Chip surface three-dimensional space near-field magnetic field confocal rapid measurement device based on diamond nv color center

Abstract

The application discloses a kind of chip surface three-dimensional space near-field magnetic field confocal fast measuring device based on diamond NV color center, it is related to magnetic field measurement technical field, comprising: excitation light path component, microwave control component, fluorescence acquisition detection component, diamond NV color center sensing unit, three-dimensional displacement driving component and main control unit.Main control unit timing linkage each module, 532nm laser is excited NV color center after being split, modulated, confocal, microwave controls quantum state, and fluorescence signal is collected to solve magnetic field;Rely on three-dimensional displacement table global scanning to realize three-dimensional magnetic field mapping.The application has the characteristics of non-contact nondestructive testing, submicron resolution, room temperature available, high measurement sensitivity, and is suitable for high-frequency chip electromagnetic compatibility detection.

Description

Technical Field

[0001] This invention relates to the field of magnetic field measurement technology, and more specifically to a rapid confocal measurement device for near-field magnetic fields on a chip surface based on diamond NV color centers. Background Technology

[0002] Traditional weak magnetic field measurements mainly rely on conventional magnetic field sensing principles such as electromagnetic induction and the Hall effect. With the iterative development of 5G and ultra-high frequency band communication technologies, the mainstream operating frequency bands of integrated circuits continue to rise; at the same time, the high-stack architecture of chips and advanced manufacturing processes place higher demands on the spatial resolution of magnetic field measurements, and traditional measurement methods are no longer adequate for current testing needs in terms of operating frequency domain and spatial resolution.

[0003] Diamond NV center (NVC) magnetic field measurement technology represents a new generation of quantum sensing solutions, opening up new avenues for near-field magnetic field detection in chips. This technology relies on the coupled interactions of magnetism, light, and atomic spins to achieve magnetic field detection. Compared to traditional methods, it offers a significant improvement in detection sensitivity, boasts high spatial resolution and wide measurement bandwidth, and the measurement results are traceable to quantum benchmarks, enabling self-calibration testing. However, current chip near-field magnetic field testing using diamond NV centers relies solely on single-point reciprocating scanning or multi-region image stitching to obtain the two-dimensional near-field magnetic field distribution on the chip surface. It does not yet support simultaneous three-dimensional near-field magnetic field measurement across the entire chip area, highlighting a significant limitation of the existing technology.

[0004] Therefore, how to break through the bottleneck of existing chip near-field magnetic field measurement technology and fill the technical gap in synchronous and rapid detection of chip near-field three-dimensional magnetic field is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a rapid measurement device for near-field magnetic field confocalization on the surface of a chip based on diamond NV color centers, which solves the problems existing in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A rapid measurement device for near-field magnetic field confocalization on the surface of a chip based on diamond NV centers includes: an excitation optical path assembly, a microwave control assembly, a fluorescence acquisition and detection assembly, a diamond NV center sensing unit, a three-dimensional displacement driving assembly, and a main control unit; The laser emission optical path of the excitation optical path assembly is aligned with the diamond NV color center sensing unit to generate and output modulated excitation laser; The microwave control component is electrically connected to the diamond NV color center sensing unit to provide the control microwave signal; The fluorescence acquisition and detection component is arranged on the fluorescence output side of the excitation optical path component to receive the fluorescence signal emitted by the stimulated emission of the diamond NV color center sensing unit. The diamond NV color center sensing unit is fixedly mounted on the three-dimensional displacement drive assembly and driven by the three-dimensional displacement drive assembly to perform a three-dimensional spatial scan relative to the chip under test. The main control unit is electrically connected to the excitation optical path assembly, microwave control assembly, fluorescence acquisition and detection assembly, and three-dimensional displacement drive assembly, respectively, and is used to perform full device timing coordination control, detection signal acquisition, and data processing.

[0007] Optionally, the excitation optical path assembly is arranged sequentially along the laser propagation direction as follows: laser, first polarizer, PBS energy beam splitter, front plano-concave mirror, acousto-optic modulator, rear plano-concave mirror, second polarizer, first aperture stop, mirror, aperture, dichroic mirror, and first flat achromatic objective lens; the second aperture stop is provided in the reflected reference calibration beam branch split by the PBS energy beam splitter. The laser output from the laser first passes through a first polarizer for polarization screening before entering a PBS energy beam splitter. The PBS energy beam splitter splits the incident laser into a transmitted beam and a reflected beam with a 50:50 energy ratio. The transmitted beam, as the main measurement beam, enters a front plano-concave mirror, while the reflected beam, as a reference calibration beam, passes through a second aperture stop and is then led out to calibrate the optical path reference. The transmitted beam is expanded and collimated by the front plano-concave mirror before entering an acousto-optic modulator to complete laser modulation. The modulated beam is then collimated and shaped a second time by a rear plano-concave mirror. The shaped beam passes through a second polarizer and a first aperture stop in sequence to complete beam aperture limitation and secondary polarization screening, resulting in a collimated polarized beam. The collimated polarized beam is deflected by a reflector and then passes through a light-transmitting aperture before entering a dichroic mirror. The transmitted beam from the dichroic mirror is focused by a first flat-field achromatic objective and enters the interior of the diamond NV color center sensing unit.

[0008] Optionally, the microwave control components include: a microwave generator, a power amplifier, a microwave switch, and a microwave antenna; The microwave signal output by the microwave generator is selected by a microwave switch and then sent to a power amplifier for power amplification. The amplified microwave signal is coupled to the diamond NV color center sensing unit via a microwave antenna to achieve internal NV color center quantum state control.

[0009] Optionally, the fluorescence acquisition and detection components include: a filter, a second flat achromatic objective lens, an APD avalanche photodetector, and a lock-in amplifier; The fluorescence emitted by the stimulated emission of the diamond NV color center sensing unit passes sequentially through the first flat achromatic objective lens and a filter to remove stray light before being incident on a dichroic mirror. The fluorescence is reflected by the dichroic mirror and then passes through the second flat achromatic objective lens before being incident on the APD avalanche photodetector. The APD avalanche photodetector converts the optical signal into an electrical signal and transmits it to a lock-in amplifier to complete the signal noise reduction and amplification process.

[0010] Optionally, the diamond NV color center sensing unit includes: a bulk diamond NV color center cube and a permanent magnet; Permanent magnets are mounted on the sides of a bulk diamond NV color center cube to apply a static bias magnetic field to the internal NV color center. The bulk diamond NV color center cube serves as the core of the optical-magnetic coupling detection, connecting to the light-emitting end of the excitation optical path component and the microwave antenna of the microwave control component, respectively.

[0011] Optionally, the three-dimensional displacement drive components include: an electrically controlled three-dimensional displacement stage and an electrically controlled displacement stage control box; The diamond NV color center sensing unit is fixed to the electronically controlled three-dimensional displacement stage. The electronically controlled displacement stage control box receives instructions from the main control unit and drives the electronically controlled three-dimensional displacement stage to perform three-dimensional movement along the X / Y / Z axes, so that the diamond NV color center sensing unit can perform confocal three-dimensional near-field magnetic field scanning.

[0012] Optionally, the main control unit includes: a multi-channel arbitrary waveform generator and a computer; the computer sends control commands to the multi-channel arbitrary waveform generator, and the multi-channel arbitrary waveform generator outputs multiple synchronous timing signals to perform synchronous timing control on the excitation optical path component, microwave control component, fluorescence acquisition and detection component, and three-dimensional displacement drive component, respectively. The electrical signals acquired by the fluorescence acquisition and detection component are transmitted back to the computer to complete data processing.

[0013] Optionally, an electromagnetic shielding cover is also provided, and the dichroic mirror, filter, first flat achromatic objective lens, second flat achromatic objective lens, and APD avalanche photodetector are all arranged inside the electromagnetic shielding cover.

[0014] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a rapid measurement device for three-dimensional near-field magnetic field confocalization on the chip surface based on diamond NV color centers, which has the following beneficial effects: (1) This invention breaks through the technical limitation that traditional chip magnetic fields can only be tested in two-dimensional planes. It relies on a three-dimensional displacement drive component to carry a diamond NV color center sensing unit to complete spatial layer scanning, realize the rapid measurement of the three-dimensional near-field magnetic field of the chip surface, and can completely collect and restore the three-dimensional spatial distribution data of the chip's electromagnetic radiation, enriching the dimensions of chip magnetic field characterization.

[0015] (2) The device relies on the quantum sensing mechanism of diamond NV color center to carry out magnetic field detection. Compared with traditional detection schemes such as Hall sensor and electromagnetic induction probe, the magnetic field detection sensitivity is greatly improved. It can accurately capture the weak near-field magnetic field signal on the chip surface and is suitable for the detection scenarios of chip micro leakage magnetic field and local micro-area magnetic field.

[0016] (3) This solution adopts optical non-contact detection, with no metal measuring probe extending into the chip area to be tested. This avoids parasitic electromagnetic coupling interference between the metal probe and the chip under test from the source, eliminates additional interference noise, and effectively ensures the authenticity and accuracy of magnetic field measurement data.

[0017] (4) The overall measurement process is non-invasive, non-contact, and non-destructive optical detection. The testing process will not scratch or damage the chip wafer and internal circuit structure, nor will it interfere with the original normal working state of the chip. It is especially suitable for on-chip in-situ detection of advanced high-precision chips.

[0018] (5) Diamond NV color centers can stably complete quantum state control and magnetic field detection in a normal room temperature environment without the need for a low temperature refrigeration unit, saving the investment in low temperature supporting equipment and significantly reducing the hardware construction cost and long-term operating energy consumption of the entire measurement equipment.

[0019] (6) The device is equipped with a confocal optical path, and the excited laser is precisely focused to the diamond NV color center measurement point through a multi-level lens to achieve sub-micron level spatial resolution, which meets the application requirements of high-resolution magnetic field imaging of micro-area of ​​advanced process nanoscale chips.

[0020] (7) The present invention is equipped with a wide-band microwave control component, which has a wide measurement frequency coverage and is compatible with the near-field magnetic field calibration and testing of 5G radio frequency chips and next-generation ultra-high frequency integrated circuits, and has a wider range of applications.

[0021] (8) Based on the inherent physical properties of the NV color center quantum energy level, the measurement results can be directly traced to the quantum reference. The device has built-in self-calibration capability, which effectively solves the long-term instrument drift problem and ensures the data stability and result consistency of long-term continuous measurement.

[0022] (9) By combining the three-axis precision drive of the electronically controlled three-dimensional displacement stage with the co-focusing optical path fixed-point acquisition, the full-area automated rapid scanning imaging of the chip under test is realized, the full-domain magnetic field data acquisition cycle is shortened, and the characterization and testing efficiency of the chip's three-dimensional magnetic field is effectively improved.

[0023] (10) The high-precision three-dimensional magnetic field distribution data output by this device can be directly used for chip electromagnetic interference fault tracing, EMC electromagnetic compatibility optimization and iteration, chip electrical performance assessment and product reliability verification, shortening the chip R&D and testing cycle and helping integrated circuit products to iterate and upgrade. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 A schematic diagram of a partial structure of the back-end optical path of the acousto-optic modulator provided by the present invention; Figure 2 The waveform diagram for synchronous timing control of multiple devices in the whole machine provided by the present invention; Figure 3 This is a partial optical path diagram of the excitation optical path assembly and the fluorescence acquisition and detection assembly provided by the present invention; Figure 4 A schematic diagram of the assembly structure of the bulk diamond NV color center cube and the plan achromatic objective lens provided by the present invention; Figure 5 The overall structure diagram of the chip surface three-dimensional near-field magnetic field confocal rapid measurement device based on diamond NV color centers provided by the present invention; Figure reference numerals: 1-Laser, 2-PBS energy beam splitter, 3-Acousto-optic modulator, 4-Front plano-concave mirror, 5-Reflector, 6-Rear plano-concave mirror, 7-First aperture stop, 8-Dichroic mirror, 9-Filter, 10-First plan achromatic objective lens, 11-First polarizer, 12-Second polarizer, 13-APD avalanche photodetector, 14-Bulk diamond NV color center cube, 15-Lock-in amplifier, 16-Microwave generator, 17-Power amplifier, 18-Multi-channel arbitrary waveform generator, 19-Computer, 20-Electrically controlled three-dimensional displacement stage, 21-Electrically controlled displacement stage control box, 22-Microwave switch, 23-Electromagnetic shield, 24-Second aperture stop, 25-Communication cable, 26-Second plan achromatic objective lens, 27-Microwave antenna, 28-Permanent magnet, 29-Cage rod. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Currently, methods for measuring and characterizing the three-dimensional near-field magnetic field on chip surfaces still have significant technical limitations. Existing conventional techniques can only achieve single-layer measurements of the near-field magnetic field on a two-dimensional plane of the chip surface, failing to achieve three-dimensional acquisition and complete characterization of the chip's near-field magnetic field information across the entire domain. Chip near-field electromagnetic radiation emission exhibits typical three-dimensional spatial distribution characteristics. Relying solely on two-dimensional magnetic field measurement data is insufficient to comprehensively and accurately reflect the chip's global electromagnetic radiation emission characteristics and actual electromagnetic compatibility (EMC) conditions. It cannot fully reconstruct the chip's electromagnetic field coupling characteristics, thus leading to a lack of data support for chip performance analysis, electromagnetic interference tracing, and EMC optimization design.

[0028] To overcome the limitations of existing near-field magnetic field measurement technologies for chips and fill the technological gap in the synchronous and rapid detection of three-dimensional near-field magnetic fields for chips, this invention leverages the unique technical advantages of diamond NV centers: high magnetic field detection sensitivity, excellent spatial resolution, and the absence of electromagnetic interference and electromagnetic coupling effects. It employs a blocky cubic diamond NV center structure, combined with a confocal optical path design, to precisely focus the excitation laser onto the three-dimensional spatial region of the diamond NV center system. This breaks through the limitations of traditional two-dimensional measurement dimensions, enabling synchronous, rapid, and high-precision measurement of the three-dimensional near-field magnetic field across the entire chip surface. This provides a comprehensive, multi-dimensional, and complete characterization of the chip's near-field magnetic field, fully restoring the chip's three-dimensional electromagnetic distribution characteristics, accurately evaluating the chip's overall electromagnetic compatibility performance, and providing core technical support for chip electromagnetic interference analysis, structural optimization, and reliability improvement.

[0029] Specifically, this embodiment discloses a rapid confocal measurement device for the near-field magnetic field of a chip surface based on diamond NV color centers, such as... Figure 5 As shown, it includes: an excitation optical path assembly, a microwave control assembly, a fluorescence acquisition and detection assembly, a diamond NV color center sensing unit, a three-dimensional displacement driving assembly, and a main control unit; The laser emission optical path of the excitation optical path assembly is aligned with the diamond NV color center sensing unit to generate and output modulated excitation laser; The microwave control component is electrically connected to the diamond NV color center sensing unit to provide the control microwave signal; The fluorescence acquisition and detection component is arranged on the fluorescence output side of the excitation optical path component to receive the fluorescence signal emitted by the stimulated emission of the diamond NV color center sensing unit. The diamond NV color center sensing unit is fixedly mounted on the three-dimensional displacement drive assembly and driven by the three-dimensional displacement drive assembly to perform a three-dimensional spatial scan relative to the chip under test. The main control unit is electrically connected to the excitation optical path assembly, microwave control assembly, fluorescence acquisition and detection assembly, and three-dimensional displacement drive assembly, respectively, and is used to perform full device timing coordination control, detection signal acquisition, and data processing.

[0030] Furthermore, the excitation optical path assembly is arranged sequentially along the laser propagation direction as follows: laser 1, first polarizer 11, PBS energy beam splitter 2, front plano-concave mirror 4, acousto-optic modulator 3, rear plano-concave mirror 6, second polarizer 12, first aperture stop 7, reflector 5, light passage, dichroic mirror 8, and first plan achromatic objective lens 10; the reflected reference calibration beam branch split from the PBS energy beam splitter 2 is provided with a second aperture stop 24. The laser 1 is a high-power laser with a wavelength of 532nm, and the output laser is used to excite the NV color center inside the diamond; the acousto-optic modulator 3 is used to convert the continuous laser into a modulated laser; the front plano-concave mirror 4 is used to expand the laser beam, which is convenient for the acousto-optic modulator 3 to modulate; the first aperture stop 7 is used to filter the modulated laser beam; the second aperture stop 24 is used to constrain the light transmission range of the reference calibration beam, filter stray light, and complete the optical path energy reference calibration; the dichroic mirror 8 is used to reflect the green laser and transmit the red fluorescence, which is convenient for the APD to collect the red fluorescence; the first polarizer 11 and the second polarizer 12 are used to change the laser from circular polarization to linear polarization, and the change of polarization is used to modulate the laser; the first plan achromatic objective lens 10 is composed of multiple lenses (including lenses with focusing function), and is used as a focusing lens in this embodiment.

[0031] Specifically, the laser output from laser 1 first passes through the first polarizer 11 for polarization screening before entering the PBS energy beam splitter 2. The PBS energy beam splitter 2 splits the incident laser into a transmitted beam and a reflected beam according to a 50:50 energy ratio. The transmitted beam, as the main measurement beam, enters the front plano-concave mirror 4, while the reflected beam, as the reference calibration beam, passes through the second aperture stop 24 and is then led out to calibrate the optical path reference. The transmitted beam is expanded and collimated by the front plano-concave mirror 4 and then enters the acousto-optic modulator 3 to complete laser modulation. The modulated beam is then collimated and shaped a second time by the rear plano-concave mirror 6. The shaped beam passes through the second polarizer 12 and the first aperture stop 7 in sequence to complete beam aperture limitation and secondary polarization screening, resulting in a collimated polarized beam. The collimated polarized beam is deflected by the reflector 5 and then passes through the light-transmitting aperture before entering the dichroic mirror 8. The transmitted beam from the dichroic mirror 8 is focused by the first flat achromatic objective lens 10 and enters the interior of the diamond NV color center sensing unit.

[0032] Furthermore, the microwave control components include: a microwave generator 16, a power amplifier 17, a microwave switch 22, and a microwave antenna 27; wherein: the microwave generator 16 is used to provide microwave signals to the microwave antenna 27 for microwave modulation of the NV color center; and the power amplifier 17 is used to amplify the microwave signals.

[0033] Specifically, the microwave signal output by the microwave generator 16 is selected by the microwave switch 22 and then sent to the power amplifier 17 for power amplification. The amplified microwave signal is coupled to the diamond NV color center sensing unit via the microwave antenna 27 to realize the internal NV color center quantum state control.

[0034] Furthermore, the fluorescence acquisition and detection assembly includes: a filter 9, a second flat achromatic objective lens 26, an APD avalanche photodetector 13, and a lock-in amplifier 15; wherein: the filter 9 is used to filter out green laser light and ambient light noise; the dichroic mirror 8, the filter 9, and the focusing lens are connected by a cage rod 29 to ensure laser collimation; the APD avalanche photodetector 13 is used to collect red fluorescence and convert the optical signal into an electrical signal; the lock-in amplifier 15 is used to acquire and amplify the signal detected by the APD, filter out high-frequency noise, and improve the signal-to-noise ratio.

[0035] Specifically, the fluorescence emitted by the stimulated emission of the diamond NV color center sensing unit passes sequentially through the first flat achromatic objective 10 and the filter 9 to filter out stray light before being incident on the dichroic mirror 8. The fluorescence is reflected by the dichroic mirror 8 and then passes through the second flat achromatic objective 26 before being incident on the APD avalanche photodetector 13. The APD avalanche photodetector 13 converts the optical signal into an electrical signal and transmits it to the lock-in amplifier 15 to complete the signal noise reduction and amplification processing.

[0036] Furthermore, the diamond NV color center sensing unit includes: a bulk diamond NV color center cube 14 and a permanent magnet 28; Permanent magnet 28 is mounted on the side of the bulk diamond NV color center cube 14 to apply a static bias magnetic field to the internal NV color center; The bulk diamond NV color center cube 14 serves as the core of the optical-magnetic coupling detection, and is respectively connected to the light-emitting end of the excitation optical path component and the microwave antenna 27 of the microwave control component.

[0037] Furthermore, the three-dimensional displacement driving component includes: an electrically controlled three-dimensional displacement stage 20 and an electrically controlled displacement stage control box 21; wherein: the electrically controlled three-dimensional displacement stage 20 is used to move the diamond NV color center to perform confocal three-dimensional spatial near-field magnetic field scanning.

[0038] Specifically, the diamond NV color center sensing unit is fixed on the electrically controlled three-dimensional displacement stage 20. The electrically controlled displacement stage control box 21 receives instructions from the main control unit and drives the electrically controlled three-dimensional displacement stage 20 to perform three-dimensional movement along the X / Y / Z axes, so that the diamond NV color center sensing unit can perform confocal three-dimensional near-field magnetic field scanning.

[0039] Furthermore, the main control unit includes: a multi-channel arbitrary waveform generator 18 and a computer 19; wherein: the multi-channel arbitrary waveform generator 18 is used for timing control of the laser 1, microwave generator 16, microwave switch 22, and electrically controlled three-dimensional displacement stage 20.

[0040] Specifically, computer 19 sends control commands to multi-channel arbitrary waveform generator 18. The multi-channel arbitrary waveform generator outputs multiple synchronous timing signals to perform synchronous timing control on the excitation optical path component, microwave control component, fluorescence acquisition and detection component, and three-dimensional displacement drive component, respectively. The electrical signals acquired by the fluorescence acquisition and detection component are transmitted back to computer 19 to complete data processing.

[0041] Furthermore, an electromagnetic shielding cover 23 is also provided. The dichroic mirror 8, the filter 9, the first flat achromatic objective lens 10, the second flat achromatic objective lens 26, and the APD avalanche photodetector 13 are all arranged inside the electromagnetic shielding cover 23 to prevent the APD avalanche photodetector 13 from being interfered with by electromagnetic radiation generated by the microwave antenna 27.

[0042] In addition, the various electronic components in the device are connected by communication cables 25.

[0043] Next, we will further introduce the rapid confocal measurement method for the three-dimensional near-field magnetic field on the chip surface that can be achieved by the device described in this embodiment, including the following steps: 1. Powering on and testing the equipment Turn on the power to supply power to the computer 19, laser 1, microwave generator 16, multi-channel arbitrary waveform generator 18, and microwave switch 22. Start the measurement and control software and lock-in amplifier data acquisition and processing software on the computer 19. Use the measurement and control software to check whether the laser control, microwave generator control, and microwave switch status are normal, and check whether the output and input of the multi-channel arbitrary waveform generator 18 are normal. Use the lock-in amplifier data acquisition and processing software to check whether the APD avalanche photodetector 13 is working properly.

[0044] 2. Alignment of the diamond NV color mandrel axis

[0045] Turn on the laser 1, the multi-channel arbitrary waveform generator 18, and the computer control software. Use the software to control the laser 1 to output a continuous laser. The laser shines on the bulk diamond NV color center cube 14 through the lens group and the reflector group. Adjust the clamp angle of the bulk diamond NV color center cube 14. Observe the APD fluorescence signal collected by the data acquisition software built into the lock-in amplifier 15 on the computer 19. When the collected APD fluorescence signal is the strongest, fix the clamp.

[0046] 3. Laser modulation

[0047] like Figure 1As shown, the laser light passing through the PBS energy beam splitter 2 enters the acousto-optic modulator 3. A clock signal is generated by the multi-channel arbitrary waveform generator 18, and the computer 19 controls the acousto-optic modulator 3 according to the clock signal, converting the continuous laser light into a modulated laser light. This device performs secondary modulation on the laser light. The laser light after the first modulation is irradiated through the reflector 5 and then enters the acousto-optic modulator 3 for secondary modulation, which better suppresses noise and improves the signal-to-noise ratio and measurement sensitivity of ODMR (optical detection magnetic resonance).

[0048] 4. Quantum state microwave modulation

[0049] The modulated laser light, after passing through a dichroic mirror 8, illuminates the bulk diamond NV center cube 14, exciting the internal color centers and causing them to emit red fluorescence. Using a computer 19, according to the clock signal provided by a multi-channel arbitrary waveform generator 18, the microwave switch 22 is controlled to emit the required microwave signal, which is then amplified by a power amplifier 17 and sent to a microwave antenna 27 to perform quantum state manipulation of the NV centers.

[0050] 5. Decoupled sequence control laser 1, microwave switch 22, and APD avalanche photodetector 13

[0051] After laser excitation and microwave modulation are completed, a computer 19 controls a multi-channel arbitrary waveform generator 18 to achieve synchronous control of laser excitation, microwave switching 22, microwave frequency sweeping, and APD acquisition. The working time and sequence are determined by the dynamic decoupling sequence used during measurement. Figure 2 Examples of decoupling sequences include: a) a laser excitation control sequence, which generates a square wave signal as shown in the figure on the multi-channel arbitrary waveform generator 18, and the computer 19 converts the square wave signal into a control signal to control the acousto-optic modulator 3 to emit laser at a high level; b) a microwave signal control sequence, in which the microwave switch 22 emits a microwave signal when the signal is high; c) a control sequence for controlling the frequency sweep signal, in which the frequency of the microwave changes once when the square wave signal controlling the frequency sweep changes from low level to high level; and d) a control sequence for APD data acquisition, in which the lock-in amplifier 15 connected to the APD avalanche photodetector 13 starts transmitting data on the fluorescence signal intensity when the signal is high.

[0052] 6. Rapid 3D Field Scanning of Chip Surface

[0053] After completing the above operations, the device has completed the confocal magnetic field measurement of a single point on the chip surface. Next, the three-dimensional space of the chip surface will be scanned. The confocal laser excitation device designed in the system can focus the laser to a single point, exciting the NV centers at different locations inside the bulk diamond NV center cube 14, thereby achieving layer-by-layer measurement of the three-dimensional magnetic field on the chip surface. This confocal laser excitation device is as follows... Figure 3 As shown.

[0054] By changing the position of the laser focusing inside the bulk diamond NV color center cube 14 using an electrically controlled three-dimensional displacement stage 20, and repeating steps 3-5, the three-dimensional near-field magnetic field intensity measurement of the chip surface can be realized. Figure 4 This visually demonstrates the process of an electrically controlled displacement stage driving a blocky diamond NV color center cube 14 to move, and using a confocal laser to perform three-dimensional spatial scanning. Figure 4 By scanning the displacement direction layer by layer and point by point as shown, the three-dimensional spatial global characterization and distribution measurement of the near-field magnetic field of the chip can be realized.

[0055] 7. Data Processing

[0056] After collecting fluorescence data containing near-field magnetic field information of the chip under test using the APD avalanche photodetector 13 and lock-in amplification, the fluorescence data needs to be processed. First, the fluorescence data obtained by frequency sweeping at each point is fitted to obtain ODMR spectra, and the half-width and height information is extracted to achieve rapid measurement of magnetic field strength. At this point, the relative value of the magnetic field strength is obtained. Next, the data is compared with the preset standard points to obtain the absolute value of the near-field magnetic field at each point.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0058] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rapid measurement device for near-field magnetic field confocalization on a chip surface based on diamond NV color centers, characterized in that, include: Excitation optical path assembly, microwave control assembly, fluorescence acquisition and detection assembly, diamond NV color center sensing unit, three-dimensional displacement driving assembly, and main control unit; The laser emission optical path of the excitation optical path assembly is aligned with the diamond NV color center sensing unit to generate and output modulated excitation laser; The microwave control component is electrically connected to the diamond NV color center sensing unit to provide the control microwave signal; The fluorescence acquisition and detection component is arranged on the fluorescence output side of the excitation optical path component to receive the fluorescence signal emitted by the stimulated emission of the diamond NV color center sensing unit. The diamond NV color center sensing unit is fixedly mounted on the three-dimensional displacement drive assembly and driven by the three-dimensional displacement drive assembly to perform a three-dimensional spatial scan relative to the chip under test. The main control unit is electrically connected to the excitation optical path assembly, microwave control assembly, fluorescence acquisition and detection assembly, and three-dimensional displacement drive assembly, respectively, and is used to perform full device timing coordination control, detection signal acquisition, and data processing.

2. The rapid measurement device for near-field magnetic field confocalization of chip surface based on diamond NV color centers according to claim 1, characterized in that, The excitation optical path assembly is arranged sequentially along the laser propagation direction as follows: laser, first polarizer, PBS energy beam splitter, front plano-concave mirror, acousto-optic modulator, rear plano-concave mirror, second polarizer, first aperture stop, mirror, aperture, dichroic mirror, and first plan achromatic objective lens; the second aperture stop is set in the reflected reference calibration beam branch split by the PBS energy beam splitter. The laser output from the laser first passes through a first polarizer for polarization screening before entering a PBS energy beam splitter. The PBS energy beam splitter splits the incident laser into a transmitted beam and a reflected beam with a 50:50 energy ratio. The transmitted beam, as the main measurement beam, enters a front plano-concave mirror, while the reflected beam, as a reference calibration beam, passes through a second aperture stop and is then led out to calibrate the optical path reference. The transmitted beam is expanded and collimated by the front plano-concave mirror before entering an acousto-optic modulator to complete laser modulation. The modulated beam is then collimated and shaped a second time by a rear plano-concave mirror. The shaped beam passes through a second polarizer and a first aperture stop in sequence to complete beam aperture limitation and secondary polarization screening, resulting in a collimated polarized beam. The collimated polarized beam is deflected by a reflector and then passes through a light-transmitting aperture before entering a dichroic mirror. The transmitted beam from the dichroic mirror is focused by a first flat-field achromatic objective and enters the interior of the diamond NV color center sensing unit.

3. The rapid measurement device for near-field magnetic field confocalization on a chip surface based on diamond NV color centers according to claim 1, characterized in that, The microwave control components include: a microwave generator, a power amplifier, a microwave switch, and a microwave antenna; The microwave signal output by the microwave generator is selected by a microwave switch and then sent to a power amplifier for power amplification. The amplified microwave signal is coupled to the diamond NV color center sensing unit via a microwave antenna to achieve internal NV color center quantum state control.

4. The rapid measurement device for near-field magnetic field confocalization of chip surface based on diamond NV color centers according to claim 2, characterized in that, The fluorescence acquisition and detection components include: a filter, a second-plan achromatic objective lens, an APD avalanche photodetector, and a lock-in amplifier; The fluorescence emitted by the stimulated emission of the diamond NV color center sensing unit passes sequentially through the first flat achromatic objective lens and a filter to remove stray light before being incident on a dichroic mirror. The fluorescence is reflected by the dichroic mirror and then passes through the second flat achromatic objective lens before being incident on the APD avalanche photodetector. The APD avalanche photodetector converts the optical signal into an electrical signal and transmits it to a lock-in amplifier to complete the signal noise reduction and amplification process.

5. The rapid measurement device for near-field magnetic field confocalization on the surface of a chip based on diamond NV color centers according to claim 1, characterized in that, The diamond NV color center sensing unit includes: a bulk diamond NV color center cube and a permanent magnet; Permanent magnets are mounted on the sides of a bulk diamond NV color center cube to apply a static bias magnetic field to the internal NV color center. The bulk diamond NV color center cube serves as the core of the optical-magnetic coupling detection, connecting to the light-emitting end of the excitation optical path component and the microwave antenna of the microwave control component, respectively.

6. The rapid measurement device for near-field magnetic field confocalization of chip surface based on diamond NV color centers according to claim 1, characterized in that, The three-dimensional displacement drive assembly includes: an electrically controlled three-dimensional displacement stage and an electrically controlled displacement stage control box; The diamond NV color center sensing unit is fixed to the electronically controlled three-dimensional displacement stage. The electronically controlled displacement stage control box receives instructions from the main control unit and drives the electronically controlled three-dimensional displacement stage to perform three-dimensional movement along the X / Y / Z axes, so that the diamond NV color center sensing unit can perform confocal three-dimensional near-field magnetic field scanning.

7. The rapid measurement device for near-field magnetic field confocalization of chip surface based on diamond NV color centers according to claim 1, characterized in that, The main control unit includes a multi-channel arbitrary waveform generator and a computer. The computer sends control commands to the multi-channel arbitrary waveform generator, which outputs multiple synchronous timing signals to synchronously control the excitation optical path component, microwave control component, fluorescence acquisition and detection component, and three-dimensional displacement drive component. The electrical signals acquired by the fluorescence acquisition and detection component are transmitted back to the computer for data processing.

8. The rapid measurement device for near-field magnetic field confocalization of chip surface based on diamond NV color centers according to claim 4, characterized in that, It is also equipped with an electromagnetic shield, and the dichroic mirror, filter, first flat achromatic objective lens, second flat achromatic objective lens, and APD avalanche photodetector are all arranged inside the electromagnetic shield.

Images