Magnetic probe and SQUID combined module and application and method thereof

Abstract

The SQUID combined module for the scanning magnetic microscope is characterized in that a permalloy sheet is adhered to one surface, which does not contain a magnetic flux induction junction area, of an SQUID chip by adopting low-temperature glue; a magnetic probe is pasted on one side, containing a magnetic flux induction junction area, of an SQUID chip through low-temperature glue, the magnetic probe is located in the SQUID chip receiving coil, the physical center of the magnetic probe is far away from the SQUID magnetic flux induction junction area, an inner core of the magnetic probe is a conical solid quartz needle, permalloy films are deposited on the side surface and the bottom faces of the two ends of the solid quartz needle in a sputtering mode, and the magnetic flux induction junction area is formed. And after the sputtering deposition of the permalloy film is completed, the tip and the tail end of the magnetic probe are subjected to multiple times of high-precision cutting processing by adopting a laser cutting processing technology. The invention also provides a manufacturing method of the magnetic probe and a defect detection method for an integrated circuit chip. And the signal coupling rate during detection can be greatly increased while the sub-micron spatial resolution is ensured to be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic detection, and relates to a superconducting quantum interference device (Superconducting Quantum Interference Device, abbreviated as SQUID chip), which is a SQUID chip used as the core component of the probe of a scanning SQUID microscope (Magnetic Microscope). The present invention particularly relates to a manufacturing method of a SQUID combination module and its magnetic probe for a scanning SQUID microscope, and simultaneously relates to the application of a scanning SQUID microscope and a method for detecting defects in integrated circuit chips. Background Art

[0002] In recent years, due to the excellent spatial and magnetic field resolution and the inherent advantages of passive non-destructive detection of superconducting quantum interference devices, and at the same time with the development of integrated circuit technology, the magnetic scanning SQUID microscope (SSM) technology using SQUID chips to detect the magnetism of samples has attracted more and more researchers' interest.

[0003] Among current magnetic microscopes, the scanning SQUID microscope is the most sensitive due to its high spatial resolution and magnetic field resolution. The superconducting quantum interference device (Superconducting Quantum Interference Device, SQUID), as the most sensitive current magnetic field detection device, can detect weak magnetic fields at the picotesla (pT) level and has been widely used in many fields such as biomagnetism and physical science research. However, in the detection of defects in integrated circuit chips, the existing SQUID systems still have problems of insufficient spatial resolution and low signal coupling rate.

[0004] Recently, internationally, research institutions such as the Forschungszentrum Jülich in Germany, the University of Basel in Switzerland, and the Hebrew University in Israel have used nano SQUIDs to achieve nanoscale spatial resolution of cryogenic samples. Domestically, the Shanghai Institute of Microsystem and Information Technology, Fudan University, Nanjing University, and Shanghai Jiao Tong University in the Chinese Academy of Sciences have also achieved a breakthrough in 100 nm resolution based on nano SQUIDs of dozens of nm. However, the above high-resolution systems are based on cryogenic SQUID technology in the 4.2K liquid helium temperature range, and the scanned samples also need to be placed in a vacuum chamber. Due to the limitation of the vacuum system, the application of integrated circuits operating at room temperature is restricted. Moreover, the sensitivity of SQUID is proportional to the inductance area. When integrated circuits work, the magnetic field is only in the pT - μT magnitude range, while the sensitivity of nano-SQUID is in the nT magnitude range, making it difficult to effectively cover.

[0005] When an integrated circuit is operating, the current can be equivalent to a magnetic field source, which is isolated from the SQUID chip by a vacuum system, and the magnetic signal decays exponentially with distance. By introducing a probe with high magnetic permeability, the coupling rate of the magnetic signal can be increased; and through the design of the probe tip, high spatial resolution can be achieved. Combining the magnetic probe with the low-noise characteristics of the mm-level SQUID, high-sensitivity magnetic signal detection can be realized. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a manufacturing method of a SQUID combination module for a scanning SQUID magnetic microscope and its magnetic probe, and at the same time provide a method for defect detection of integrated circuit chips using a scanning SQUID magnetic microscope.

[0007] To solve the above technical problem, the technical solution of a SQUID combination module for a scanning SQUID magnetic microscope of the present invention is as follows:

[0008] A SQUID combination module for a scanning SQUID magnetic microscope includes a SQUID chip. It is characterized in that on one side of the SQUID chip that does not contain the flux induction junction region, a permalloy thin sheet is pasted with low-temperature glue; on one side of the SQUID chip that contains the flux induction junction region, a magnetic probe is pasted with low-temperature glue, so that the magnetic probe is at the physical center of the receiving coil of the SQUID and far from the flux induction junction region of the SQUID. The inner core of the magnetic probe is a solid quartz needle in the shape of a cone cylinder. Permalloy films are sputter-deposited on the side surface and the bottom surfaces at both ends of the solid quartz needle, and after the sputter deposition of the permalloy films is completed, a laser cutting process is used to perform multiple high-precision cutting processes on the tip and the tail end of the magnetic probe to complete.

[0009] A further technical solution of a SQUID combination module for a scanning SQUID magnetic microscope of the present invention is as follows:

[0010] The permalloy thin sheet has the same area as the SQUID chip and a thickness of 100 μm. The thickness of the low-temperature glue paste layer after pasting the permalloy thin sheet and the SQUID chip does not exceed 10 μm, and the thickness of the low-temperature glue paste layer after pasting the magnetic probe and the SQUID chip does not exceed 1 μm.

[0011] The overall total length of the magnetic probe is 2-4 mm, which is divided into a needle column part in the shape of a cylinder and a tip part in the shape of a cone. The tip part is designed with an axial gradient structure, and the diameter gradually transitions from 500 nm-600 nm at the tip to 500 μm-600 μm at the tail.

[0012] The tip cone angle of the quartz rod is 10° - 15°, the diameter is 100 nm - 200 nm, and the length is 1 mm - 2 mm; the tail diameter is 50 μm - 100 μm, and the length is 1 mm - 2 mm; the inner core solid quartz needle is wrapped with permalloy, and the permalloy film on the outer side of the tip gradually changes from the tip to the tail end of the tip in a range of 0.2 μm - 200 μm, and the permalloy film thickness on the outer side of the tail is 200 μm - 300 μm; the permalloy film thickness at the tip surface and the tail surface of the quartz needle body is 1 μm - 3 μm; the permalloy film thickness at the lower surface of the tip of the solid quartz needle body and the upper surface of the tail is 1 μm - 3 μm.

[0013] To solve the above technical problems, the technical solution of the method for manufacturing the magnetic probe of the present invention is:

[0014] The method for manufacturing the magnetic probe of the present invention is characterized by including the manufacture of a solid quartz needle, the sputtering deposition treatment of permalloy on the solid quartz needle, and the use of high-precision laser processing technology to perform multiple cuts on the magnetic probe.

[0015] A further technical solution of the method for manufacturing the magnetic probe of the present invention is:

[0016] First, select a quartz rod with a diameter of 200 μm and a length of 2 cm, and use a needle puller to pull the quartz rod to form a geometric shape with a tip diameter of 100 - 200 nm, a tail diameter of 200 μm, and a total length of the conical tip of 1 - 2 mm, and retain a cylindrical part of 1 - 2 mm above the cone as the needle tail. The excess part is melted at high temperature and polished with sandpaper to ensure a smooth surface; install the processed solid quartz needle body on the sputtering bracket and place it in the deposition chamber; use a permalloy cylinder as the target to sputter the outer surface of the solid quartz needle, and a permanent magnet ring and a magnetic yoke are equipped around it to provide a stable magnetic field; at the same time, a negative bias voltage is applied to the cathode and the anode is grounded to form an electric field, so as to realize the sputtering deposition process from the outside to the inside; after closing the deposition chamber, start the vacuum pump group to reduce the air pressure in the chamber to 0.5×10 -4 Pa to improve the sputtering efficiency and film quality; when the vacuum degree reaches the set requirement, accurately control the argon flow through a gas mass flowmeter and introduce an appropriate amount of argon; under the combined action of the electric field and the magnetic field, electrons move in a spiral near the target surface, enhancing the ionization effect of argon to form a high-density plasma ring; argon ions bombard the permalloy target, causing the target atoms to sputter onto the surface of the magnetic probe workpiece, thereby forming a uniform permalloy film on the outer surface of the quartz needle to achieve centripetal sputtering deposition; after the sputtering deposition is completed, use high-precision laser processing technology to perform multiple cuts on the magnetic probe.

[0017] The deposition process is carried out in two stages: The first stage: The solid quartz needle body is installed parallel to the cylindrical target and fixed on a sputtering bracket with axial movement function, so that the needle body rotates axially during the deposition process to ensure uniform deposition of a Permalloy film with a thickness of 250 μm on the tip side surface and the cylindrical side surface of the solid quartz needle body; The second stage: Readjust the placement direction of the quartz needle body so that it is fixed perpendicular to the cylindrical target on the sputtering bracket, and further deposit a Permalloy film with a thickness of 1 - 3 μm in the tip and tail regions to optimize the performance of the magnetic probe.

[0018] During the process of cutting the magnetic probe multiple times, by precisely controlling the cutting process, the cross-section of the magnetic probe successively presents forms such as a rounded rectangle and an octagon; As the number of cutting times increases, the cross-section of the magnetic probe tends to be circular; This optimization process realizes a gradual change in the thickness of the Permalloy film between 0.2 μm and 200 μm, which helps to improve the surface structure and magnetic properties of the magnetic probe and enables it to meet the requirements of high-precision applications.

[0019] The magnetic probe of the present invention is made by the manufacturing method described above.

[0020] The scanning SQUID microscope of the present invention includes a Dewar, a cold finger, and a SQUID combination module as described above.

[0021] The scanning SQUID microscope is used for defect detection of integrated circuit chips.

[0022] To solve the above technical problems, the technical solution of the scanning SQUID microscope of the present invention for the method of defect detection of integrated circuit chips is:

[0023] Place the magnetic probe and the SQUID chip combination module in a cryogenic Dewar to build a cryogenic environment of 77 Kelvin to maintain the superconducting normal working state of the SQUID chip; After electrically connecting the combination module to the test rod, externally connect the readout circuit and signal reading device required for magnetic detection, and place a high-precision stepping motor below the Dewar. Place the integrated circuit chip under test in the fixed device of the stepping motor. Control the displacement of the integrated circuit chip through the stepping motor, align the magnetic probe with the corresponding part of the integrated circuit chip under test, and enable the magnetic probe and the SQUID chip combination module to detect the magnetic field generated by the weak current on the internal wiring of the integrated circuit chip, realizing the magnetic detection of the weak current inside the integrated circuit chip.

[0024] The beneficial effects of the present invention are as follows: The present invention uses the magnetron sputtering coating technology to deposit a Permalloy material with high magnetic permeability on the quartz needle body, and then prepares a magnetic probe based on Permalloy. After using the magnetic probe, the signal coupling rate during detection can be increased while ensuring a sub-micron spatial resolution.

[0025] The present invention is a technology worthy of popularization in the field of chip detection technology. The beneficial effects of the present invention are as follows: The present invention uses the magnetron sputtering coating technology to deposit permalloy materials with high magnetic permeability on the quartz needle body, and then prepares a magnetic probe based on permalloy. After using the magnetic probe, the signal coupling rate during detection can be increased while ensuring a sub-micron spatial resolution. Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the SQUID combination module of the present invention;

[0027] Figure 2 It is a schematic diagram of the model for the spatial resolution simulation test of the SQUID combination module of the present invention;

[0028] Figure 3 It is a schematic diagram of the technical solution for the preparation of the magnetic probe;

[0029] Figure 4 It is a schematic cross-sectional view of the magnetron sputtering device when preparing the surface film of the magnetic probe by the magnetron sputtering technology;

[0030] Figure 5 It is a schematic diagram of the process flow for machining the conical tip and the tail end part of the magnetic probe multiple times;

[0031] Figure 6 It is a front view schematic diagram of the installation state of the SQUID combination module;

[0032] Figure 7 It is a top view schematic diagram of the installation state of the SQUID combination module;

[0033] Figure 8 It is a schematic diagram of the magnetic flux density streamline obtained by the simulation detection of the magnetic probe;

[0034] Figure 9 It is a schematic diagram of the test result of the spatial resolution simulation test of the magnetic probe.

[0035] The above-mentioned drawings are all schematic and do not correspond to the actual ratio. Some parts are exaggerated.

[0036] The parts indicated by the reference numerals in each figure are: 1. SQUID chip; 2. Low-temperature adhesive; 3. Permalloy thin sheet; 4. Permalloy thin sheet; 5. Solid quartz needle; 6. Permalloy film; 7. Needle column part; 8. Tip part; 9. Sputtering bracket; 10. Upper fastener; 11. Cold finger; 12. Lower fastener; 13. Connecting arm. Detailed Embodiment

[0037] The present invention will be further described in detail below with reference to the drawings.

[0038] The SQUID combination module of the present invention for scanning SQUID magnetic microscopes, such as Figure 1 shown, includes a SQUID chip 1. On one side of the SQUID chip 1 that does not contain the flux induction junction region, a permalloy thin sheet 3 is pasted with cryogenic adhesive 2; on the side of the SQUID chip 1 that contains the flux induction junction region, a magnetic probe 4 is pasted with cryogenic adhesive 2, so that the magnetic probe 4 is at the physical center of the receiving coil of the SQUID as far as possible from the flux induction junction region of the SQUID. The inner core of the magnetic probe 4 is a solid quartz needle 5 with a conical cylinder shape. On the side surface and the bottom surfaces at both ends of the solid quartz needle 5, a permalloy film 6 is sputter-deposited. After the sputter deposition of the permalloy film 6 is completed, a laser cutting process is used to perform multiple high-precision cutting processes on the tip and the tail end parts of the magnetic probe 4 to complete. The flux induction junction is also called the Josephson junction.

[0039] As Figure 1 shown, the permalloy thin sheet 3 has the same area as the SQUID chip 1 and a thickness of 100 μm. The thickness of the cryogenic adhesive layer after pasting the permalloy thin sheet 3 and the SQUID chip 1 does not exceed 10 μm, and the thickness of the cryogenic adhesive layer after pasting the magnetic probe 4 and the SQUID chip 1 does not exceed 1 μm.

[0040] As Figure 1 、 Figure 2 shown, the overall total length of the magnetic probe 4 is 2 - 4 mm, including a needle column part 7 in the shape of a cylinder and a tip part 8 in the shape of a cone. The diameter of the tip part 8 gradually transitions from 500 nm - 600 nm at the tip to 500 μm - 600 μm at the tail.

[0041] As Figure 1 、 Figure 2 shown, the tip cone angle of the tip part 8 of the solid quartz needle 5 is 10° - 15°, the diameter is 100 nm - 200 nm, and the length is 1 mm - 2 mm; the diameter of the tail is 50 μm - 100 μm, and the length is 1 mm - 2 mm; the outside of the inner core solid quartz needle 5 is wrapped with permalloy. After the permalloy film 6 on the outside side of the tip part 8, it gradually changes from 0.2 μm - 200 μm from the tip of the tip to the tail of the tip. The thickness of the permalloy film 6 on the outside side of the tail is 200 μm - 300 μm; the thickness of the permalloy film 6 on the tip surface and the tail surface of the quartz needle body is 1 μm - 3 μm; the thickness of the permalloy film 6 on the lower surface of the tip of the solid quartz needle 5 and the upper surface of the tail is 1 μm - 3 μm.

[0042] The manufacturing method of the magnetic probe 4 of the present invention includes the manufacturing of the solid quartz needle 5, the sputter deposition treatment of the permalloy on the solid quartz needle 5, and the use of high-precision laser processing technology to perform multiple cuts on the magnetic probe 4.

[0043] The specific manufacturing steps of the magnetic probe 4 of the present invention are as follows Figure 3 As shown, first, a quartz rod with a diameter of 200 μm and a length of 2 cm is selected, and the quartz rod is drawn using a needle puller. Currently, both the above-mentioned quartz rod and the needle puller are commercially available. It is formed into a geometric shape with a tip diameter of 100 - 200 nm, a tail diameter of 200 μm, and a total conical tip length of 1 - 2 mm, and a cylindrical part of 1 - 2 mm above the cone is reserved as the needle tail. The excess part is melted at high temperature and polished with sandpaper to ensure a smooth surface.

[0044] The sputter deposition treatment of the permalloy on the solid quartz needle 5 can be carried out in a magnetron sputtering device as shown Figure 4 As shown. Currently, such a magnetron sputtering device is commercially available.

[0045] As Figure 4 shown, the processed solid quartz needle 5 body is installed on the sputtering bracket 9 of the magnetron sputtering device as shown Figure 4 and placed in its deposition chamber. The permalloy cylinder is used as the target to sputter the outer surface of the solid quartz needle 5, and a permanent magnet ring and a magnetic yoke are equipped around it to provide a stable magnetic field. At the same time, a negative bias voltage is applied to the cathode and the anode is grounded to form an electric field, thereby realizing the sputter deposition process from the outside to the inside. After closing the deposition chamber, start the vacuum pump group to reduce the air pressure in the chamber to 0.5×10 -4 Pa to improve the sputtering efficiency and film quality; when the vacuum degree reaches the set requirement, accurately control the argon flow through a gas mass flowmeter and introduce an appropriate amount of argon. Under the combined action of the electric field and the magnetic field, electrons move in a spiral near the surface of the target, enhancing the ionization effect of argon and forming a high-density plasma ring; argon ions bombard the permalloy target, causing the target atoms to sputter onto the surface of the magnetic probe 4 workpiece, thereby forming a uniform permalloy film on the outer surface of the quartz needle and realizing centripetal sputter deposition. After the sputter deposition is completed, the magnetic probe 4 is cut multiple times using high-precision laser processing technology.

[0046] The deposition process is carried out in two stages: The first stage: The solid quartz needle 5 body is installed parallel to the cylindrical target and fixed on the sputtering bracket 9 with an axial movement function, and the needle body rotates axially during the deposition process to ensure a uniform deposition of a 250-μm-thick permalloy film on the tip side surface and the cylindrical side surface of the solid quartz needle 5 body; The second stage: Readjust the placement direction of the quartz needle body so that it is perpendicular to the cylindrical target and fixed on the sputtering bracket 9, and further deposit a 1 - 3-μm-thick permalloy film in the tip and tail regions to optimize the performance of the magnetic probe 4.

[0047] During the process of cutting the magnetic probe 4 multiple times, by precisely controlling the cutting process, the cross-section of the magnetic probe 4 successively presents shapes such as a rounded rectangle and an octagon; as Figure 5As shown, as the number of cutting times accumulates, the cross-section of the magnetic probe 4 tends to be circular; this optimization process realizes the gradual distribution of the thickness of the permalloy thin film between 0.2 μm and 200 μm, which helps to improve the surface structure and magnetic properties of the magnetic probe 4, enabling it to meet the requirements of high-precision applications.

[0048] The magnetic probe 4 of the present invention is fabricated by the manufacturing method as described above.

[0049] A scanning SQUID microscope includes a dewar and a cold finger, and also includes the above-mentioned SQUID combination module. It can be used for defect detection of integrated circuit chips.

[0050] For the method of using the above scanning SQUID microscope for defect detection of integrated circuit chips, the magnetic probe 4 and the SQUID chip 1 combination module are placed in a cryogenic dewar to construct a cryogenic environment of 77 Kelvin to maintain the superconducting normal working state of the SQUID chip 1; after the combination module is electrically connected to the test rod, an external readout circuit and signal reading device required for magnetic detection are connected, and a high-precision stepping motor is placed under the dewar, and the integrated circuit chip under test in the energized state is placed on the fixing device of the stepping motor. The displacement of the integrated circuit chip is controlled by the stepping motor to align the magnetic probe 4 with the corresponding part of the integrated circuit chip to be tested, so that the magnetic probe 4 and the SQUID chip 1 combination module detect the magnetic field generated by the weak current on the internal trace of the integrated circuit chip, realizing the magnetic detection of the weak current inside the integrated circuit chip. Among them, the installation of the SQUID combination module is as Figure 6 、 Figure 7 shown, and a connecting piece is used to realize the fixed connection between the magnetic probe 4 and the cold finger 11. In this connection system, the connecting piece includes two upper and lower fasteners. The upper fastener 10 is fixedly connected to the cold finger 11 of the SQUID system, and the lower fastener 12 fixes the magnetic probe 4. The specific connection method is that a screw passes through the threaded through hole of the upper fastener 10 and is tightened with a nut to firmly clamp the upper fastener 10 and the cold finger 11. After the above operations are completed, the reliable connection between the cold finger 11 and the magnetic probe 4 can be realized. The two upper and lower fasteners are connected into a whole through a connecting arm 13.

[0051] The magnetic flux density streamline diagram obtained by simulating and detecting using the SQUID combination module of the present invention is as Figure 8 shown. The test results of the spatial resolution simulation test using the SQUID combination module of the present invention are as Figure 9 shown.

Claims

1. A SQUID combination module for a scanning SQUID magnetic microscope, including a SQUID chip (1), characterized in that, On one side of the SQUID chip (1) that does not contain the flux induction junction area, a Permalloy thin sheet (3) is adhered by low-temperature glue (2); on the side of the SQUID chip (1) that contains the flux induction junction area, a magnetic probe (4) is adhered by low-temperature glue (2), so that the magnetic probe (4) is at the physical center of the receiving coil of the SQUID chip (1) away from the flux induction junction area of the SQUID. The inner core of the magnetic probe (4) is a solid quartz needle (5) in the shape of a conical cylinder. On the side surface and the bottom surfaces at both ends of the solid quartz needle (5), a Permalloy film (6) is sputter-deposited, and after the sputter deposition of the Permalloy film (6) is completed, a laser cutting process is used to perform multiple high-precision cutting processes on the tip and tail parts of the magnetic probe (4) to complete it.

2. The SQUID combination module according to claim 1, characterized in that, The Permalloy thin sheet (3) has the same area as the SQUID chip (1) and a thickness of 100 μm. The thickness of the low-temperature glue (2) adhesive layer after the Permalloy thin sheet (3) is adhered to the SQUID chip (1) does not exceed 10 μm, and the thickness of the low-temperature glue (2) adhesive layer after the magnetic probe (4) is adhered to the SQUID chip (1) does not exceed 1 μm.

3. The SQUID combination module according to claim 1, wherein, The overall total length of the magnetic probe (4) is 2 - 4 mm, including a needle column part (7) in the shape of a cylinder and a tip part (8) in the shape of a cone. The diameter of the tip part (8) gradually transitions from 500 nm - 600 nm at the tip to 500 μm - 600 μm at the tail.

4. The SQUID combination module according to claim 3, wherein, The tip cone angle of the tip part (8) of the solid quartz needle (5) is 10° - 15°, the diameter is 100 nm - 200 nm, and the length is 1 mm - 2 mm; the diameter of the tail is 50 μm - 100 μm, and the length is 1 mm - 2 mm; it is wrapped with Permalloy outside the inner core solid quartz needle (5). The Permalloy film (6) on the outer side surface of the tip part (8) gradually changes from 0.2 μm - 200 μm from the tip of the needle to the tail of the tip, and the thickness of the Permalloy film (6) on the outer side surface of the tail is 200 μm - 300 μm; the thickness of the Permalloy film (6) on the tip surface and the tail surface of the quartz needle body is 1 μm - 3 μm; the thickness of the Permalloy film (6) on the lower surface of the tip of the solid quartz needle (5) and the upper surface of the tail is 1 μm - 3 μm.

5. The manufacturing method of the magnetic probe (4) according to claim 1, characterized in that, It includes the production of the solid quartz needle (5), the sputter deposition treatment of the Permalloy on the solid quartz needle (5), and the use of high-precision laser processing technology to perform multiple cuts on the magnetic probe (4).

6. The manufacturing method of the magnetic probe (4) according to claim 1, characterized in that, First, select a quartz rod with a diameter of 200 μm and a length of 2 cm, and use a needle puller to draw the quartz rod to form a geometric shape with a tip diameter of 100 - 200 nm, a tail diameter of 200 μm, and a total conical tip length of 1 - 2 mm. Retain a 1 - 2 mm cylindrical part above the cone as the needle tail, and grind the excess part with sandpaper after high - temperature fusing to ensure a smooth surface; install the processed solid quartz needle (5) body onto the sputtering bracket and place it in the deposition chamber; use a permalloy cylinder as the target to sputter the outer surface of the solid quartz needle (5), and equip a permanent magnet ring and a magnetic yoke around it to provide a stable magnetic field; at the same time, apply a negative bias voltage to the cathode and ground the anode to form an electric field, thus realizing the sputtering deposition process from the outside to the inside; after closing the deposition chamber, start the vacuum pump group to reduce the chamber pressure to 0.5×10 -4 Pa to improve the sputtering efficiency and film quality; when the vacuum degree reaches the set requirement, precisely control the argon flow rate through a gas mass flowmeter and introduce an appropriate amount of argon; under the combined action of the electric field and the magnetic field, electrons move in a spiral near the surface of the target, enhancing the ionization effect of argon to form a high - density plasma ring; argon ions bombard the permalloy target, causing the target atoms to sputter onto the surface of the workpiece, thus forming a uniform permalloy thin film on the outer surface of the quartz needle and realizing centripetal sputtering deposition; After the sputter deposition is completed, high-precision laser processing technology is used to perform multiple cuts on the magnetic probe (4).

7. The manufacturing method of the magnetic probe (4) according to claim 6, characterized in that, The deposition process is carried out in two stages: The first stage: The solid quartz needle (5) body is installed parallel to the cylindrical target and fixed on a sputtering bracket with axial movement function, so that the needle body rotates axially during the deposition process to ensure uniform deposition of a Permalloy thin film with a thickness of 250 μm on the tip side surface and the cylindrical side surface of the solid quartz needle (5) body; The second stage: Readjust the placement direction of the quartz needle body so that it is fixed perpendicular to the cylindrical target on the sputtering bracket, and further deposit a Permalloy thin film with a thickness of 1 - 3 μm in the tip and tail regions to optimize the performance of the magnetic probe (4).

8. The manufacturing method of the magnetic probe (4) according to claim 6, characterized in that, In the process of performing multiple cuts on the magnetic probe (4), by precisely controlling the cutting process, the cross-section of the magnetic probe (4) successively presents forms such as a rounded rectangle and an octagon; As the number of cuts increases, the cross-section of the magnetic probe (4) tends to be circular; This optimization process realizes a gradual change in the thickness of the Permalloy thin film between 0.2 μm and 200 μm, which helps to improve the surface structure and magnetic properties of the magnetic probe (4) and enables it to meet the requirements of high-precision applications.

9. The magnetic probe (4) according to claim 1, wherein, It is made by the manufacturing method according to any one of claims 5 to 8.

10. A scanning SQUID magnetic microscope, comprising a dewar, a cold finger and a SQUID combination module according to any one of claims 1 to 5.

11. The scanning SQUID magnetic microscope according to claim 10, which is used for defect detection of integrated circuit chips.

12. The method for using the scanning SQUID magnetic microscope according to claim 10 for defect detection of integrated circuit chips. The magnetic probe (4) and the SQUID chip (1) combination module are placed in a cryogenic dewar to construct an ultra-low temperature environment of 77 Kelvin to keep the SQUID chip (1) in a superconducting normal working state; After electrically connecting the combination module to the test rod and externally connecting the readout circuit and signal reading device required for magnetic detection, and placing a high-precision stepping motor under the dewar, the integrated circuit chip under test in the energized state is placed on the fixing device of the stepping motor. The displacement of the integrated circuit chip is controlled by the stepping motor to align the magnetic probe (4) with the corresponding part of the integrated circuit chip under test, so that the magnetic probe (4) and the SQUID chip (1) combination module detect the magnetic field generated by the weak current on the internal wiring of the integrated circuit chip, realizing the magnetic detection of the weak current inside the integrated circuit chip.

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