, acquiring real-time information such as the thickness, optical constants, and microstructure of the film layer on the device surface. It can monitor changes in oxide layer thickness and optical properties in real time, providing a basis for optimizing the oxide layer removal process. Therefore, in... Figure 2 The diagram shows the transmitter and receiver of the ellipsometer monitoring device 3. The two ends correspond to each other, one transmitting optical signals and the other receiving optical signals. After signal analysis, the results are obtained.

[0023] The voltage probe device 4 of this invention can employ a four-probe high-voltage device. The four-probe method is a commonly used electrical testing technique for thin-film devices, often used to measure the resistivity, conductivity, and other electrical properties of materials. In this invention, it is used to remove the oxide layer. By applying a high voltage to the safe testing area of ​​the device under test, four probes accurately guide current through the safe area, causing the oxide layer to undergo physical or chemical changes under the influence of the high-voltage electric field, thereby achieving oxide layer removal. The high voltage may cause ions in the oxide layer to migrate or chemical bonds to break, prompting the oxide layer to peel off from the device surface.

[0024] Laser device 6 utilizes the principle of laser removal of oxide layers, specifically the thermal effect of laser-material interaction. When a high-energy laser beam irradiates the surface of a superconducting device, the laser energy is absorbed by the oxide layer and converted into heat energy, causing the oxide layer to rapidly heat up to its melting or boiling point, thereby removing the oxide layer. For superconducting devices, laser parameters need to be optimized to avoid adverse effects on superconducting performance. Laser device 6 may include a pulsed laser generator and a laser focusing and scanning device. The pulsed laser generator can generate a laser beam with a specific wavelength, pulse energy, pulse width, and repetition frequency. The laser focusing and scanning device is used to focus the laser beam onto the oxide layer on the device surface and scan it according to a preset path.

[0025] The control device 8 can essentially be a processor, specifically a computer device, etc. It can receive data from the voltage probe device 4, the laser device 6, and the ellipsometry monitoring device 3, perform comprehensive analysis and processing, and adjust voltage parameters, laser parameters, and scanning paths based on the analysis results to achieve automated control and real-time optimization of the oxide layer removal process.

[0026] Specifically, the control process is as follows: The voltage probe device is used to scan the surface of the superconducting device to be treated, identify abnormal oxidation regions, and apply a first voltage value to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down. The voltage probe device is used to adjust the first voltage value to the second voltage value to detect the abnormal oxidation area, and the first resistance state after the abnormal oxidation area breaks down is obtained. If the first resistance state does not meet the first preset condition, the ellipsometry monitoring device is used to collect the residual thickness of the residual oxide layer in the abnormal oxidation area in real time. The second voltage value is less than the first voltage value. The laser device is used to clean the abnormal oxidation area with a laser when the residual thickness is greater than the first thickness threshold until the residual thickness is no greater than the first thickness threshold. Then, the first voltage value is applied in the voltage probe device to obtain the first voltage value after applying pressure. The voltage probe device is used to take the first voltage value after pressurization as the first voltage value, return to the execution of applying the first voltage value at the abnormal oxidation region until the residual thickness is less than the second thickness threshold, and then detect the second resistance state after the abnormal oxidation region breaks down. The control device is used to determine the qualification judgment parameters based on the first resistance state and the second resistance state, and to determine that the oxide layer removal is completed when the qualification judgment parameters meet the second preset condition.

[0027] In this embodiment of the invention, the surface of the superconducting device to be processed is scanned to identify abnormal oxidation regions. A first voltage value is applied to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down. The first voltage value is adjusted to a second voltage value to detect the abnormal oxidation regions and obtain the first resistance state after the abnormal oxidation regions are broken down. If the first resistance state does not meet a first preset condition, the residual thickness of the residual oxide layer in the abnormal oxidation regions is collected in real time. If the second voltage value is less than the first voltage value, and the residual thickness is greater than a first thickness threshold, the abnormal oxidation regions are cleaned with a laser until the residual thickness is not greater than the first thickness threshold. Then, the first voltage value is increased to obtain a first voltage value after the increase. The first voltage value after the increase is used as the first voltage value, and the process returns to applying the first voltage value to the abnormal oxidation regions until the residual thickness is less than a second thickness threshold, and then detecting the second resistance state after the abnormal oxidation regions are broken down. Based on the first resistance state and the second resistance state, a pass / fail judgment parameter is determined. When the pass / fail judgment parameter meets a second preset condition, the oxide layer removal is determined to be complete. By combining voltage and laser methods to remove the oxide layer with the detection of resistance, thickness, and other parameters, the two methods can be switched cyclically. This improves the completeness of oxide layer removal on the surface of superconducting devices and effectively avoids damage to the superconducting devices during the removal process.

[0028] like Figure 2 The diagram shown is a flowchart illustrating a method for removing the oxide layer on the surface of a superconducting device according to Embodiment 2 of the present invention. This method may include the following steps: Step S201: Perform a surface scan on the superconducting device to be processed to identify abnormal oxidation regions, and apply a first voltage value to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down.

[0029] Among them, the surface scanning of superconducting devices can be performed using ellipsometer monitoring equipment, voltage probe equipment, etc., that is, the surface scanning of the device can be performed using any equipment capable of surface scanning, and the present invention does not limit it.

[0030] In step S201 of this invention, when the surface is scanned to determine the abnormal oxidation region, the detection is performed by a voltage probe device. The specific function of the voltage probe device is described later. This voltage probe device can be adjusted to use a low voltage (e.g., 0.1V) to scan and plot the initial resistance distribution of the superconducting device surface, thereby marking abnormally high resistance points (e.g., resistance values ​​greater than 1000Ω). Then, an abnormally high resistance point is selected as the abnormal oxidation region, and a high voltage (i.e., a first voltage value) is applied to the abnormal oxidation region. The duration of the applied voltage can be set as needed to break down the oxide layer at that location. The high voltage can be selected as any voltage value between 3V and 20V.

[0031] Since superconducting devices and the like can not withstand breakdown voltages of hundreds of volts or thousands of volts, the high voltage and low voltage defined in this invention are relative to both, rather than conventionally defined high and low voltage.

[0032] Optionally, the method for removing the oxide layer on the surface of the superconducting device further includes: Obtain the overcurrent of the superconducting device to be processed; Applying a first voltage value at the abnormal oxidation region includes: A first voltage value is applied to the abnormal oxidation region, and the current applied is controlled to be less than the overcurrent.

[0033] When applying voltage to the abnormal oxidation region, the current applied must be limited. The maximum limit of this current is the overcurrent of the superconducting device. That is, the current applied when the voltage is applied cannot exceed the overcurrent, for example, the current should not exceed 10mA, so as to avoid overcurrent damage to the superconducting device.

[0034] Optionally, before performing a surface scan on the superconducting device to be treated to determine the anomalous oxidation region, the method further includes: Obtain the device type of the superconducting device to be processed, and detect the initial thickness of the oxide layer on the surface of the superconducting device to be processed; Based on the device type and the initial thickness, determine whether to use voltage removal technology or laser removal technology to remove the oxide layer; If it is determined that the voltage removal technique will be used, then the surface of the superconducting device to be treated will be scanned to identify abnormal oxidation areas. If the laser removal technology is determined to be used, before performing a surface scan of the superconducting device to be treated to identify abnormal oxidation areas, the laser parameters are adjusted according to the initial thickness, and the oxidation layer of the superconducting device to be treated is removed using the laser parameters.

[0035] In this embodiment, the superconducting device can be identified first, and the oxide layer can be removed by voltage removal technology or laser removal technology based on the device type and the initial thickness of the surface oxide layer.

[0036] Voltage removal technology involves applying voltage to abnormal oxidation areas to cause ions in the oxide layer to migrate and chemical bonds to break down the oxide layer, thus causing the oxide layer to peel off from the device surface. Laser removal technology involves irradiating the oxide layer with a laser, causing the oxide layer to heat up rapidly to its melting or boiling point, thereby removing the oxide layer.

[0037] For superconducting devices with a relatively thick initial thickness that can be removed at high temperatures, laser removal technology can be used directly as the first step. For superconducting devices with a relatively thin initial thickness that cannot be removed at high temperatures, voltage removal technology can be used. Through the above judgment and selection, an effective removal method can be selected, thereby improving the removal efficiency.

[0038] For example, the removal method can be selected based on the device type (superconducting / ordinary electronic device) and the oxide layer condition (thickness, uniformity). The steps are as follows: 1. Preprocessing and Evaluation The initial thickness and optical constants of the oxide layer on the device surface were measured using an ellipsometer. The removal method should be selected based on the device type (superconducting / ordinary electronic device) and the oxide layer condition (thickness, uniformity): For ordinary electronic devices or devices with thin oxide films (<0.5 μm): a four-probe high-voltage system is preferred for removal; for superconducting devices and other devices with electrostatic ablation risk or severe local oxidation: a laser removal system is preferred.

[0039] 2. Four-probe high-voltage removal (applicable to general electronic devices or devices with thin oxide films (<0.5 μm)) Four probes are placed on the surface of the device, and an optimized high voltage signal (5~20V, the specific voltage and duration are adjusted according to the characteristics of the material and oxide layer) is applied. Current flows through the oxide film layer between the two probes, which creates a strong electric field inside and induces the defects in the oxide layer to produce an avalanche effect, destroying its structure and causing the resistance to drop sharply. During this process, the resistance change is monitored in real time, and the process stops when the resistance stabilizes to the expected value.

[0040] 3. Laser removal (applicable to superconducting devices or severe oxidation) The laser parameters (wavelength, energy, pulse width, and frequency) are adjusted based on the surface oxide film thickness data obtained from the ellipsometer. The energy is increased in areas with thick oxide layers and decreased in areas with thin oxide layers. The laser is focused and scanned to vaporize and remove the oxide layer. The ellipsometer film thickness parameters and effects are monitored in real time during the process.

[0041] 4. Ellipsometry-assisted testing and effect verification After removal, the surface thickness, optical constants, and microstructure are measured again using an ellipsometry; the performance is comprehensively evaluated by combining the resistance data from the four-probe low-voltage constant voltage test; if the standard is not met, the process is repeated.

[0042] Optionally, after removing the oxide layer from the superconducting device to be treated using the laser parameters, the method further includes: Perform a surface scan on the superconducting device to be processed to identify abnormal oxidation regions.

[0043] After using lasers to remove superconducting devices, voltage removal technology can be used to avoid burning the surface of the superconducting device at high temperatures and to improve the integrity of surface removal.

[0044] Step S202: Adjust the first voltage value to the second voltage value to detect the abnormal oxidation region and obtain the first resistance state after the abnormal oxidation region breaks down. If the first resistance state does not meet the first preset condition, the residual thickness of the residual oxide layer in the abnormal oxidation region is collected in real time.

[0045] The second voltage value is less than the first voltage value, meaning the first voltage value is high and the second voltage value is low. Here, the voltage of the device is lowered to detect the resistance after the abnormal oxidation region breaks down (i.e., the first resistance state). The second voltage value can be 0.1V, which means the voltage is lowered from the first voltage value to the second voltage value to perform resistance detection on the device and obtain the first resistance state.

[0046] If the resistance is less than a certain value, it indicates that the surface oxide layer has been removed. If the resistance is not less than the value, it indicates that the surface oxide layer has not been completely removed and the oxide layer needs to be removed again in the abnormally oxidized area.

[0047] The residual thickness can be detected by an ellipsometer monitoring device, which allows for subsequent selection of whether to switch removal methods based on the residual thickness. Throughout the entire oxide layer removal process, the ellipsometer monitoring device can detect the thickness of the surface oxide layer. Of course, it can also collect the thickness of the surface oxide layer when the detection is triggered.

[0048] Optionally, before the step of real-time acquisition of the residual thickness of the residual oxide layer in the abnormal oxidation region if the first resistance state does not meet the first preset condition, the method further includes: Detect whether the state of the first resistor meets the first preset condition; If the first resistance state meets the first preset condition, then the second resistance state after detecting the breakdown of the abnormal oxidation region is executed.

[0049] If the first resistance state is detected to meet the first preset condition, for example, the resistance value is less than a certain value, then the second resistance state after the abnormal oxidation region is broken down in the subsequent step S204 is executed, that is, the jump is realized, and the step S203 is not executed, thereby improving the determination efficiency.

[0050] Optionally, if the first resistor state is a resistance value, then detecting whether the first resistor state satisfies the first preset condition includes: Detect whether the resistance value corresponding to the first resistance state is less than the resistance threshold. If the resistance value corresponding to the first resistance state is less than the resistance threshold, then determine that the first resistance state meets the first preset condition. If the resistance value corresponding to the first resistance state is not less than the resistance threshold, then it is determined that the first resistance state does not meet the first preset condition.

[0051] In this method, a first resistance state is taken as a resistance value, and a first preset condition is set as the condition for determining the magnitude of the resistance value and the resistance threshold. If the resistance value is less than the resistance threshold, it is determined that the first preset condition is met; if the resistance is not less than the resistance threshold, it is determined that the first preset condition is not met. Using the resistance value to determine the state of oxide layer removal can be accurately achieved.

[0052] Step S203: When the residual thickness is greater than the first thickness threshold, the abnormal oxidation area is cleaned with a laser until the residual thickness is no greater than the first thickness threshold. Then, the first voltage value is pressurized to obtain the first voltage value after pressurization.

[0053] The residual thickness is compared with a first thickness threshold, for example, 20 nm. If the residual thickness is greater than the first thickness threshold, the effect of removing it by voltage is poor when the thickness is high. Therefore, laser can be used to clean the area to remove the oxide layer, which can improve efficiency.

[0054] The thickness of the oxide layer is monitored in real time, so that the oxide layer can be removed by voltage after the residual thickness is no greater than the first thickness threshold. Of course, since the voltage used before is not sufficient to remove the oxide layer, the voltage needs to be increased to increase the voltage value when removing the oxide layer.

[0055] The voltage applied to the first voltage value can be applied in a fixed step size, for example, a step size of 0.5V. When the current first voltage value is 3V, the applied first voltage value will be 3.5V when the voltage is removed in the next step. If the voltage cannot be completely removed in the next step, the process will repeat in step S203 to apply voltage to the first voltage value, resulting in an applied first voltage value of 4V.

[0056] Optionally, after applying a first voltage value to the abnormal oxidation region until the oxide layer in the abnormal oxidation region is broken down, the method further includes: Record the breakdown voltage of the oxide layer in the abnormal oxidation region; After applying voltage to the first voltage value to obtain the applied first voltage value, the method further includes: Detect whether the first voltage value after pressurization exceeds the breakdown voltage; If the first voltage value after applying pressure exceeds the breakdown voltage, then the first voltage value after applying pressure is restored to the voltage value before applying pressure.

[0057] In addition, after breaking down the oxide layer in the abnormal oxidation region, it is also necessary to record the breakdown voltage of the oxide layer in the abnormal oxidation region. During subsequent pressurization, this breakdown voltage should be avoided to prevent breakdown damage to the superconducting device.

[0058] Step S204: Using the first voltage value after pressurization as the first voltage value, return to the execution of applying the first voltage value at the abnormal oxidation region until the residual thickness is less than the second thickness threshold, and then detect the second resistance state after the abnormal oxidation region breaks down.

[0059] The first voltage value formed after pressurization is used as the first voltage value, and the process of removing the oxide layer by voltage is repeated until the residual thickness is detected to be less than a second thickness threshold. This second thickness threshold is less than the first thickness threshold; for example, the second thickness threshold is 0.5 nm. If the residual thickness is less than the second thickness threshold, the second resistance state of the abnormally oxidized area at this time needs to be detected and compared with the first resistance state to determine whether the removal effect is qualified.

[0060] The second resistance state after breakdown of the abnormal oxidation region is detected by performing resistance detection on the device by adjusting the voltage of the voltage probe device to a low voltage (e.g., 0.1V).

[0061] Optionally, before detecting the second resistance state after the breakdown of the abnormal oxidation region, the method further includes: Detect the surface roughness at the abnormal oxidation region; If the surface roughness is less than the roughness threshold, then the second resistance state after the abnormal oxidation region is detected is performed. If the surface roughness is not less than the roughness threshold, then return to the step of applying the first voltage value at the abnormal oxidation region.

[0062] In addition to detecting the thickness, it is also necessary to detect the surface roughness of the abnormal oxidation areas to improve the uniformity of oxide layer removal and enhance the removal effect. In one embodiment, the roughness threshold can be 2 nm.

[0063] Step S205: Determine the qualification criteria parameters based on the first resistance state and the second resistance state. When the qualification criteria parameters meet the second preset condition, determine that the oxide layer removal is complete.

[0064] The qualified judgment parameter can be calculated from the first resistance state and the second resistance state, and is used to express the change of resistance state between the first resistance state and the second resistance state. When the two resistance state changes meet the second preset condition, the oxide layer removal is determined to be complete.

[0065] Optionally, the first resistance state is a first resistance value, and the second resistance state is a second resistance value. The step of determining the pass / fail judgment parameters based on the first resistance state and the second resistance state includes: Calculate the difference between the first resistance value and the second resistance value to obtain the resistance difference value, and compare the resistance difference value with the first resistance value to obtain the ratio value as a pass / fail judgment parameter; Detect whether the pass / fail judgment parameter is less than the ratio threshold. If the pass / fail judgment parameter is less than the ratio threshold, then determine that the pass / fail judgment parameter meets the second preset condition. If the pass / fail determination parameter is not less than the ratio threshold, then it is determined that the pass / fail determination parameter does not meet the second preset condition.

[0066] In this embodiment, the second preset condition can be ΔR / R1<5%, which is considered qualified. Here, R1 is the first resistance value, ΔR=|R2-R1|, R2 is the second resistance value, and the ratio threshold is 5%.

[0067] For example, a voltage breakdown-laser cleaning synergistic mechanism can be used: low-voltage pre-detection → high-voltage breakdown positioning → precise laser cleaning steps. Step S1: Use a four-probe low-voltage scan (0.1V) to plot the initial resistance distribution and mark abnormally high resistance points (R>1000Ω). Step S2: Apply a high voltage to the abnormally high resistance area marked on the device surface using a stepped voltage boost method (5V→8V→12V→15V……20V or 3V→3.5V→4V→……20V, lasting 50ms) to break down the oxide layer at that location. Record the breakdown voltage Vbd. Then adjust the applied voltage to a constant voltage of 0.1V and test the resistance R1 after breakdown in situ. Note that in step S2, apply a current limit of ≤10 mA to the semiconductor parameter analyzer (to prevent overcurrent damage to the device). If R1 < 10Ω, it proves that the surface oxide film layer has been completely removed, and then proceed to step S5; If R1 > 10Ω, it proves that the surface oxide layer has not been completely removed, so proceed to step S3 and use an ellipsometry for further analysis; Step S3: The ellipsometer scans the breakdown area. If the residual oxide layer thickness is detected to be >20nm, laser cleaning is initiated (energy density 1.2J / cm²). If the residual oxide layer thickness is detected to be <20nm, return to step S2 and continue increasing the pressure. Step S4: The ellipsometry provides real-time feedback on the cleaning progress until the oxide layer thickness is <0.5nm and the surface roughness Ra is <2nm; Step S5: Apply a constant voltage of 0.1V to the four probes and retest resistor R2. If ΔR / R1 < 5%, it is considered qualified; otherwise, return to S3.

[0068] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for removing the oxide layer on the surface of a superconducting device, characterized in that, include: The surface of the superconducting device to be treated is scanned to identify abnormal oxidation regions. A first voltage value is applied to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down. The first voltage value is adjusted to the second voltage value to detect the abnormal oxidation region, and the first resistance state after the abnormal oxidation region breaks down is obtained. If the first resistance state does not meet the first preset condition, the residual thickness of the residual oxide layer in the abnormal oxidation region is collected in real time, and the second voltage value is less than the first voltage value. When the residual thickness is greater than the first thickness threshold, the abnormal oxidation area is cleaned with a laser until the residual thickness is no greater than the first thickness threshold. Then, the first voltage value is pressurized to obtain the first voltage value after pressurization. Using the first voltage value after pressurization as the first voltage value, return to the execution of applying the first voltage value at the abnormal oxidation region until the residual thickness is less than the second thickness threshold, and then detect the second resistance state after the abnormal oxidation region breaks down. Based on the first resistance state and the second resistance state, a pass / fail judgment parameter is determined. When the pass / fail judgment parameter meets the second preset condition, the oxide layer removal is determined to be complete. Before the step of real-time acquisition of the residual thickness of the residual oxide layer in the abnormal oxidation region if the first resistance state does not meet the first preset condition, the method further includes: Detect whether the state of the first resistor meets the first preset condition; If the first resistor state is a resistance value, then detecting whether the first resistor state satisfies the first preset condition includes: Detect whether the resistance value corresponding to the first resistance state is less than the resistance threshold. If the resistance value corresponding to the first resistance state is not less than the resistance threshold, then determine that the first resistance state does not meet the first preset condition. The first resistance state is a first resistance value, and the second resistance state is a second resistance value. The step of determining the pass / fail judgment parameters based on the first resistance state and the second resistance state includes: Calculate the difference between the first resistance value and the second resistance value to obtain the resistance difference value, and compare the resistance difference value with the first resistance value to obtain the ratio value as a pass / fail judgment parameter; Detect whether the pass / fail judgment parameter is less than the ratio threshold. If the pass / fail judgment parameter is less than the ratio threshold, then determine that the pass / fail judgment parameter meets the second preset condition. If the pass / fail determination parameter is not less than the ratio threshold, then it is determined that the pass / fail determination parameter does not meet the second preset condition.

2. The method for removing the oxide layer on the surface of a superconducting device according to claim 1, characterized in that, After detecting whether the state of the first resistor meets the first preset condition, the method further includes: If the first resistance state meets the first preset condition, then the second resistance state after detecting the breakdown of the abnormal oxidation region is executed.

3. The method for removing the oxide layer on the surface of a superconducting device according to claim 2, characterized in that, The step of detecting whether the state of the first resistor meets the first preset condition further includes: If the resistance value corresponding to the first resistance state is less than the resistance threshold, then the first resistance state is determined to satisfy the first preset condition.

4. The method for removing the oxide layer on the surface of a superconducting device according to claim 1, characterized in that, Also includes: Obtain the overcurrent of the superconducting device to be processed; Applying a first voltage value at the abnormal oxidation region includes: A first voltage value is applied to the abnormal oxidation region, and the current applied is controlled to be less than the overcurrent.

5. The method for removing the oxide layer on the surface of a superconducting device according to claim 1, characterized in that, Before detecting the second resistance state after the breakdown of the abnormal oxidation region, the method further includes: Detect the surface roughness at the abnormal oxidation region; If the surface roughness is less than the roughness threshold, then the second resistance state after the abnormal oxidation region is detected is performed. If the surface roughness is not less than the roughness threshold, then return to the step of applying the first voltage value at the abnormal oxidation region.

6. The method for removing the oxide layer on the surface of a superconducting device according to claim 1, characterized in that, After applying a first voltage value to the abnormal oxidation region until the oxide layer in the abnormal oxidation region is broken down, the method further includes: Record the breakdown voltage of the oxide layer in the abnormal oxidation region; After applying voltage to the first voltage value to obtain the applied first voltage value, the method further includes: Detect whether the first voltage value after pressurization exceeds the breakdown voltage; If the first voltage value after applying pressure exceeds the breakdown voltage, then the first voltage value after applying pressure is restored to the voltage value before applying pressure.

7. The method for removing the oxide layer on the surface of a superconducting device according to claim 1, characterized in that, Before performing a surface scan on the superconducting device to be treated to determine the abnormal oxidation region, the procedure also includes: Obtain the device type of the superconducting device to be processed, and detect the initial thickness of the oxide layer on the surface of the superconducting device to be processed; Based on the device type and the initial thickness, determine whether to use voltage removal technology or laser removal technology to remove the oxide layer; If it is determined that the voltage removal technique will be used, then the surface of the superconducting device to be treated will be scanned to identify abnormal oxidation areas. If the laser removal technology is determined to be used, before performing a surface scan of the superconducting device to be treated to identify abnormal oxidation areas, the laser parameters are adjusted according to the initial thickness, and the oxidation layer of the superconducting device to be treated is removed using the laser parameters.

8. The method for removing the oxide layer on the surface of a superconducting device according to claim 7, characterized in that, After removing the oxide layer from the superconducting device to be treated using the laser parameters, the process further includes: Perform a surface scan on the superconducting device to be processed to identify abnormal oxidation regions.

9. A system for removing oxide layers from the surface of superconducting devices, characterized in that, The superconducting device surface oxide layer removal system includes: a voltage probe device, a laser device, an ellipsometer monitoring device, and a control device, wherein the control device is connected to the voltage probe device, the laser device, and the ellipsometer monitoring device; The voltage probe device is used to scan the surface of the superconducting device to be treated, identify abnormal oxidation regions, and apply a first voltage value to the abnormal oxidation regions until the oxide layer in the abnormal oxidation regions is broken down. The voltage probe device is used to adjust the first voltage value to the second voltage value to detect the abnormal oxidation area, and the first resistance state after the abnormal oxidation area breaks down is obtained. If the first resistance state does not meet the first preset condition, the ellipsometry monitoring device is used to collect the residual thickness of the residual oxide layer in the abnormal oxidation area in real time. The second voltage value is less than the first voltage value. The laser device is used to clean the abnormal oxidation area with a laser when the residual thickness is greater than the first thickness threshold until the residual thickness is no greater than the first thickness threshold. Then, the first voltage value is applied in the voltage probe device to obtain the first voltage value after applying pressure. The voltage probe device is used to take the first voltage value after pressurization as the first voltage value, return to the execution of applying the first voltage value at the abnormal oxidation region until the residual thickness is less than the second thickness threshold, and then detect the second resistance state after the abnormal oxidation region breaks down. The control device is used to determine the qualification judgment parameters based on the first resistance state and the second resistance state, and to determine that the oxide layer removal is completed when the qualification judgment parameters meet the second preset condition; Before the step of real-time acquisition of the residual thickness of the residual oxide layer in the abnormal oxidation region if the first resistance state does not meet the first preset condition, the method further includes: Detect whether the state of the first resistor meets the first preset condition; If the first resistor state is a resistance value, then detecting whether the first resistor state satisfies the first preset condition includes: Detect whether the resistance value corresponding to the first resistance state is less than the resistance threshold. If the resistance value corresponding to the first resistance state is not less than the resistance threshold, then determine that the first resistance state does not meet the first preset condition. The first resistance state is a first resistance value, and the second resistance state is a second resistance value. The step of determining the pass / fail judgment parameters based on the first resistance state and the second resistance state includes: Calculate the difference between the first resistance value and the second resistance value to obtain the resistance difference value, and compare the resistance difference value with the first resistance value to obtain the ratio value as a pass / fail judgment parameter; Detect whether the pass / fail judgment parameter is less than the ratio threshold. If the pass / fail judgment parameter is less than the ratio threshold, then determine that the pass / fail judgment parameter meets the second preset condition. If the pass / fail determination parameter is not less than the ratio threshold, then it is determined that the pass / fail determination parameter does not meet the second preset condition.

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