Semiconductor device and manufacturing method therefor

Abstract

Provided in the present invention are a semiconductor device and a manufacturing method therefor. In the semiconductor device, a first substrate comprises a first through hole through a first surface and a second surface, and a second substrate comprises a second through hole through a third surface and a fourth surface; a microwave transmission line is on the third surface, a microwave antenna on a bottom surface of a diamond with an NV color center is erected over the second through hole, and the microwave antenna is coupled to the microwave transmission line; and a laser source element is below the fourth surface, and a photodetector is on the first surface. In the present invention, a semiconductor device in which a laser source and a diamond chip are integrated is designed, and an integrated magnetic field sensor is implemented by using MEMS technology, wherein same can be produced in batches at a low cost. Moreover, the laser source is aligned to the through hole of the microwave antenna, thereby improving the use flexibility and reliability of the magnetic field sensor. In addition, a side wall of the first through hole is inclined, thereby improving the fluorescence collection efficiency of the photodetector and the sensitivity of the magnetic field sensor. Finally, a long-pass filter and a reflective metal layer further improve the sensitivity of a quantum magnetic field sensor of the same size.

Description

A semiconductor device and its fabrication method Technical Field

[0001] This invention belongs to the field of semiconductor integrated circuit manufacturing technology, and in particular relates to a semiconductor device and its preparation method. Background Technology

[0002] Magnetism, as a fundamental physical property of matter, is closely related to people's lives. Magnetic fields can be applied in physics, geology, magnetic resonance imaging, power transmission, and other fields, providing important support for medical diagnosis, energy development, and transportation. Therefore, the precise measurement of magnetic fields is extremely important. Compared with traditional fiber optic, magnetoresistive, and Hall effect magnetometers, quantum effect-based magnetometers are widely studied due to their higher sensitivity, which can meet the needs of more accurate magnetic field measurements.

[0003] The superconducting quantum interference device based on the Josephson effect and flux quantization is one of the most sensitive vector magnetometers known to date, achieving a sensitivity of 0.3 fT·Hz. -1 / 2 A light-pumped magnetometer utilizing alkali metal atomic vapor can achieve a flux density of 10 fT·Hz. -1 / 2 Furthermore, it exhibits no zero-point drift and a fast response speed; the sensitivity of the spin-exchange relaxation magnetometer is unaffected by spin exchange relaxation and can reach 0.16 fT·Hz. -1 / 2 However, while the above technologies have high sensitivity, they are also constrained by many factors: superconducting quantum interference devices need to operate in a low-temperature environment, and low-temperature systems are bulky and expensive; optically pumped magnetometers are scalar magnetometers, and the atomic vapor chamber needs to operate at 100°C, requiring additional heating devices; spinless exchange relaxation magnetometers have a contradiction between dynamic range and sensitivity, cannot be compatible with magnetic fields of the μT level and above, and require magnetic shielding devices.

[0004] Diamond NV color centers, as a solid-state quantum magnetic sensing platform, can detect 10... -13 Measuring magnetic fields in the range of -10T, while also possessing advantages such as high sensitivity and room temperature detection, has become a research hotspot in recent years. Initially, diamond magnetic sensors based on optical platforms and benchtop equipment could achieve 195 fT·Hz. -1 / 2 However, it sacrifices spatial resolution and has a large overall size, making it unsuitable for field measurements in outdoor environments. The subsequent improved diamond magnetic sensor based on fiber excitation is smaller in size, but it still requires an external laser to provide laser pumping and an imaging device to align the laser and microwave antenna, which is also not conducive to portable testing.

[0005] Therefore, there is an urgent need for a structure or method for magnetic field sensors that can achieve miniaturization and low-cost mass production while meeting high sensitivity requirements.

[0006] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating the understanding of those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because these solutions have been described in the background section of this application. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a semiconductor device and its fabrication method to solve the problems of large size and high manufacturing cost of magnetic field sensors in the prior art.

[0008] To achieve the above objectives, the present invention provides a semiconductor device comprising: a laser source element and a diamond chip;

[0009] The diamond chip includes a photodetector, a support structure, a diamond with NV color centers, and a microwave excitation structure.

[0010] The support structure includes a first substrate and a second substrate. The first substrate includes opposing first surfaces, a second surface, and a first through-hole penetrating the first surface and the second surface. The second substrate includes opposing third surfaces, a fourth surface, and a second through-hole penetrating the third surface and the fourth surface. The projected area of ​​the first through-hole on the second surface is greater than or equal to the projected area of ​​the diamond with NV color centers on the second surface, and the projected area of ​​the second through-hole on the second surface is less than the projected area of ​​the diamond with NV color centers on the second surface.

[0011] The microwave excitation structure includes a microwave antenna and a microwave transmission line. The microwave transmission line is located on the third surface of the second substrate where the second through hole is not provided. The microwave antenna is located on the diamond bottom surface with NV color centers. The diamond bottom surface with NV color centers is mounted on the second through hole on the third surface through the first through hole. The microwave antenna and the microwave transmission line are coupled together.

[0012] The laser source element is located below the fourth surface of the second substrate and is used to generate a laser that penetrates the second via from the fourth surface to reach the diamond with NV color centers; the photodetector is located on the first surface of the first substrate and is used to receive the target fluorescence signal generated by the microwave excitation of the diamond with NV color centers by the microwave antenna and convert the target fluorescence signal into a photocurrent signal.

[0013] Optionally, the laser wavelength generated by the laser source element is 450 nm to 570 nm.

[0014] Optionally, the diamond chip further includes a long-pass filter located between the first surfaces of the first substrate of the photodetector housing. The long-pass filter is used to filter out interference light that interferes with the photodetector's reception of the target fluorescence signal generated by the microwave excitation of the diamond with NV color centers.

[0015] Optionally, a reflective metal layer is provided on the sidewall of the first substrate, and the reflective metal layer has a reflectivity of greater than or equal to 90% for the target fluorescence signal.

[0016] Optionally, the sidewall of the first through hole forms a preset inclination angle with the first surface, and the diameter of the first through hole on the first surface is larger than the diameter of the first through hole on the second surface.

[0017] Optionally, the laser generated by the laser source element coincides with the projection of the center point of the second through hole and the center point of the microwave antenna on the diamond base with NV color centers onto the second surface.

[0018] Optionally, the semiconductor device further includes a package and package leads. The package is used to hermetically seal the laser source element and the diamond chip. One end of the package lead is located inside the package and forms corresponding electrical connections with the laser source element and the diamond chip through bonding leads. The other end of the package lead is located outside the package and leads out the corresponding electrical connections between the laser source element and the diamond chip.

[0019] The present invention also provides a method for fabricating a semiconductor device, the method being used to fabricate any of the semiconductor devices described above, the method comprising:

[0020] Provides a support structure with microwave transmission lines and a diamond with NV color centers equipped with a microwave antenna;

[0021] The bottom surface of the diamond with the NV color center, which is equipped with a microwave antenna, is disposed on the third surface of the support structure through the first through hole of the support structure, so that the microwave antenna and the microwave transmission line are coupled together, and the projection of the center point of the microwave antenna and the center point of the second through hole on the second surface coincides.

[0022] The long-pass filter and the photodetector are sequentially mounted on the first through hole of the first surface to obtain a diamond chip.

[0023] The laser source element and the diamond chip are fixed on the housing base, and the diamond chip is fixed on the laser source element, so that the laser generated by the laser source element coincides with the projection of the center of the microwave antenna on the second surface of the support structure; bonding wires are provided to electrically connect the diamond chip and the laser source element to the housing pins of the housing base; a housing cover plate is provided and hermetically sealed with the housing base to form a packaged housing, so that the laser source element and the diamond chip are hermetically sealed inside the packaged housing.

[0024] Optionally, the method for fabricating the support structure for the microwave transmission line includes:

[0025] A first substrate is provided, the first substrate including opposing first and second surfaces;

[0026] A first barrier layer is disposed on a first surface of the first substrate, and a second barrier layer is disposed on a second surface of the first substrate;

[0027] Etch the first barrier layer, the first substrate, and the second barrier layer to obtain a first through-hole penetrating the first barrier layer, the first substrate, and the second barrier layer;

[0028] A reflective metal layer is applied to the sidewall surface of the first through hole;

[0029] A second substrate is provided, the second substrate including opposing third and fourth surfaces;

[0030] A third barrier layer is disposed on the third surface of the second substrate;

[0031] A patterned microwave transmission line is provided on the third barrier layer;

[0032] The microwave transmission line, the third barrier layer, and the second substrate are etched to obtain a second through-hole penetrating the microwave transmission line, the third barrier layer, and the second substrate;

[0033] The second surface of the first substrate is bonded to the third surface of the second substrate, so that the central axis of the first through hole and the second through hole coincide, thus obtaining a support structure with microwave transmission lines.

[0034] Optionally, the method for obtaining the first via is as follows: dry etching the first barrier layer to obtain a patterned first barrier layer on the first surface of the first substrate; depositing a patterned mask layer on the patterned first barrier layer and the exposed first surface; performing wet etching on the first substrate using the mask layer as a mask, and obtaining a first via with a preset tilt angle between the sidewall and the first surface through anisotropic wet etching.

[0035] As described above, the semiconductor device and its fabrication method of the present invention have the following beneficial effects:

[0036] This invention designs a semiconductor device that integrates a laser source and a diamond chip, enabling the creation of a miniaturized and portable magnetic field sensor using standard MEMS technology. This sensor can be mass-produced, reducing production costs, and achieving high sensitivity while maintaining a small size, which is beneficial for applications in wearable, handheld, and other products.

[0037] This invention achieves high-precision, small-volume alignment of the microwave antenna and the laser source by setting a laser source and a diamond chip microwave antenna in a semiconductor device through a through-hole structure that can be directly aligned using standard semiconductor processes. This improves the flexibility and reliability of the magnetic field sensor.

[0038] This invention, through the design of the inclined sidewall of the first through hole, enables the photodetector to collect the target fluorescence signal generated by the excitation of the side of the diamond, thereby improving the fluorescence collection efficiency of the photodetector and thus improving the sensitivity of the magnetic field sensor.

[0039] This invention reduces the loss of the target fluorescence signal generated by microwave excitation of diamonds with NV color centers and the interference signal on the target fluorescence signal by setting a long-pass filter and a reflective metal layer, thereby further improving the sensitivity of the quantum magnetic field sensor of the same volume. Attached Figure Description

[0040] Figure 1 shows a schematic side cross-sectional view of the semiconductor device structure in this invention.

[0041] Figure 2 shows a top sectional view of the semiconductor device structure in this invention.

[0042] Figure 3 shows the spectrum of magnetic detection sensitivity of the semiconductor device structure in this invention at different spectral frequencies.

[0043] Figure 4 shows a schematic diagram of the structure presented by setting the first substrate in an example of step 1 of the semiconductor device structure fabrication method of the present invention.

[0044] Figure 5 shows a schematic diagram of the structure presented by etching the first barrier layer in step 1 of the semiconductor device structure fabrication method of the present invention.

[0045] Figure 6 shows a schematic diagram of the structure presented by setting the first through hole in step 1 of the semiconductor device structure fabrication method of the present invention.

[0046] Figure 7 shows a schematic diagram of the structure presented in step 1 of the semiconductor device structure fabrication method of the present invention, where a reflective metal layer is set.

[0047] Figure 8 shows a schematic diagram of the structure presented in step 1 of the semiconductor device structure fabrication method of the present invention, where a third barrier layer is set.

[0048] Figure 9 shows a schematic diagram of the structure presented in step 1 of the semiconductor device structure fabrication method of the present invention, where a microwave transmission line is set up.

[0049] Figure 10 shows a schematic diagram of the structure presented by etching the third barrier layer in an example of step 1 of the semiconductor device structure fabrication method of the present invention.

[0050] Figure 11 shows a schematic diagram of the structure presented in step 1 of the semiconductor device structure fabrication method of the present invention, where a second through hole is set.

[0051] Figure 12 shows a schematic diagram of the structure presented by bonding the first substrate and the second substrate in an example of step 1 of the semiconductor device structure fabrication method of the present invention.

[0052] Figure 13 shows a schematic diagram of the structure presented by setting a microwave metal film in step 1 of the semiconductor device structure fabrication method of the present invention.

[0053] Figure 14 shows a schematic diagram of the structure of the microwave antenna obtained in step 1 of the semiconductor device structure fabrication method of the present invention.

[0054] Figure 15 shows a schematic top view of the graphical distribution of the microwave antenna obtained in step 1 of the semiconductor device structure fabrication method of the present invention.

[0055] Figure 16 shows a schematic diagram of the diamond-supported structure in step 2 of the semiconductor device structure fabrication method of the present invention.

[0056] Figure 17 shows a schematic diagram of the long-pass filter structure in step 3 of the semiconductor device structure fabrication method of the present invention.

[0057] Figure 18 shows a schematic diagram of the photodetector structure in step 3 of the semiconductor device structure fabrication method of the present invention.

[0058] Figure 19 shows a schematic diagram of the structure of setting the laser source element and diamond chip to the tube base in step 4 of the semiconductor device structure fabrication method of the present invention.

[0059] Figure 20 shows a schematic diagram of the structure of setting bonding leads in step 4 of the semiconductor device structure fabrication method of the present invention.

[0060] Figure 21 shows a schematic diagram of the structure of the casing cover plate in step 4 of the semiconductor device structure fabrication method of the present invention.

[0061] Figure 22 shows a schematic diagram of the structure connecting the printed circuit board in step 4 of the semiconductor device structure fabrication method of the present invention.

[0062] The reference numerals in the attached diagrams are explained as follows: 10. Laser source element; 11. Laser diode heat sink; 20. Photodetector; 21. Long-pass filter; 30. Support structure; 31. First substrate; 32. First through-hole; 33. Second substrate; 34. Second through-hole; 35. Microwave transmission line; 36. Reflective metal layer; θ. Preset tilt angle; 40. Diamond chip; 41. Microwave antenna; 42. Diamond; 50. Package casing; 51. Casing base; 52. Casing cover; 53. Casing pins; 54. Heat sink; 55. Laser diode electrode; 56. Photodetector electrode; 57. Printed circuit board; 58. Bonding wire; 61. First barrier layer; 62. Second barrier layer; 63. Third barrier layer; 64. Microwave metal film; 65. Microwave metal layer. Detailed Implementation

[0063] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0064] In the detailed description of embodiments of the present invention, for ease of explanation, the schematic diagrams illustrating the device structure may be partially enlarged without adhering to the general scale, and the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. Furthermore, in actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0065] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the accompanying drawings for devices in use or operation.

[0066] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0067] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0068] In existing technologies, magnetometers based on quantum effects have higher sensitivity compared to traditional fiber optic, magnetoresistive, and Hall effect magnetometers, and are widely studied because they can meet the requirements for more precise magnetic field measurements. The superconducting quantum interference device based on the Josephson effect and flux quantization is one of the most sensitive vector magnetometers known to date, achieving a sensitivity of 0.3 fT·Hz. -1 / 2 However, superconducting quantum interference devices require cryogenic environments to operate, and cryogenic systems are bulky and expensive; optically pumped magnetometers using alkali metal atomic vapor can achieve 10 fT·Hz. -1 / 2 Furthermore, it exhibits no zero-point drift and a fast response speed; however, the optically pumped magnetometer is a scalar magnetometer, and the atomic vapor chamber requires operation at 100°C, necessitating an additional heating device. The spin-free exchange relaxation magnetometer, on the other hand, is unaffected by spin exchange relaxation and can achieve a sensitivity of 0.16 fT·Hz. -1 / 2 However, spin-free exchange relaxation magnetometers have a contradiction between dynamic range and sensitivity, cannot be compatible with magnetic fields of the μT level and above, and require magnetic shielding devices.

[0069] Diamond 42NV (Nitrogen-Vacancy) color centers, as a solid-state quantum magnetic sensing platform, can detect 10... -13 Measuring magnetic fields in the range of -10T, while also possessing advantages such as high sensitivity and room temperature detection, has become a research hotspot in recent years. The Diamond 42 magnetic sensor, initially based on an optical platform and benchtop equipment, could achieve 195 fT·Hz. -1 / 2 However, this approach sacrifices spatial resolution and results in a large overall size, making it unsuitable for field measurements in outdoor environments. The subsequent improved diamond 42 magnetic sensor based on fiber excitation, while smaller in size, still requires an external laser for pumping. Furthermore, the use of an external laser fiber optic cable necessitates alignment between the laser and the microwave antenna 41 using an imaging device, which is also unsuitable for portable testing. Moreover, existing diamond 42 magnetic sensors involve processing and assembling the individual components separately, making it difficult to fabricate using standard semiconductor processes. This results in high manufacturing costs and hinders further reduction in size.

[0070] The present invention provides a semiconductor device, as shown in Figures 1 and 2, wherein Figure 1 is a side sectional view of the semiconductor device and Figure 2 is a top sectional view of the semiconductor device. The semiconductor device includes a laser source element 10 and a diamond chip 40.

[0071] The diamond chip 40 includes a photodetector 20, a support structure 30, a diamond 42 with NV color centers, and a microwave excitation structure.

[0072] The support structure 30 includes a first substrate 31 and a second substrate 33. The first substrate 31 includes a first surface, a second surface, and a first through-hole 32 penetrating the first surface and the second surface. The second substrate 33 includes a third surface, a fourth surface, and a second through-hole 34 penetrating the third surface and the fourth surface. The projected area of ​​the first through-hole 32 on the second surface is greater than or equal to the projected area of ​​the diamond 42 with NV color centers on the second surface, and the projected area of ​​the second through-hole 34 on the second surface is less than the projected area of ​​the diamond 42 with NV color centers on the second surface.

[0073] The microwave excitation structure includes a microwave antenna 41 and a microwave transmission line 35. The microwave transmission line 35 is located on the third surface of the second substrate 33 where the second through hole 34 is not provided. The microwave antenna 41 is located on the bottom surface of the diamond 42 with NV color centers. The bottom surface of the diamond 42 with NV color centers is mounted on the second through hole 34 on the third surface through the first through hole 32. The microwave antenna 41 and the microwave transmission line 35 are coupled together.

[0074] The laser source element 10 is located below the fourth surface of the second substrate 33 and is used to generate laser light that penetrates the second through hole 34 from the fourth surface to reach the diamond 42 with NV color centers; the photodetector 20 is located on the first surface of the first substrate 31 and is used to receive the target fluorescence signal generated by the microwave excitation of the diamond 42 with NV color centers by the microwave antenna 41 and convert the target fluorescence signal into a photocurrent signal.

[0075] This invention, through the setting of the first through-hole 32 in the first substrate 31 and the second through-hole 34 in the second substrate 33 and their aperture sizes, allows the diamond 42 to be placed at the bottom of the first through-hole 32 and supported above the second through-hole 34. The first through-hole 32 on the second surface secures and protects the diamond 42, enabling the use of MEMS technology to achieve small-volume integrated assembly of the diamond 42 magnetic field sensor while ensuring the positional stability of the diamond 42 within it. Simultaneously, by designing a semiconductor device integrating the laser source and the diamond chip 40, a magnetic field sensor is obtained within the laser source. Standard MEMS technology can be used to achieve miniaturization and portability of the magnetic field sensor, allowing for mass production, reducing production costs, and achieving high sensitivity that meets the requirements of portable applications while maintaining a small size. This is beneficial for upgrades in wearable, handheld, and other products. Furthermore, the design of placing the laser source and the microwave antenna 41 of the diamond chip 40 within the semiconductor device allows for direct alignment during the fabrication of the second through-hole 34 and the microwave antenna 41 using standard semiconductor processes. This achieves high-precision, compact alignment of the microwave antenna 41 and the laser source without the need for additional imaging equipment for aligning the microwave antenna 41 and the laser source element 10. This significantly reduces the size and weight of the equipment required for the normal operation of the magnetic field sensor, improving its flexibility and reliability. Finally, by placing the microwave antenna 41 on the bottom surface of the diamond 42, the microwave field can be excited directly, reducing the exponential decay of the microwave field intensity as the distance from the diamond 42 increases. This effectively reduces microwave power loss and lowers the overall power consumption of the magnetic field sensor.

[0076] In one embodiment, the laser wavelength generated by the laser source element 10 is 450 nm to 570 nm.

[0077] This invention, by setting the laser wavelength range, can ensure precise control of the electron spin direction within the 42NV color center of diamond, thereby achieving high sensitivity to changes in the magnetic field.

[0078] In one embodiment, the laser source element 10 is a laser diode, which generates a pump laser power of approximately 100mW.

[0079] In one embodiment, as shown in FIG1, the diamond chip 40 further includes a long-pass filter 21, which is located between the first surface of the first substrate 31 of the photodetector 20 and the first surface of the first substrate 31. The long-pass filter 21 is used to filter out interference light that interferes with the photodetector 20 receiving the target fluorescence signal generated by the microwave excitation of the diamond 42 with NV color centers.

[0080] Specifically, the interfering light includes the excitation light generated by the laser source element 10 and the 575 nm defect fluorescence generated simultaneously by the microwave antenna 41 exciting the diamond 42 with NV color centers. Since the defect fluorescence itself does not respond to changes in the magnetic field, it cannot be used as the sensing signal of the magnetic field sensor, and therefore is not the target fluorescence signal, and needs to be filtered out.

[0081] This invention improves the reception efficiency of the photodetector 20 for the target fluorescence signal by setting a long-pass filter 21 to filter out interference light other than the target fluorescence signal generated by the diamond 42 with NV color center under microwave excitation, thereby improving the sensitivity of the semiconductor device as a magnetic field sensor.

[0082] In one embodiment, the long-pass filter 21 has a cutoff frequency of 632 nanometers and a transmittance of 10 in the cutoff band. -6 It can filter out the defect fluorescence (NV0, neutral nitrogen vacancy center) generated by 532 nm green excitation light and 575 nm diamond 42 with NV color center, and reduce the interference of the target fluorescence signal (NV-, negative nitrogen vacancy center) at a wavelength of 635 nm emitted by diamond 42 with NV color center after microwave excitation.

[0083] In one embodiment, the long-pass filter 21 has a cutoff wavelength greater than 575 nm and less than 635 nm to filter out excitation light at 532 nm and defect fluorescence at 575 nm; the transmittance of the cutoff band is 10. -6 -10 -4 .

[0084] In one embodiment, the thickness of the long-pass filter 21 is 1 micrometer to 25 micrometers.

[0085] In one embodiment, the thickness of the diamond 42 with NV color centers is 1 micrometer to 700 micrometers.

[0086] In one embodiment, the microwave antenna 41 is composed of one or more layers of metal film.

[0087] In one embodiment, the microwave antenna 41 is composed of a multilayer metal film composite.

[0088] In one embodiment, the microwave antenna 41 is made of gold and / or silver.

[0089] In one embodiment, the thickness of the microwave antenna 41 is 30 nanometers to 1000 nanometers.

[0090] In one embodiment, the microwave transmission line 35 is a silicon surface transmission line.

[0091] In one embodiment, the microwave antenna 41 performs in-situ microwave excitation on the diamond 42, and the required driving power of the microwave antenna 41 is approximately 10mW.

[0092] In one embodiment, the material of the support structure 30 is silicon.

[0093] Specifically, using silicon materials can better adapt to the material supply and process equipment in mature MEMS processes, thereby improving the adaptability of the semiconductor devices to mass production using MEMS processes and increasing production efficiency.

[0094] In one embodiment, both the first substrate 31 and the second substrate 33 are four-inch silicon wafers.

[0095] Specifically, other suitable sizes and materials can also be selected as the first substrate 31 and the second substrate 33 according to requirements, all of which are within the protection scope of this invention.

[0096] In one embodiment, the projected area of ​​the first through hole 32 on the second surface is 0.25 square millimeters to 100 square millimeters.

[0097] In one embodiment, the thickness of the first substrate 31 is 300 micrometers to 700 micrometers.

[0098] In one embodiment, as shown in FIG1, a reflective metal layer 36 is provided on the sidewall of the first substrate 31, and the reflective metal layer 36 has a reflectivity of greater than or equal to 90% for the target fluorescence signal.

[0099] By setting the reflective metal layer 36, the present invention reflects the scattered laser and fluorescence back to the diamond 42 in the overall structure of the semiconductor device. This reduces the loss of the target fluorescence signal generated by the diamond 42 with NV color centers when excited by microwaves to a certain extent, thereby improving the intensity of the target fluorescence signal and further improving the sensitivity achievable by the quantum magnetic field sensor of the same volume.

[0100] In one embodiment, the thickness of the reflective metal layer 36 is 30 nanometers to 1000 nanometers.

[0101] In one embodiment, the reflective metal layer 36 is a single or multiple metal film with gold or silver deposited on its surface.

[0102] Specifically, the reflective metal layer 36 can be made of metal, which can serve as both a reflective layer for the target fluorescence signal to improve the collection efficiency of the target fluorescence signal and a material for the subsequent bonding of the first substrate 31 and the second substrate 33. Alternatively, a reflective layer made of other materials can be selected to reflect the target fluorescence signal, but the bonding effect of the first substrate 31 and the second substrate 33 may be poor, requiring an additional bonding layer to improve the bonding strength. Any deformation of these layers is within the protection scope of this invention.

[0103] In one embodiment, as shown in FIG1, the sidewall of the first through hole 32 is inclined at a preset angle θ to the first surface, and the diameter of the first through hole 32 on the first surface is larger than the diameter of the first through hole 32 on the second surface.

[0104] By using the inclined design of the sidewall of the first through hole 32, the present invention can enable the photodetector 20 to collect the target fluorescence signal excited by the side of the diamond 42, unlike the diamond 42 magnetic field sensor in the prior art which can only collect the target fluorescence signal excited by the front of the diamond 42. This further reduces the loss of the target fluorescence signal, increases the target fluorescence signal intensity of the photodetector 20, and thus improves the sensitivity of the magnetic field sensor.

[0105] Specifically, the preset tilt angle θ is not equal to 90°. The specific tilt angle of the preset tilt angle θ can be designed according to actual needs to meet the requirements of the collection efficiency of the target fluorescence signal.

[0106] In one embodiment, the projected area of ​​the second through hole 34 on the second surface is 100 square micrometers to 25 square millimeters.

[0107] In one embodiment, the thickness of the second substrate 33 is 300 micrometers to 700 micrometers.

[0108] In one embodiment, the laser generated by the laser source element 10 coincides with the projection of the center point of the second through hole 34 and the center point of the microwave antenna 41 on the bottom surface of the diamond 42 with NV color centers onto the second surface.

[0109] This invention aligns the laser generated by the laser source element 10 with the center point of the second through hole 34, and the center point of the microwave antenna 41 on the bottom surface of the diamond 42 is also aligned with the center point of the second through hole 34. This allows the laser generated by the laser source element 10 to be aligned with the microwave antenna 41 during the semiconductor device fabrication process, avoiding the need for additional alignment and adjustment of the laser and microwave antenna 41 by external imaging equipment. This significantly reduces the size and weight required for the magnetic field sensor, further realizing the lightweight and miniaturization of the magnetic field sensor.

[0110] In one embodiment, the laser source element 10 is a light-emitting diode or a laser diode.

[0111] Specifically, the laser source element 10 may also adopt other suitable structures that can generate laser sources and can be integrated and fabricated using MEMS technology, all of which are within the protection scope of this invention.

[0112] In one embodiment, as shown in Figures 1-2, the laser diode is provided with a laser diode heat sink 11 to dissipate heat and improve the reliability of the laser diode.

[0113] In one embodiment, as shown in Figures 1-2, a laser diode is installed below the support structure 30 via a heat sink 54, which also dissipates heat from the semiconductor device.

[0114] The present invention provides a mounting space for the laser heat sink under the support structure 30 by setting a heat sink 54 and a laser diode heat sink 11 below the support structure 30, and at the same time, it improves the heat dissipation performance of the semiconductor device as a heat conduction component.

[0115] In one embodiment, as shown in FIG2, in the diamond chip 40, the electrical connection of the laser source element 10 includes the positive and negative connection lines of the laser diode as laser diode electrodes 55 to provide driving current; the electrical connection of the microwave excitation structure includes the input end, output end, and ground end of the microwave transmission line 35 to provide surface-transmitted radio frequency signals.

[0116] In one embodiment, as shown in FIG2, the electrical connection of the photodetector 20 includes a positive electrode connection line and a negative electrode connection line of the photodetector 20, which serve as photodetector electrodes 56 to provide a reverse bias voltage.

[0117] This invention enables the photodetector 20 to operate in photoconductive mode by connecting it to a reverse bias voltage, thereby achieving a wider bandwidth and faster response speed, and further improving the sensitivity and response speed of the magnetic field sensor.

[0118] In one embodiment, as shown in FIG1, the semiconductor device further includes a package 50 and a package lead 53. The package 50 is used to hermetically package the laser source element 10 and the diamond chip 40. One end of the package lead 53 is located inside the package 50 and forms corresponding electrical connections with the laser source element 10 and the diamond chip 40 through bonding leads 58. The other end of the package lead 53 is located outside the package 50 and leads out the corresponding electrical connections between the laser source element 10 and the diamond chip 40.

[0119] In one embodiment, as shown in FIG1, the encapsulation housing 50 includes a housing base 51 and a housing cover plate 52. Both the inner and outer surfaces of the encapsulation housing 50 are provided with a heat-conducting layer, and the heat-conducting layer is insulated from the housing pins 53.

[0120] This invention hermetically seals the semiconductor device with a package 50, effectively preventing moisture in the air from corroding the electrical pins of the semiconductor device and causing short circuits or open circuits, thus improving the reliability of the magnetic field sensor. At the same time, by setting a heat conduction layer, the heat conduction efficiency of the semiconductor device can be improved, thereby improving heat dissipation capacity and enhancing the operational reliability of the semiconductor device.

[0121] Preferably, the heat-conducting layer is a non-magnetic or low-magnetic material to reduce the noise received by the photodetector 20 of the target fluorescence signal.

[0122] In one embodiment, the thickness of the heat-conducting layer is 1 micrometer to 10 micrometers.

[0123] In one embodiment, the heat-conducting layer is a metal.

[0124] In one embodiment, the heat-conducting layer is a single-layer or multi-layer metal film made of gold or nickel.

[0125] In one embodiment, the housing pin 53 is an RF pin.

[0126] In one embodiment, the electrical signal frequency that can be transmitted through the housing pin 53 is DC-4GHz.

[0127] In one embodiment, the encapsulation leakage rate inside the encapsulation housing 50 is less than 5 × 10⁻⁶. -9 (Pa·m 3 ) / s.

[0128] In one embodiment, as shown in FIG1, the semiconductor device further includes a printed circuit board 57; the printed circuit board 57 is electrically connected to the housing pins 53 of the semiconductor device for transmitting electrical signals between the laser source element 10, the photodetector 20 and the microwave excitation structure.

[0129] In one embodiment, the printed circuit board 57 includes a transimpedance amplifier circuit, a lock-in amplifier, and a data processor. One end of the transimpedance amplifier is electrically connected to the housing pin 53, and the other end of the transimpedance amplifier is electrically connected to one end of the lock-in amplifier. The other end of the lock-in amplifier is electrically connected to the data processor. The transimpedance amplifier circuit is used for the transmission of radio frequency signals from the microwave excitation structure and the voltage conversion of the photocurrent signal obtained by the photodetector 20 to obtain a voltage signal. The lock-in amplifier is used to demodulate the voltage signal obtained by the transimpedance amplifier circuit to obtain a demodulated signal. The data processor is used to perform microwave frequency sweep processing on the demodulated signal obtained by the lock-in amplifier to obtain the magnetic noise spectral density at different frequencies.

[0130] In one embodiment, the bandwidth of the lock-in amplifier is 1 kHz.

[0131] This invention optimizes the sensitivity of semiconductor devices as quantum magnetic field sensors by adjusting the bandwidth of the lock-in amplifier. Specifically, a smaller bandwidth of the lock-in amplifier results in better sensitivity.

[0132] In one embodiment, an external power source is electrically connected to the printed circuit board 57 to power the printed circuit board 57.

[0133] In one embodiment, the working principle of the semiconductor device as a magnetic sensor for measuring magnetic field changes is as follows:

[0134] Laser-excited NV color centers in diamond 42 to generate fluorescence: When the semiconductor device is working as an integrated quantum magnetic sensor, it powers the printed circuit board 57 through an external power supply, thereby providing a constant current drive to the laser diode (laser source element 10) to generate green laser to laser pump the NV color centers in diamond 42. The particles in the ground state of the NV color centers in diamond 42 are pumped to the excited state and return to the ground state through radiative transition, while generating fluorescence.

[0135] Different magnetic fields cause different changes in the photodetector magnetic resonance frequency between the two ground state energy levels of the NV color center, which are split by Zeeman: When a bias magnetic field (the measured magnetic field) is applied to the semiconductor device, the electron spin ground state in the NV color center, which is in the NV-charge state, changes from the m-spin state, which was originally in the degenerate state. s =Zeeman splitting occurs at the ±1 energy level, causing m s =+1 and m s = -1 The photodetector magnetic resonance frequency between the two energy levels produces 2γB NV The offset (difference), where γ is the gyromagnetic ratio, B NV This is the projection component of the bias magnetic field along the NV color center axis;

[0136] Microwaves modulate the fluorescence signal generated by the excited NV color center: by the change of the photodetector magnetic resonance frequency corresponding to the resonance between the spin precession frequency (νL) of the NV color center and the microwave frequency, the magnitude of the bias magnetic field projected onto the NV color center axis can be obtained; the modulated radio frequency signal generated by the microwave antenna 41 as a microwave source is transmitted to the bottom surface of the diamond 42 through the shell pin 53, bonding wire 58 (metal), microwave transmission line 35 and microwave antenna 41 in sequence, and simultaneously performs in-situ microwave driving on the NV color center of the diamond 42 excited by the laser. Under the combined action of the laser, photodetector magnetic resonance occurs, thereby modulating the target fluorescence signal generated by the diamond 42 by the microwave. After passing through the long-pass filter 21, the target fluorescence signal modulated by microwave resonance is received by the photodetector 20 and converted into a current signal;

[0137] The modulated signal received by photodetector 20 is demodulated, filtered, and converted into a sensitivity spectrum. The current signal of photodetector 20 is transmitted through bonding wire 58 and shell pin 53 to the transimpedance amplifier circuit on the surface of printed circuit board 57, converted into a voltage signal, and output to lock-in amplifier. After demodulation by lock-in amplifier, it is transmitted to data processor (host computer) for data processing. Among them, microwave antenna 41 performs microwave frequency sweep processing on the NV color center of diamond 42 from 2.4GHz to 3.2GHz. Finally, the demodulated signal of the target fluorescence signal of the NV color center of diamond 42 in four axes after microwave modulation and lock-in amplifier demodulation (representing the number of photoelectrons of the target fluorescence signal corresponding to different microwave resonant frequencies) can be obtained. One demodulated signal is selected (preferably the demodulated signal with the largest slope to achieve the best...) The resonance frequency (energy level shift) of the high-sensitivity signal is used as the optical detection magnetic resonance frequency during magnetic measurement. The amplitude spectral density of the demodulated signal can be obtained by performing a Fourier transform on the demodulated voltage signal within 1 second of the lock-in amplifier. The slope of the demodulated signal (the rate of change between the intensity change of the target fluorescence signal and the change of the microwave resonance frequency) and the gyromagnetic ratio γ (γ = νL / B, where B is the external magnetic field and νL is the spin precession frequency of the NV color center, which changes equal to the microwave resonance frequency) are then converted into the magnetic noise spectral density of the system, serving as a parameter characterizing the sensitivity of the Diamond 42 quantum magnetometer. Finally, the spectrum of the magnetic detection sensitivity at different spectral frequencies after Fourier transform of the demodulated signal, as shown in Figure 3, is obtained. A sensitivity of 5.5 nT·Hz is achieved within the spectral frequency range of 10-1000 Hz. -1 / 2 Magnetic detection sensitivity.

[0138] The present invention also provides a method for fabricating a semiconductor device, the method being used to fabricate any of the semiconductor devices described above, the method comprising:

[0139] Step 1: Provide a support structure 30 with a microwave transmission line 35 and a diamond 42 with an NV color center with a microwave antenna 41;

[0140] Step 2: The bottom surface of the diamond 42 with the NV color center, which is equipped with the microwave antenna 41, is disposed on the third surface of the support structure 30 through the first through hole 32, so that the microwave antenna 41 and the microwave transmission line 35 are coupled together, and the projection of the center point of the microwave antenna 41 and the center point of the second through hole 34 on the second surface coincides.

[0141] Step 3: The long-pass filter 21 and the photodetector 20 are sequentially mounted on the first through hole 32 on the first surface to obtain the diamond chip 40;

[0142] Step 4: Fix the laser source element 10 and the diamond chip 40 onto the housing base 51, and fix the diamond chip 40 onto the laser source element 10, so that the laser generated by the laser source element 10 coincides with the projection of the center of the microwave antenna 41 onto the second surface of the support structure 30; set bonding leads 58 to electrically connect the diamond chip 40 and the laser source element 10 to the housing pins 53 of the housing base 51; set the housing cover plate 52 and the housing base 51 to hermetically seal to obtain the encapsulated housing 50, so that the laser source element 10 and the diamond chip 40 are hermetically sealed inside the encapsulated housing 50.

[0143] The method for fabricating the semiconductor device of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the above order does not strictly represent the order of the semiconductor device fabrication method protected by the present invention, and those skilled in the art can make changes according to the actual fabrication steps.

[0144] First, in step 1, a support structure 30 with a microwave transmission line 35 and a diamond 42 with an NV color center with a microwave antenna 41 are provided.

[0145] In one embodiment, the method for fabricating the support structure 30 on which the microwave transmission line 35 is provided includes:

[0146] A first substrate 31 is provided, the first substrate 31 including opposing first and second surfaces;

[0147] As shown in FIG4, a first barrier layer 61 is provided on the first surface of the first substrate 31, and a second barrier layer 62 is provided on the second surface of the first substrate 31.

[0148] As shown in Figures 5 and 6, the first barrier layer 61, the first substrate 31 and the second barrier layer 62 are etched to obtain a first through hole 32 that penetrates the first barrier layer 61, the first substrate 31 and the second barrier layer 62.

[0149] As shown in Figure 7, a reflective metal layer 36 is covered on the sidewall surface of the first through hole 32 (the thickness of the reflective metal layer 36 in the figure is enlarged for display purposes and is not shown as a ratio to the actual thickness of the first substrate 31 and the first barrier layer 61).

[0150] A second substrate 33 is provided, the second substrate 33 including opposing third and fourth surfaces;

[0151] As shown in FIG8, a third barrier layer 63 is provided on the third surface of the second substrate 33;

[0152] As shown in Figures 8 and 9, a patterned microwave transmission line 35 is provided on the third barrier layer 63;

[0153] As shown in Figures 10-11, the microwave transmission line 35, the third barrier layer 63 and the second substrate 33 are etched to obtain a second through hole 34 that penetrates the microwave transmission line 35, the third barrier layer 63 and the second substrate 33.

[0154] As shown in Figure 12, the second surface of the first substrate 31 is bonded to the third surface of the second substrate 33, so that the central axis of the first through hole 32 and the second through hole 34 coincide, thus obtaining the support structure 30 with microwave transmission line 35.

[0155] The present invention avoids the problem of gold-silicon eutectic during the subsequent bonding of the first substrate 31 and the second substrate 33 by setting a first barrier layer 61, a second barrier layer 62 and a third barrier layer 63, thereby improving process yield and product reliability.

[0156] In one embodiment, the first barrier layer 61, the second barrier layer 62, and the third barrier layer 63 are all silicon dioxide.

[0157] In one embodiment, the diameter of the first through-hole 32 is slightly larger than the diameter of the diamond 42 with NV color centers, so that the diamond 42 with NV color centers can be placed on the third surface of the second substrate 33 through the first through-hole 32.

[0158] In one embodiment, the method for obtaining the first via 32 is as follows: dry etching the first barrier layer 61 to obtain a patterned first barrier layer 61 on the first surface of the first substrate 31; depositing a patterned mask layer on the patterned first barrier layer 61 and the exposed first surface; performing wet etching on the first substrate 31 using the mask layer as a mask, and obtaining the first via 32 with a preset tilt angle θ between the sidewall and the first surface through anisotropic wet etching.

[0159] In one embodiment, the mask layer is silicon nitride.

[0160] By using silicon nitride as a mask layer, this invention can protect the area outside the first via 32 from corrosion, improve the morphological accuracy of the first via 32 obtained after the process, and improve the overall device reliability.

[0161] In one embodiment, potassium hydroxide is used to perform anisotropic wet etching on the first substrate 31.

[0162] In one embodiment, an anisotropic etching method is used to obtain a preset tilt angle θ of 54.7° between the sidewall of the first through hole 32 and the first surface.

[0163] By setting a preset tilt angle θ of 54.7°, the present invention can maximize the collection efficiency of the target fluorescence signal while ensuring the fixed protection of the first through hole 32 for the diamond 42.

[0164] Specifically, the preset tilt angle θ can also be set to other suitable angles as needed.

[0165] In one embodiment, when a reflective metal layer 36 is covered on the sidewall surface of the first via 32, the reflective metal layer 36 simultaneously covers all exposed surfaces of the first substrate 31.

[0166] The present invention uses a reflective metal layer 36 deposited on all exposed surfaces of the first substrate 31, which can be used for subsequent bonding of the first substrate 31 and the second substrate 33. At the same time, it avoids the need for patterned deposition of mask layers or etching processes required to set the reflective metal layer 36 only on the sidewall of the first via 32, thus improving process efficiency.

[0167] In one embodiment, the method for forming a patterned microwave transmission line 35 on the third barrier layer 63 includes: performing photolithography to obtain a patterned photoresist; depositing a microwave metal layer 65, filling the gaps between the patterned photoresist with metal, and removing the photoresist and the metal deposited on the photoresist by lift-off (peel-off process), leaving only the patterned microwave metal layer 65 filling the gaps between the patterned photoresist, to obtain the patterned microwave transmission line 35; or as shown in FIG8, first depositing a microwave metal layer 65 to cover the third barrier layer 63; forming a photoresist on the deposited microwave metal layer 65 and performing photolithography to obtain a patterned photoresist; as shown in FIG9, using the patterned photoresist as a mask to etch the exposed microwave metal layer 65 to obtain the patterned microwave metal layer 65 as the microwave transmission line 35.

[0168] In one embodiment, the method for obtaining the second via 34 is as follows: first, photoresist is deposited on the microwave transmission line 35 and photolithography is performed to obtain patterned photoresist; then, the third barrier layer 63 and the second substrate 33 are dry etched using the patterned photoresist as a mask to obtain the second via 34.

[0169] In one embodiment, a method for preparing a diamond 42 with an NV color center and a microwave antenna 41 includes:

[0170] Offer a diamond of 42 with an NV color center;

[0171] As shown in Figure 13, a microwave metal film 64 is disposed on the bottom surface of the diamond 42 with NV color center. As shown in Figure 14, the microwave metal film 64 is patterned to obtain a microwave antenna 41.

[0172] In one embodiment, the metal film on the bottom surface of the diamond 42 with NV color centers is patterned by lift-off or dry etching to obtain the microwave antenna 41.

[0173] Specifically, the patterned shape distribution of the microwave antenna 41 can be simulated and designed. As shown in Figure 15, which is a top view of the patterned distribution of the microwave antenna 41, this patterned distribution makes the microwave field intensity distribution formed by the microwave antenna 41 on the surface of the diamond 42 more uniform, thereby improving the uniformity of the photodetector 20 receiving the target fluorescence signal and thus improving the sensitivity of the magnetic field sensor.

[0174] Then, proceed to step 2, as shown in Figure 16, the bottom surface of the diamond 42 with the NV color center and the microwave antenna 41 is disposed on the third surface of the support structure 30 through the first through hole 32, so that the microwave antenna 41 and the microwave transmission line 35 are coupled together, and the projection of the center point of the microwave antenna 41 and the center point of the second through hole 34 on the second surface coincides.

[0175] In one embodiment, a diamond 42 with an NV color center is placed on the third surface by reverse bonding, and the contacting microwave antenna 41 and microwave transmission line 35 are welded together to achieve a metal connection.

[0176] Next, proceed to step 3, as shown in Figures 17-18, by sequentially mounting the long-pass filter 21 and the photodetector 20 on the first through hole 32 of the first surface, thus obtaining the diamond chip 40.

[0177] In one embodiment, the long-pass filter 21 and the photodetector 20 are fixedly mounted on the first through hole 32 on the first surface by bonding or gluing.

[0178] In one embodiment, the long-pass filter 21 is prepared by depositing high-refractive-index material and low-refractive-index material on two surfaces of a glass sheet, respectively.

[0179] Specifically, the glass sheet has the same dimensions as the first substrate 31.

[0180] In one embodiment, the glass sheet is four inches.

[0181] Finally, in step 4, as shown in Figure 19, the laser source element 10 and the diamond chip 40 are fixed on the housing base 51, and the diamond chip 40 is fixed on the laser source element 10, so that the laser generated by the laser source element 10 coincides with the projection of the center of the microwave antenna 41 on the second surface of the support structure 30; as shown in Figure 20, bonding wires 58 are set to electrically connect the diamond chip 40 and the laser source element 10 to the housing pins 53 of the housing base 51; as shown in Figure 21, the housing cover plate 52 is hermetically sealed with the housing base 51 to obtain the encapsulated housing 50, so that the laser source element 10 and the diamond chip 40 are hermetically sealed inside the encapsulated housing 50.

[0182] In one embodiment, the laser source element 10 is fixed to the bottom of the package housing 50 by solder.

[0183] Specifically, the laser source element 10 can be assembled with the diamond chip 40 using various welding methods.

[0184] In one embodiment, the encapsulation housing 50 hermetically seals the laser source element 10, the photodetector 20, the support structure 30, the diamond 42 with NV color centers, and the microwave excitation structure by soldering or parallel sealing.

[0185] This invention provides hermetic packaging of semiconductor devices using a packaging shell 50, which effectively prevents short circuits or open circuits in electrical pins caused by moisture in the air, thereby improving the reliability of the magnetic field sensor.

[0186] In one embodiment, as shown in FIG22, the packaged casing 50 and the printed circuit board 57 are assembled by pin soldering to achieve electrical connection with the printed circuit board 57.

[0187] In summary, the semiconductor device and its fabrication method of this invention can achieve miniaturized, portable magnetic field sensors by designing a semiconductor device integrating a laser source and a diamond chip, using standard MEMS technology. This allows for mass production, reducing production costs, and achieving high sensitivity while maintaining a small size, which is beneficial for applications in wearable and handheld products. Furthermore, by setting the microwave antenna of the laser source and diamond chip within the semiconductor device, a through-hole structure for direct alignment using standard semiconductor processes is achieved, enabling high-precision, small-volume alignment of the microwave antenna and laser source, improving the flexibility and reliability of the magnetic field sensor. Additionally, the inclined sidewall design of the first through-hole enables the photodetector to collect the target fluorescence signal generated by the diamond's side excitation, improving the photodetector's fluorescence collection efficiency and thus enhancing the sensitivity of the magnetic field sensor. Finally, the long-pass filter and reflective metal layer reduce the loss of the target fluorescence signal generated by microwave excitation of the diamond with NV color centers and reduce interference signals, further improving the sensitivity of the quantum magnetic field sensor within the same volume.

[0188] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0189] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A semiconductor device, characterized in that, The semiconductor device includes: a laser source element and a diamond chip; The diamond chip includes a photodetector, a support structure, a diamond with NV color centers, and a microwave excitation structure. The support structure includes a first substrate and a second substrate. The first substrate includes opposing first surfaces, a second surface, and a first through-hole penetrating the first surface and the second surface. The second substrate includes opposing third surfaces, a fourth surface, and a second through-hole penetrating the third surface and the fourth surface. The projected area of ​​the first through-hole on the second surface is greater than or equal to the projected area of ​​the diamond with NV color centers on the second surface, and the projected area of ​​the second through-hole on the second surface is less than the projected area of ​​the diamond with NV color centers on the second surface. The microwave excitation structure includes a microwave antenna and a microwave transmission line. The microwave transmission line is located on the third surface of the second substrate where the second through hole is not provided. The microwave antenna is located on the diamond bottom surface with NV color centers. The diamond bottom surface with NV color centers is mounted on the second through hole on the third surface through the first through hole. The microwave antenna and the microwave transmission line are coupled together. The laser source element is located below the fourth surface of the second substrate and is used to generate a laser that penetrates the second via from the fourth surface to reach the diamond with NV color centers; the photodetector is located on the first surface of the first substrate and is used to receive the target fluorescence signal generated by the microwave excitation of the diamond with NV color centers by the microwave antenna and convert the target fluorescence signal into a photocurrent signal.

2. The semiconductor device according to claim 1, characterized in that, The laser source element generates a laser wavelength of 450 nanometers to 570 nanometers.

3. The semiconductor device according to claim 1 or 2, characterized in that, The diamond chip also includes a long-pass filter, which is located between the first surfaces of the first substrate of the photodetector box. The long-pass filter is used to filter out interference light that interferes with the photodetector's reception of the target fluorescence signal generated by the microwave excitation of the diamond with NV color centers.

4. The semiconductor device according to claim 1, characterized in that, The first substrate has a reflective metal layer on its sidewall, and the reflective metal layer has a reflectivity of greater than or equal to 90% for the target fluorescence signal.

5. The semiconductor device according to claim 1, characterized in that, The sidewall of the first through hole forms a preset inclination angle with the first surface, and the diameter of the first through hole on the first surface is larger than the diameter of the first through hole on the second surface.

6. The semiconductor device according to claim 1, characterized in that, The laser generated by the laser source element coincides with the projection of the center point of the second through hole and the center point of the microwave antenna with the NV color center on the second surface.

7. The semiconductor device according to claim 1, characterized in that, The semiconductor device further includes a package and package leads. The package is used to hermetically seal the laser source element and the diamond chip. One end of the package lead is located inside the package and forms corresponding electrical connections with the laser source element and the diamond chip through bonding leads. The other end of the package lead is located outside the package and leads out the corresponding electrical connections between the laser source element and the diamond chip.

8. A method for fabricating a semiconductor device, characterized in that, The preparation method is used to prepare the semiconductor device according to any one of claims 1-7, and the preparation method includes: Provides a support structure with microwave transmission lines and a diamond with NV color centers equipped with a microwave antenna; The bottom surface of the diamond with the NV color center, which is equipped with a microwave antenna, is disposed on the third surface of the support structure through the first through hole of the support structure, so that the microwave antenna and the microwave transmission line are coupled together, and the projection of the center point of the microwave antenna and the center point of the second through hole on the second surface coincides. The long-pass filter and the photodetector are sequentially mounted on the first through hole of the first surface to obtain a diamond chip. The laser source element and the diamond chip are fixed on the housing base, and the diamond chip is fixed on the laser source element, so that the laser generated by the laser source element coincides with the projection of the center of the microwave antenna on the second surface of the support structure; bonding wires are provided to electrically connect the diamond chip and the laser source element to the housing pins of the housing base; a housing cover plate is provided and hermetically sealed with the housing base to form a packaged housing, so that the laser source element and the diamond chip are hermetically sealed inside the packaged housing.

9. The method for fabricating a semiconductor device according to claim 8, characterized in that, The method for fabricating the support structure provided with the microwave transmission line includes: A first substrate is provided, the first substrate including opposing first and second surfaces; A first barrier layer is disposed on a first surface of the first substrate, and a second barrier layer is disposed on a second surface of the first substrate; Etch the first barrier layer, the first substrate, and the second barrier layer to obtain a first through-hole penetrating the first barrier layer, the first substrate, and the second barrier layer; A reflective metal layer is applied to the sidewall surface of the first through hole; A second substrate is provided, the second substrate including opposing third and fourth surfaces; A third barrier layer is disposed on the third surface of the second substrate; A patterned microwave transmission line is provided on the third barrier layer; The microwave transmission line, the third barrier layer, and the second substrate are etched to obtain a second through-hole penetrating the microwave transmission line, the third barrier layer, and the second substrate; The second surface of the first substrate is bonded to the third surface of the second substrate, so that the central axis of the first through hole and the second through hole coincide, thus obtaining a support structure with microwave transmission lines.

10. The method for fabricating a semiconductor device according to claim 9, characterized in that, The method for obtaining the first via is as follows: dry etching the first barrier layer to obtain a patterned first barrier layer on the first surface of the first substrate; depositing a patterned mask layer on the patterned first barrier layer and the exposed first surface; performing wet etching on the first substrate using the mask layer as a mask, and obtaining a first via with a preset tilt angle between the sidewall and the first surface through anisotropic wet etching.

Images