Hook-type probe and preparation method and application thereof

Abstract

The invention belongs to the technical field of precision machining, and particularly relates to a hook type probe and a preparation method and application thereof. Comprising the following steps: stretching a tungsten filament with the diameter of 60-100m into a cone shape by adopting a hot wire drawing method to obtain a conical probe rod; the small end of the conical probe rod is fused into a sphere through arc discharge, an external magnetic field in the horizontal direction is applied in the arc discharge process, the eccentricity of the sphere is controlled through Ampere force generated by the magnetic field, and the spoon-shaped probe is obtained. And immersing the spherical tail end of the spoon-shaped probe into an etching solution under the direct current voltage of 10V, and periodically extracting and immersing into alkali liquor at the time interval of 0.1-0.5 s and the constant speed of 1-10mu m / s to obtain a tip part with the curvature radius of 30-50nm. According to the method, the time for preparing one probe does not exceed 8 min, the TSV hole detection rate is larger than 99%, and the aperture deviation is larger than or equal to 5%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of precision machining, and particularly relates to a hook-shaped probe and a preparation method and application thereof. BACKGROUND

[0002] The manufacturing of through-silicon via (TSV) is a core process of advanced packaging, which is located in the back-end of chip manufacturing, and defects of which may cause the whole wafer to be defective, thus determining the packaging quality and performance stability of 3D chips. At present, atomic force microscopy is usually used to detect TSV slices, and a probe is used to scan the surface of a sample, and a three-dimensional topographic image of the sample surface is obtained by detecting the weak interaction force between the probe and the sample surface. It can be seen that the probe is extremely important in the detection process. Due to the surge in demand for TSV detection, the aspect ratio of 3D packaging TSV has increased from 3-4:1 to 10:1. Therefore, a probe with a hook structure and stronger wear resistance is needed due to the increase in the aspect ratio of the probe.

[0003] At present, a hook structure probe is usually prepared by focused ion beam carving, but it takes a long time to process one probe, usually more than 2 hours, and the heat damage in the preparation process will cause the needle tip to be brittle, which will seriously affect the detection accuracy of the through-silicon via. In addition, when a probe with an aspect ratio of 10:1 is prepared by this method, the rigidity and structural strength are insufficient during the detection process, which causes the problems of shaking and deviation during the detection process. At present, there is also an electrochemical etching method for preparing a probe, but this method cannot accurately control the eccentricity of the hook structure and the radius of curvature of the needle tip, so that the hook structure prepared by this method cannot accurately measure the internal structure of the through-silicon via during the detection process. SUMMARY

[0004] In order to solve the above problems, the present application provides a hook-shaped probe and a preparation method and application thereof.

[0005] The first aspect of the present application provides a preparation method of a hook-shaped probe for through-silicon via detection, comprising the following steps: The tungsten wire with a diameter of 60-100 µm is stretched into a conical shape by hot wire drawing to obtain a conical probe rod; since the diameter of the through-silicon via is 50-100 µm, the tungsten wire with a diameter of 60-100 µm is selected for stretching; specifically, since the prepared probe needs to meet the detection of a through-silicon via with an aspect ratio of 20:1, the diameter of the tungsten wire should be less than 60 µm, otherwise the probe rigidity will not be enough during the hot wire drawing process, which will affect the detection stability and accuracy; and the detection object is the inner wall of the through-silicon via with a diameter of 50-100 µm, so the probe with a diameter of less than 100 µm is needed, therefore the diameter of the selected tungsten wire should not be greater than 100 µm; The smaller end of the conical probe rod is melted into a spherical shape by arc discharge, and an external magnetic field in the horizontal direction is applied during the arc discharge process, and the Ampere force generated by the magnetic field is used to control the eccentricity of the spherical shape, so as to obtain a spoon-shaped probe; wherein the Ampere force calculation formula is as follows: F=I×∫dl×B; Wherein, I is the current, unit is A, dl is the effective length of the molten tungsten wire in the magnetic field, unit is m, B is the magnetic field strength, unit is T; wherein the current is 5A~20A, the effective length of the molten tungsten wire in the magnetic field is 10µm~100µm, and the magnetic field strength is 10mT~100mT; by controlling the current and the magnetic field strength, the accuracy of controlling the eccentricity of the spherical shape is controlled, so as to ensure that the curvature radius of the needle tip obtained after subsequent etching is 30nm~50nm; Under the action of direct current, the spherical end of the spoon-shaped probe is periodically extracted- immersed in the alkali solution at a uniform speed of 1µm / s~10µm / s with a time interval of 0.1s~0.5s, so as to etch the spherical end, obtain a needle tip part with a curvature radius of 30nm~50nm, and obtain a hook-shaped probe; specifically, 1 / 2 of the spherical part is immersed in the alkali solution for etching.

[0006] The present application first obtains a conical probe rod by hot wire drawing method, and then melts the smaller end of the conical probe rod into a spherical shape by arc discharge, and applies an external magnetic field in the horizontal direction during the arc discharge process, that is, the Ampere force generated by the interaction of 5A~20A current and 10mT~100mT magnetic field, to accurately control the spatial position of the molten tungsten ball, so that the molten ball is eccentric to form a hook blank; wherein the size of the Ampere force is used to accurately control the eccentricity, realize the directional control of the hook structure, so as to improve the detection accuracy of the through silicon via. Then, through electrochemical corrosion, the curvature radius of the needle tip is further controlled, and by using 10V direct current voltage, the probe is periodically extracted- immersed in the alkali solution at a uniform speed of 1µm / s~10µm / s with a time interval of 0.1s~0.5s, so as to finely control the final taper angle of the needle tip, that is, the sharpness, so as to obtain a needle tip part with a curvature radius of 30nm~50nm, and obtain a hook-shaped probe.

[0007] In another preferred embodiment, the specific process of hot wire drawing is as follows: The tungsten wire is heated to a molten state under a protective atmosphere, and is stretched at a stretching speed of 0.1 m / s to 1 m / s; preferably, the stretching is performed at a stretching speed of 0.5 m / s. Specifically, the molten state refers to heating the tungsten wire to a temperature close to the melting point of tungsten, which is about 3422 ℃. In actual operation, the part of the tungsten wire that needs to be stretched is locally heated to above 3400 ℃ by arc discharge or a high-temperature furnace, so that the front end is rapidly melted. The stretching rate is rapidly stretched at the moment when the tungsten wire is melted to form an elongated cone. The stretching speed is in the order of 0.1 m / s to 1 m / s, and the high-speed stretching ensures that the molten tungsten is thinned and lengthened before it solidifies. In order to improve the consistency of hot wire drawing, it is carried out in a sealed cavity of protective gas argon to prevent the tungsten from being oxidized at high temperature.

[0008] In another preferred embodiment, the aspect ratio of the conical probe rod is 10:1 to 20:1.

[0009] In another preferred embodiment, the parameters of the arc discharge are as follows: The pulse current density is 100 A / cm 2 ~ 200 A / cm 2 , the temperature is 8000 K to 10000 K, and the current is 5 A to 20 A.

[0010] In another preferred embodiment, the alkali solution is a NaOH solution with a concentration of 1 mol / L to 3 mol / L.

[0011] In another preferred embodiment, the direct current voltage refers to a 10 V direct current voltage.

[0012] In another preferred embodiment, an Al2O3 protective layer is further deposited on the surface of the needle tip of the hook-shaped probe.

[0013] In another preferred embodiment, the thickness of the Al2O3 protective layer is 5 nm to 50 nm.

[0014] The second aspect of the present application provides the hook-shaped probe prepared by the preparation method.

[0015] The third aspect of the present application provides the application of the hook-shaped probe in detecting through silicon vias.

[0016] Compared with the prior art, the present application has the following beneficial effects: The tungsten wire with a diameter of 60-100 mu m is selected to perform hot wire drawing, the tungsten wire with the diameter can ensure good rigidity and structural strength when the length-diameter ratio is 10:1, and bending during contact measurement in the detection process is avoided; in addition, the tungsten wire material itself has high rigidity and hardness, so that the rigidity and structural stability of the probe can be further ensured. After hot wire drawing, the external magnetic field in the horizontal direction is applied to assist the hook forming in the arc discharge process, under the conditions that the current is 5-20 A and the magnetic field strength is 10-100 mT, the ampere force generated by the magnetic field can accurately control the eccentricity of the spherical shape, realize the bending angle accuracy ± 5°, so as to obtain the probe with the hook structure, and through the electrochemical etching, the spoon-shaped probe is periodically extracted- immersed into the alkali solution under the conditions that the direct current voltage is 10 V, the time interval is 0.1-0.5 s, and the speed is 1-10 mu m / s, so as to accurately control the curvature radius of the needle tip, improve the sharpness of the needle tip, and then accurately measure the structure inside the through silicon via. The hook type probe prepared by the method of the present application not only can meet the length-diameter ratio of 10:1, but also has high rigidity and structural strength, can ensure the stability in the detection process, and can also ensure the detection accuracy of the through silicon via.

[0017] The hook type probe prepared by the method of the present application is of an integrated structure, which can effectively improve the overall structural strength and rigidity of the probe, and ensure that no deformation and wear occur when measuring the TSV inner size with a depth-width ratio greater than 10:1. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a process schematic diagram of the preparation method of the hook type probe of the present application.

[0019] Figure 2 It is a schematic diagram of the arc discharge process of the present application.

[0020] Figure 3 It is a schematic diagram of the magnetic field control of the spherical eccentricity of the present application; wherein, (a) is a schematic diagram of a magnetic field generating device, and (b) is a schematic diagram of the ampere force.

[0021] Figure 4 It is a schematic diagram of the electrochemical etching into a needle tip.

[0022] Figure 5 It is a schematic diagram of the TSV hole measurement point distribution and visual guidance system; wherein, (a) is a schematic diagram of the hook type probe in the detection of the workbench, and (b) is a schematic diagram of the machine vision guidance.

[0023] Figure 6This is a schematic diagram of the various parameters to be measured inside the TSV hole; where d represents the hole depth, R represents the top hole diameter, α represents the sidewall angle, R represents the roughness, and r represents the bottom hole diameter.

[0024] Figure 7 This is a photograph of the hook-shaped probe used in this invention. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following embodiments are commercially available unless otherwise specified.

[0026] The tungsten wires used in the following examples were purchased from Guangming Science and Technology Research Materials Co., Ltd., with a purity of 99.99% and a Mohs hardness of 7.5.

[0027] A method for preparing a hook-shaped probe, such as Figure 1 As shown, it includes the following steps: S1. A 60µm diameter tungsten wire rod is drawn into a conical shape with a taper of 85°~89° using an electric arc molten state. The tip of the tungsten wire rod is melted into a sphere by an electric arc discharge, and then the molten tungsten wire is drawn into a slender conical probe rod by rapidly moving the tungsten wire end along the axial direction. The parameters of the electric arc discharge are 5A~20A and the pulse current density is 100A / cm. 2 ~200A / cm 2 Temperature 8000K~10000K.

[0028] S2. An electric arc discharge is used to melt the tip of a conical probe rod into a spherical shape, and a spoon-shaped probe is obtained by controlling the eccentricity of the tungsten sphere. For example... Figure 2 As shown, a conical tungsten probe rod is used as the material, a platinum spark plug as the positive electrode, and a tungsten wire as the negative electrode. Both ends are connected in series to a high-voltage pulse power supply. The electrode material can be horizontally moved by a feeding mechanism to control the distance between the electrodes. When the smaller end of the tungsten wire approaches the spark plug, the high-voltage pulse breaks down the gas between the electrodes, generating an electric arc. The high temperature generated by the arc melts the smaller end of the tungsten wire, and the liquid tungsten condenses into a spherical shape under the action of surface tension. During the discharge process, in order to obtain a spoon-shaped probe, the center of the sphere needs to be offset from the probe rod's sub-axis by a certain distance. Figure 3 As shown, this is achieved by applying a horizontal external magnetic field. A Helmholtz coil generates a magnetic field B with variable magnetic induction intensity. After the electrodes are energized, free electrons inside the tungsten filament form a current I. Under the influence of the magnetic field, the moving charges inside are subjected to a vertical Lorentz force. This force is macroscopically manifested as an Ampere force on the tungsten sphere in the magnetic field. The formula for calculating the Ampere force is as follows: F=I x ∫dl x B; Wherein, I is the current unit A, l is the effective length of the molten tungsten wire in the magnetic field, unit m, B is the magnetic field strength, unit T; wherein, the current is 5A~20A, the effective length of the molten tungsten wire is 10µm~100µm, the magnetic field strength is 10mT~100mT.

[0029] In this process, the tungsten ball is subjected to the Ampere force and its own gravity; under the action of gravity, the molten spherical has a downward tendency and generates eccentricity, if the direction of Ampere force is the same as that of gravity, the eccentricity will increase, otherwise the eccentricity will decrease due to the Ampere force offsetting part of the gravity. Based on this principle, by controlling the direction and strength of the magnetic field, the eccentricity of the spherical can be adjusted, so that the solidified spherical produces a certain offset relative to the probe shaft, forming a spoon-shaped hook probe structure, that is, the probe tip is offset and hooked relative to the probe handle.

[0030] S3, using electrochemical corrosion method to fine etch the spoon-shaped blank probe into a needle tip. The electrochemical corrosion method is the fastest method for preparing a reliable needle tip, and the present application adopts the electrochemical method to etch the spoon-shaped probe. A NaOH solution with a concentration of 1~3mol / L is used as an electrolyte, the spoon-shaped probe to be etched is used as an anode, and a platinum wire is used as a cathode to form an electrolytic cell. A direct current voltage is applied to both ends of the electrode, and the etching rate of the needle tip can be controlled by adjusting the size of the direct current voltage; as shown in the figure, the spherical end of the spoon-shaped probe on the anode is periodically lifted and immersed in the alkali solution at a speed of 1µm / s~10µm / s by using a piezoelectric ceramic motor with high displacement resolution, so as to control the taper of the probe needle tip. The fine adjustment interval of 0.1s~0.5s and the lifting speed of 1µm / s~10µm / s are used to control the longitudinal size and aspect ratio of the probe needle tip. The appearance and size of the needle tip are observed at any time by an optical microscope, and when the etching reaches the designed taper and needle tip diameter, the power supply is cut off to stop the reaction, and the tungsten probe is taken out for cleaning and drying. By using the electrochemical etching method, a probe with a needle tip curvature radius of 30nm~50nm can be prepared. This preparation method takes into account the rigidity and spatial accessibility of the probe in high aspect ratio measurement, and lays a solid foundation for subsequent implementation of ultra-high resolution sidewall scanning measurement in a nano three-coordinate measurement system. Figure 4

[0031] The following will specifically describe a hook type probe and a preparation method and application thereof.

[0032] Embodiment 1: A preparation method of a hook type probe, comprising the following steps.

[0033] ​S1, a tungsten wire with a diameter of 60 pm is locally heated at the part to be stretched, and in this embodiment, the end of the tungsten wire is selected to be heated to above 3400 DEG C, so that the front end is rapidly melted, and stretched at a stretching speed of the order of 0.5 m / s, to obtain a conical probe rod with an aspect ratio of 20:1, and a taper of 85 DEG.

[0034] S2, as shown in Figure 2 , under the conditions of a pulse current density of 100 A / cm 2 , a temperature of 8000 K, and a current of 5 A, the smaller end of the conical probe rod is melted into a spherical shape by arc discharge, and during the arc discharge process, an external magnetic field in the horizontal direction is applied, and the Ampere force generated by the magnetic field is used to control the eccentricity of the spherical shape to 60 pm, and the bending angle is 90 DEG + 3 DEG, and after 8 min of processing, a spoon-shaped probe is obtained; wherein the Ampere force calculation formula is as follows: F = I x I dl x B.

[0035] Wherein, I is the current unit A, I is the effective length of the molten tungsten wire in the magnetic field, unit m, B is the magnetic field strength, unit T; wherein the current is 100 A / cm², the effective length of the tungsten wire is 60 pm, and the magnetic field strength is 10 mT.

[0036] S3, in a 3 mol / L NaOH solution, the spoon-shaped probe is periodically extracted- immersed into the NaOH solution at a time interval of 0.5 s and a speed of 10 pm / s under a direct current voltage of 10 V, to etch the spherical part, to obtain a needle tip part with a radius of curvature of 42 nm, and obtain a hook-shaped probe.

[0037] S4, an atomic layer deposition method is used to deposit Al2O3 on the needle tip part, to obtain an Al2O3 protective layer with a thickness of 30 nm; the atomic layer deposition parameters are: using trimethylaluminum and O3 precursors at a low temperature of 100 DEG C, 2 s of trimethylaluminum pulse, 30 s of nitrogen gas purging, and then 3 s of O3 pulse, under the condition of 300 times of cycle pulse, to deposit an Al2O3 coating layer with a thickness of 30 nm, to obtain a hook-shaped probe, as shown in Figure 7 .

[0038] Embodiment 2: a preparation method of a hook-shaped probe, comprising the following steps.

[0039] S1, a tungsten wire with a diameter of 70 pm is locally heated at the part to be stretched, and in this embodiment, the end of the tungsten wire is selected to be heated to above 3400 DEG C, so that the front end is rapidly melted, and stretched at a stretching speed of the order of 0.6 m / s, to obtain a conical probe rod with an aspect ratio of 15:1, and a taper of 89 DEG.

[0040] S2, by arc discharge, under the condition of pulse current density of 200 A / cm2, temperature of 8000 K, and current of 20 A, the smaller end of the conical probe rod is melted into a spherical shape by arc discharge, and during the arc discharge process, an external magnetic field in the horizontal direction is applied, and the Ampere force generated by the magnetic field is used to control the eccentricity of the spherical shape to 70 pm, the bending angle is 90°±3°, and after 8 min of treatment, a spoon-shaped probe is obtained; wherein the Ampere force calculation formula is as follows: F=I×∫dl×B.

[0041] wherein I is the current unit A, l is the effective length of the molten tungsten wire in the magnetic field, unit m, B is the magnetic field strength, unit T; wherein the current is 200 A / cm 2 , the effective length of the tungsten wire melting is 100 pm, and the magnetic field strength is 100 mT.

[0042] S3, in a 3 mol / L NaOH solution, the spoon-shaped probe is periodically extracted- immersed into the NaOH solution at a time interval of 0.5 s and a speed of 8 pm / s under a direct current voltage of 10 V, the spherical part is etched, a needle tip part with a radius of curvature of 40 nm is obtained, and a hook-shaped probe is obtained.

[0043] S4, an atomic layer deposition method is used to deposit Al2O3 on the needle tip part, and an Al2O3 protective layer with a thickness of 40 nm is obtained; the atomic layer deposition parameters are as follows: trimethylaluminum and O3 precursors are used at a low temperature of 100°C, trimethylaluminum pulse is 2 s, 30 s nitrogen gas purging is matched, then O3 pulse is 3 s, and 300 times of cycle pulse is performed under the above conditions to deposit 30 nm of Al2O3 coating, and a hook-shaped probe is obtained.

[0044] Embodiment 3: A preparation method of a hook-shaped probe, comprising the following steps.

[0045] S1, a tungsten wire with a diameter of 70 pm is locally heated at the part that needs to be stretched, in this embodiment, one end of the tungsten wire is selected to be heated to above 3400°C, the front end is rapidly melted, and stretching is performed at a stretching speed of 0.7 m / s to obtain a conical probe rod with a length-diameter ratio of 20:1, and the taper is 87°.

[0046] S2, as Figure 2As shown, by arc discharge, under the conditions of a pulse current density of 180 A / cm2, a temperature of 9000 K, and a current of 10 A, the smaller end of the conical probe rod is melted into a spherical shape by arc discharge, and during the arc discharge process, an external magnetic field in the horizontal direction is applied, and the Ampere force generated by the magnetic field is used to control the eccentricity of the spherical shape to 70 μm, the bending angle is 90°±3°, and after 8 min of treatment, a spoon-shaped probe is obtained; wherein the Ampere force calculation formula is as follows: F=I×∫dl×B.

[0047] Wherein, I is the current unit A, l is the effective length of the molten tungsten wire in the magnetic field, unit m, B is the magnetic field strength, unit T; wherein the current is 180 A / cm 2 , the effective length of the tungsten wire melting is 90 µm, and the magnetic field strength is 80 mT.

[0048] S3, in a 3 mol / L NaOH solution, periodically extract-immerse 1 / 2 of the spherical part of the spoon-shaped probe into the NaOH solution at a time interval of 0.5 s and a speed of 10 µm / s under a direct current voltage of 10 V, etch the spherical part, obtain a needle tip part with a radius of curvature of 40 nm, and obtain a hook-shaped probe.

[0049] S4, using an atomic layer deposition method, deposit Al2O3 on the needle tip part to obtain an Al2O3 protective layer with a thickness of 40 nm; the atomic layer deposition parameters are: using trimethylaluminum and O3 precursors at a low temperature of 100°C, 2s of trimethylaluminum pulse, 30s of nitrogen gas blowing, and then 3s of O3 pulse, under the condition of 300 times of cycle pulse, 30nm of Al2O3 coating is deposited, and a hook-shaped probe is obtained.

[0050] The hook-shaped probe prepared in Example 1 is used for detecting a through silicon via, and the detection object is a TSV aperture of 100 microns and a depth-width ratio of about 10:1. The three-dimensional spatial position of the TSV aperture is obtained by using machine vision guidance technology, wherein the machine vision guidance technology detection process is shown in Figure 5 (b), and the specific process is as follows.

[0051] Step 1: adaptive positioning.

[0052] The hook-shaped probe of the nano three-coordinate measuring machine, referred to as CMM, is guided to the top of the TSV hole, and then the hook-shaped probe is allowed to continuously measure in the hole by controlling the motion platform of the nano CMM. A local coordinate system in the TSV hole is established based on the principle of CMM coordinate measurement, the probe is controlled to enter the bottom of the TSV hole first, and then scan from the bottom to the top of the TSV hole in a straight line scanning mode, and the different measurement regions in the radial direction of the TSV are covered by the ultra-precision rotary worktable. The optimization of the measurement path is dynamically adjusted according to the ups and downs of the measured sample morphology, so as to ensure that the force between the probe and the hole wall is minimized and the probe is not damaged due to collision.

[0053] Step 2: Based on the actual morphology of the TSV, the appropriate X / Y / Z displacement amount is determined by machine learning. During the scanning process, the position of the probe and its contact with the hole wall are monitored in real time to ensure accurate measurement of the critical dimensions and the sidewall roughness, as shown in (a) of Figure 5 .

[0054] Step 3: Based on the three-dimensional coordinate data obtained by scanning, the five physical quantities of the TSV hole, i.e. the top and bottom diameters of the hole, the hole depth, the sidewall angle and the sidewall roughness, are calculated, as shown in Figure 6 .

[0055] The measurement results obtained by using the above method are shown in Table 1.

[0056] Table 1 TSV measurement results

[0057] As can be seen from the results in Table 1, the hook-shaped probe prepared by using the method in the present application can accurately measure the top and bottom diameters of the hole, the hole depth, the sidewall angle and the sidewall roughness in the TSV hole; the size repeatability is high, the average values of the top diameter, the bottom diameter and the hole depth are 100.017 µm, 89.987 µm and 100.098 µm respectively, and the corresponding standard deviations are only 0.042 µm, 0.038 µm and 0.170 µm, which indicates that the mechanical error of the probe in the three-dimensional positioning and scanning process is extremely small, and the hole diameter and depth can be stably reproduced. The sidewall angle has no drift, and the sidewall angle measured 6 times is all 0.26°, with a standard deviation of 0, which indicates that the probe does not introduce additional inclination or jitter when traveling in the hole, and can maintain an ideal vertical trajectory in a hole with a depth-to-width ratio of 10:1. The roughness measurement is stable, the average roughness is 150.85 nm, the standard deviation is 1.89 nm, and the fluctuation range is less than ±2 nm, which is much smaller than the roughness window of tens of nanometers usually concerned in the process, indicating that the contact force between the probe tip and the hole wall is consistent, the signal noise is low, and the probe can distinguish the subtle differences in the morphology of the TSV sidewall.

[0058] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A method for manufacturing a hook-type probe for through-silicon via inspection, characterized by, The method comprises the following steps: The tungsten wire with a diameter of 60-100 microns is stretched into a conical shape by a hot wire drawing method to obtain a conical probe rod; The smaller end of the conical probe rod is melted into a spherical shape by arc discharge, and a horizontal external magnetic field is applied during the arc discharge process, and the eccentricity of the spherical shape is controlled by the Ampere force generated by the magnetic field to obtain a spoon-shaped probe; wherein the Ampere force calculation formula is as follows: F=I×∫dl×B; Wherein, I is the current unit A, dl is the effective length of the molten tungsten wire in the magnetic field, unit m, B is the magnetic field strength, unit T; wherein the current is 5-20 A, the effective length of the molten tungsten wire in the magnetic field is 10-100 microns, and the magnetic field strength is 10-100 mT; Under the action of a direct current, the spherical end of the spoon-shaped probe is periodically extracted and immersed in an alkali solution at a uniform speed of 1-10 microns per second with a time interval of 0.1-0.5 seconds to etch the spherical end, so as to obtain a needle tip part with a radius of curvature of 30-50 nm, and obtain a hook-shaped probe.

2. The method for preparing the hook-shaped probe according to claim 1, characterized in that, The specific process of the hot wire drawing is as follows: The tungsten wire is heated and melted under a protective atmosphere, and stretched at a stretching speed of 0.1-1 m / s.

3. The method for preparing the hook-shaped probe according to claim 1, characterized in that, The length-diameter ratio of the conical probe rod is 10-20:

1.

4. The method for preparing the hook-shaped probe according to claim 1, characterized in that, The parameters of the arc discharge are as follows: The pulse current density is 100 A / cm 2 ~200 A / cm 2 The temperature is 8000K~10000K, and the current is 5A~20A.

5. The method for preparing the hook-shaped probe according to claim 1, characterized in that, The alkali solution is a NaOH solution with a concentration of 1-3 mol / L.

6. The method for preparing the hook-shaped probe according to claim 1, characterized in that, The direct current refers to a 10 V direct current.

7. The method for preparing the hook-shaped probe according to claim 1, characterized in that, Further comprising depositing an Al2O3 protective layer on the surface of the needle tip of the hook-shaped probe.

8. The method of claim 7, wherein the hook-shaped probe is prepared by the steps of: The thickness of the Al2O3 protective layer is 5-50 nm. ​ 9. A hook-shaped probe prepared by the preparation method of any one of claims 1-8.

10. The hook-shaped probe of claim 9 is used for detecting through silicon vias.

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