MEMS atomic gas chamber with magnetic shielding layer and preparation method of MEMS atomic gas chamber

Abstract

The invention discloses an MEMS atomic gas chamber with a magnetic shielding layer and a preparation method thereof, and relates to the technical field of atomic clocks, the MEMS atomic gas chamber with the magnetic shielding layer comprises a silicon wafer, the silicon wafer is provided with a through hole penetrating through the upper end and the lower end, the upper side and the lower side of the silicon wafer are each provided with a transparent supporting layer, and a cavity is formed between the through hole and the two transparent supporting layers; alkali metal is placed in the cavity, a magnetic shielding layer is arranged on one side, away from the silicon wafer, of each transparent supporting layer, the magnetic shielding layer is a base material layer with a hollow cross-shaped array structure, and the hollow cross-shaped array structure corresponds to the position of the through hole. The MEMS atomic air chamber with the magnetic shielding layer is compact in structure, the requirements of a miniature atomic clock for miniaturization and high integration level are met, the shielding effect on an external magnetic field can be remarkably improved under the miniature scale, and batch production of multiple MEMS atomic air chambers can be achieved through the preparation method.

Description

Technical Field

[0001] This invention relates to the field of atomic clock technology, and in particular to a MEMS atomic gas cell with a magnetic shielding layer and its preparation method. Background Technology

[0002] An atomic clock is a device that achieves high-precision time measurement based on the frequency stability of atomic transitions, and it is widely used in navigation, communication, scientific research, and other fields. With the ever-increasing demand for high-precision time and frequency, the miniaturization and integration of atomic clocks have become key research directions. Miniature atomic clocks, due to their small size, low power consumption, and high precision, have broad application prospects in high-end consumer electronics, communication equipment, and deep space exploration. However, the practical application of miniature atomic clocks still faces a series of technical challenges, particularly in effectively shielding them from external magnetic field interference.

[0003] In traditional atomic clock designs, external magnetic fields affect atomic transitions within the atomic chamber, leading to frequency instability and measurement errors, thus reducing the clock's accuracy. To mitigate this magnetic interference, current technologies typically employ magnetic shielding using materials such as metal shielding or ferrite.

[0004] While these methods mitigate the effects of external magnetic fields to some extent, they still have several limitations. 1. Traditional magnetic shielding materials are bulky, making them unsuitable for miniaturization. Existing metal shields and ferrite materials, although offering some magnetic shielding, are too large to meet the miniaturization and high integration requirements of micro atomic clocks. 2. Insufficient magnetic shielding effectiveness. Traditional shielding materials cannot effectively isolate external magnetic fields from interfering with the atomic gas chamber within a micro-cell. As the size of the gas chamber shrinks, the shielding effectiveness of traditional materials decreases significantly, failing to meet the requirements of high-precision timing. 3. Significant challenges exist in integrated fabrication technology. Existing technologies face issues of precision and material compatibility in the design of micro atomic gas chambers, making it difficult to achieve high-precision and high-integration fabrication. Furthermore, existing technologies may struggle to guarantee consistency and efficiency in mass production, limiting the feasibility of large-scale manufacturing. Summary of the Invention

[0005] To address the above technical problems, this invention provides a MEMS atomic gas cell with a magnetic shielding layer and its fabrication method. The structure is compact, meeting the requirements of miniaturization and high integration for micro atomic clocks. It can significantly improve the shielding effect against external magnetic fields at the microscale and enables the mass production of multiple MEMS atomic gas cells.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a MEMS atomic gas chamber with a magnetic shielding layer, comprising a silicon wafer, wherein a through hole is provided on the silicon wafer extending through both the top and bottom ends, and a transparent support layer is provided on both the top and bottom sides of the silicon wafer, forming a cavity between the through hole and the two transparent support layers, wherein an alkali metal is placed in the cavity, and a magnetic shielding layer is provided on the side of each transparent support layer away from the silicon wafer, wherein the magnetic shielding layer is a substrate layer with a hollow cross-shaped array structure, and the hollow cross-shaped array structure corresponds to the position of the through hole.

[0007] Preferably, the two transparent support layers are bonded to the upper and lower sides of the silicon wafer, respectively.

[0008] Preferably, each of the magnetic shielding layers is deposited on the side of one of the transparent support layers away from the silicon wafer.

[0009] Preferably, the through hole is a cylindrical hole.

[0010] Preferably, the transparent support layer is a semiconductor glass layer.

[0011] Preferably, the substrate layer is made of metal.

[0012] Preferably, the metal material is copper.

[0013] Preferably, the alkali metal is rubidium or cesium.

[0014] This invention also provides a method for fabricating a MEMS atomic gas cell with a magnetic shielding layer, comprising the following steps: Step 1: Process multiple through holes penetrating both the top and bottom ends on the silicon wafer; Step 2: Deposit the substrate layer on top of the transparent support layer, and place the transparent support layer on top of the silicon wafer to form an intermediate assembly; Step 3: Flip the intermediate assembly so that the transparent support layer is located below the silicon wafer, and place the alkali metal in each of the through holes; Step 4: Deposit the substrate layer on top of the other transparent support layer, and place the transparent support layer on top of the silicon wafer; Step 5: Process multiple hollow cross-shaped array structures in each of the substrate layers to form the magnetic shielding layer, such that each hollow cross-shaped array structure corresponds to one of the through holes to form an atomic gas chamber assembly; Step 6: Cut the atomic gas chamber assembly to prepare multiple MEMS atomic gas chambers.

[0015] Preferably, in step one, multiple through holes are fabricated on the silicon wafer using photolithography and reactive ion etching.

[0016] The present invention achieves the following technical effects compared to the prior art: In this invention, a through-hole is formed on the silicon wafer of the MEMS atomic gas cell with a magnetic shielding layer, penetrating both the top and bottom ends. Transparent support layers are provided on both the top and bottom sides of the silicon wafer, forming a cavity between the through-hole and the two transparent support layers. An alkali metal is placed in the cavity. A magnetic shielding layer is provided on the side of each transparent support layer away from the silicon wafer. The magnetic shielding layer is a substrate layer with a hollowed-out cross-shaped array structure, corresponding to the position of the through-hole. In this invention, the hollowed-out cross-shaped array structure allows laser light to pass through, while the magnetic shielding layer has excellent magnetic field shielding effectiveness, effectively isolating external magnetic fields from interference with the atomic gas cell. Furthermore, the combination of the silicon wafer, transparent support layer, and magnetic shielding layer forms a compact atomic gas cell structure, meeting the miniaturization and high integration requirements of micro-atomic clocks. This significantly improves the shielding effect against external magnetic fields at a microscale, thereby ensuring the stability of the atomic state within the MEMS atomic gas cell and reducing interference from external magnetic fields on the accuracy of the atomic clock.

[0017] In the method for preparing MEMS atomic gas cells with magnetic shielding layers in this invention, an atomic gas cell assembly is first processed, and then the atomic gas cell assembly is cut to prepare multiple MEMS atomic gas cells. This invention adopts an integrated production process, which can realize the mass production of multiple MEMS atomic gas cells, which not only improves production efficiency, but also ensures the accuracy and consistency of each MEMS atomic gas cell. Attached Figure Description

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

[0019] Figure 1 A three-dimensional structural diagram of a MEMS atomic gas cell with a magnetic shielding layer provided for this invention; Figure 2 A top view of a MEMS atomic gas chamber with a magnetic shielding layer provided by the present invention; Figure 3 for Figure 2 Sectional view along the middle AA direction; Figure 4 A three-dimensional structural diagram of the atomic gas chamber assembly provided by the present invention; Figure 5 This is a top view of the atomic gas chamber assembly provided by the present invention; Figure 6 for Figure 5 Sectional view along the BB direction; Figure 7 A process flow diagram of the fabrication method of the MEMS atomic gas cell with a magnetic shielding layer provided by the present invention; Figure 8 Frequency response curve of the shielding effectiveness of the MEMS atomic gas cell with magnetic shielding layer provided by the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Silicon wafer; 2. Through-hole; 3. Transparent support layer; 4. Chamber; 5. Magnetic shielding layer; 6. Cross-shaped hole; 7. Alkali metal. Detailed Implementation

[0021] 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.

[0022] The purpose of this invention is to provide a MEMS atomic gas cell with a magnetic shielding layer and its preparation method. The structure is compact, which meets the requirements of miniaturization and high integration of micro atomic clocks. It can significantly improve the shielding effect against external magnetic fields at the microscale and can realize the mass production of multiple MEMS atomic gas cells.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1-3 As shown, this embodiment provides a MEMS atomic gas chamber with a magnetic shielding layer, including a silicon wafer 1. The silicon wafer 1 has through holes 2 extending through both the top and bottom ends. Transparent support layers 3 are provided on both the top and bottom sides of the silicon wafer 1. A cavity 4 is formed between the through holes 2 and the two transparent support layers 3. An alkali metal 7 is placed in the cavity 4. A magnetic shielding layer 5 is provided on the side of each transparent support layer 3 away from the silicon wafer 1. The magnetic shielding layer 5 is a substrate layer with a hollow cross-shaped array structure. The hollow cross-shaped array structure corresponds to the position of the through holes 2, thereby enabling the cavity 4 to transmit light.

[0025] In this embodiment, the magnetic shielding layer 5 is set on the transparent support layer 3 and has a hollow cross-shaped array structure corresponding to the position of the through hole 2. By adopting this micro-nano structure of hollow cross-shaped array structure, a metamaterial with special electromagnetic response is constructed, and finally the efficient magnetic shielding function that is difficult to achieve with traditional materials is realized. While ensuring light transmission, it has excellent magnetic field shielding performance and can effectively isolate the interference of external magnetic field on the atomic gas cell.

[0026] Furthermore, the combination of silicon wafer 1, transparent support layer 3, and magnetic shielding layer 5 forms a compact atomic cell structure, meeting the miniaturization and high integration requirements of micro atomic clocks. This significantly improves the shielding effect against external magnetic fields at the microscale, ensuring the stability of the atomic state within the MEMS atomic cell and reducing interference from external magnetic fields on the accuracy of the atomic clock. Simultaneously, the combination of silicon wafer 1, transparent support layer 3, and magnetic shielding layer 5 facilitates the integrated mass production of MEMS atomic cells.

[0027] In this embodiment, the two transparent support layers 3 are bonded to the upper and lower sides of the silicon wafer 1, respectively. The precise bonding process ensures a strong connection between the silicon wafer 1 and the transparent support layer 3, ensuring the airtightness of the atomic gas chamber, effectively preventing the entry of external gases or impurities, and further improving the accuracy and long-term stability of the atomic clock.

[0028] In this embodiment, each magnetic shielding layer 5 is deposited on the side of a transparent support layer 3 away from the silicon wafer 1. The deposition method ensures a strong bond between the magnetic shielding layer 5 and the transparent support layer 3, and makes the structure more compact.

[0029] In this specific embodiment, the through hole 2 is a cylindrical hole.

[0030] Specifically, the transparent support layer 3 is a semiconductor glass layer.

[0031] Specifically, the substrate layer is made of metal. In this embodiment, the metal is copper, meaning the substrate layer in this embodiment is a metal layer.

[0032] Specifically, the alkali metal 7 is rubidium or cesium.

[0033] like Figure 7 As shown, this embodiment also provides a method for fabricating a MEMS atomic gas cell with a magnetic shielding layer, including the following steps: Step 1: Process multiple through holes 2 through both the top and bottom ends on the silicon wafer 1. Specifically, the multiple through holes 2 are evenly distributed on the silicon wafer 1.

[0034] Step 2: A substrate layer is disposed on the upper part of a transparent support layer 3. The transparent support layer 3 is disposed on the upper part of the silicon wafer 1 to form an intermediate assembly.

[0035] Specifically, a substrate layer is deposited on top of a transparent support layer 3, and the transparent support layer 3 with the deposited substrate layer is bonded to the top of the silicon wafer 1.

[0036] Step 3: Flip the intermediate assembly so that the transparent support layer 3 is located below the silicon wafer 1, and place the alkali metal 7 in each through hole 2.

[0037] Step 4: Set a substrate layer on top of another transparent support layer 3, and place the transparent support layer 3 on top of the silicon wafer 1.

[0038] Specifically, a substrate layer is deposited on top of another transparent support layer 3, and the other transparent support layer 3 with the deposited substrate layer is bonded to the top of the silicon wafer 1.

[0039] In this specific embodiment, the transparent support layer 3 and the silicon wafer 1 can be bonded using techniques such as anodic bonding or eutectic bonding.

[0040] Step 5: Multiple hollow cross-shaped array structures are processed on each substrate layer to form a magnetic shielding layer 5, so that each hollow cross-shaped array structure corresponds to a through hole 2 to form an atomic gas chamber assembly.

[0041] like Figures 4-6 As shown, the silicon wafer 1 of the atomic gas chamber assembly has multiple through holes 2, each through hole 2 forming a cavity 4 with two transparent support layers 3, each cavity 4 containing an alkali metal 7, and each magnetic shielding layer 5 having multiple hollow cross-shaped array structures corresponding one-to-one with the through holes 2.

[0042] Specifically, a hollow cross-shaped array structure is etched on each magnetic shielding layer 5, so that the side of the transparent support layer 3 close to the magnetic shielding layer 5 is exposed, so that the cavity 4 can be light-transmitted, thus achieving the magnetic field shielding function while ensuring light transmission.

[0043] In this specific embodiment, the processing flow of the hollow cross-shaped array structure can be summarized as follows: photoresist coating on the substrate layer → exposure pattern → development to form a mask → dry etching → removal of photoresist.

[0044] Step 6: Cut the atomic gas chamber assembly to prepare multiple MEMS atomic gas chambers.

[0045] Specifically, using precise cutting technology, the atomic gas chamber assembly is divided into multiple independent individuals. Each MEMS atomic gas chamber has a cavity 4 and two hollowed-out cross-shaped array structures corresponding to the upper and lower ends of the cavity 4.

[0046] In step one, multiple through holes 2 are fabricated on silicon wafer 1 using photolithography and reactive ion etching.

[0047] The entire process of fabricating multiple through holes 2 on silicon wafer 1 can be summarized as follows: silicon wafer preparation → photoresist coating → exposure pattern → development to form a mask → baking → dry etching → photoresist removal.

[0048] Specifically, the process includes the following steps: Step 1, silicon wafer preparation, aims to obtain clean, dry silicon wafers with no surface defects to ensure good adhesion of the photoresist. The specific operations are: Chemical cleaning: Using the standard RCA cleaning method to remove organic and inorganic contaminants and metal ions. Dehydration baking: Baking the silicon wafer on a hot plate at 150-200℃ for 5-10 minutes to remove surface moisture; this step is crucial to prevent photoresist from peeling off.

[0049] The second step, photoresist coating, aims to uniformly coat the silicon wafer with a defect-free photoresist film of a certain thickness, serving as a mask for subsequent etching. The specific steps are as follows: Coating: Use a spin coater for spin coating. First, spin at low speed (500-1000 rpm) to spread the photoresist, then spin at high speed (2000-4000 rpm) to achieve the target thickness. Pre-baking: Bake on a hot plate at 90-110℃ for 60-90 seconds. The purpose is to evaporate most of the solvent in the photoresist, allowing it to solidify and stabilize.

[0050] The third step, exposure, aims to selectively irradiate the photoresist using ultraviolet light through a photomask, altering the chemical properties of the irradiated area. Specifically, a chrome photomask with a circular aperture array is aligned with the silicon wafer. A contact / proximity lithography machine or a stepper lithography machine is used to irradiate the wafer with ultraviolet light of a specific wavelength (e.g., 365nm i-line, 405nm h-line). For positive photoresists, the irradiated area undergoes a photochemical reaction, becoming soluble in the developer.

[0051] The fourth step, development, aims to dissolve the photoresist in the exposed areas (for positive photoresist), precisely transferring the pattern from the mask to the photoresist layer and exposing the silicon areas to be etched. The specific procedure involves immersing the exposed silicon wafer in a specific developer (such as TMAH series developers, for example, AZ 400K diluent) for a certain period. Rinse quickly with deionized water to stop the development reaction. Dry the silicon wafer with nitrogen gas.

[0052] Step 5, baking, aims to further evaporate any residual solvent in the photoresist, improving its mechanical strength and etching resistance. This step is crucial for deep silicon etching, preventing mask failure during prolonged etching. Specifically, bake on a hot plate at 120-140℃ for 5-10 minutes.

[0053] Step 6, dry etching, aims to transfer the pattern from the photoresist layer onto the silicon wafer using anisotropic etching technology, forming high aspect ratio vertical vias. Specifically, it employs deep reactive ion etching, particularly the Bosch process. The Bosch process consists of multiple cycles, each including: Etching step: SF6 gas is introduced to generate fluorine radicals (F*) for rapid isotropic etching of silicon. Passivation step: C4F8 gas is introduced to deposit a thin layer of fluorinated carbon passivation across the entire chamber surface (including sidewalls and bottom). Cycle repeat: In the next etching step, SF6 plasma preferentially bombards and removes the passivation layer at the bottom, continuing vertical etching of silicon, while the passivation layer on the sidewalls is retained, thus achieving anisotropic high aspect ratio etching.

[0054] Step 7: Photoresist Removal. The purpose is to completely remove any remaining photoresist mask from the silicon wafer after etching. The specific steps are: Oxygen Plasma Ashing: The silicon wafer is placed in a plasma photoresist remover, and oxygen is introduced to generate oxygen plasma that oxidizes the organic photoresist into volatile gases (such as CO2, H2O). Wet Cleaning: A final cleaning is performed using solvents such as acetone and N-methylpyrrolidone to ensure absolute surface cleanliness.

[0055] The hollow cross-shaped array structure includes multiple cross-shaped holes 6. The electromagnetic shielding mechanism of the hollow cross-shaped array structure is based on the LC resonance principle and is calculated using the following formula.

[0056] Equivalent Inductance L eq The calculation formula is as follows: Equivalent capacitance C eq The calculation formula is as follows: resonant frequency f r The calculation formula is as follows: in, μ 0 The permeability of free space, ε 0 The vacuum permittivity, ε r The relative permittivity of the transparent support layer, L The arm length of the cross-shaped hole 6, W The arm width of the cross-shaped hole 6, D The distance between any two adjacent cross-shaped holes 6 t The thickness of the magnetic shielding layer 5 is given.

[0057] When the thickness of the magnetic shielding layer 5 tWhen the value is constant, the resonant frequency can be precisely controlled by adjusting the specific dimensions of the hollowed-out cross-shaped array structure. Specifically, the arm length of the cross-shaped hole 6 can be adjusted. L、 Arm width of cross-shaped hole 6 W and the spacing between any two adjacent cross-shaped holes 6 D The value of is adjusted. Simultaneously, adjusting the parameters of the cross-shaped aperture 6 allows for the adjustment of visible light transmittance.

[0058] The alkali metal 7 in the MEMS atomic cell is rubidium, the substrate layer is a copper layer, and the transparent support layer 3 is a semiconductor glass layer. The target frequency for magnetic field shielding is designed; the typical operating frequency of a rubidium atomic clock is 4.5963 GHz.

[0059] In this specific embodiment, the parameters of the first rubidium atomic clock are: the arm length of the cross-shaped aperture 6. L The arm width of the cross-shaped hole 6 is 5mm. W The distance between any two adjacent cross-shaped holes 6 is 2mm. D The thickness of the magnetic shielding layer 5 is 3mm. t The relative permittivity of the semiconductor glass layer is 200nm. ε r =5, vacuum permittivity ε 0 =8.854×10 -12 F / m, vacuum permeability μ 0 =4π×10 -7 H / m.

[0060] Calculate equivalent inductance L eq Equivalent capacitance C eq and resonant frequency f r : L eq =6.47nH, C eq =59fF, f r =4.596GHz. As can be seen, the calculated result is in excellent agreement with the typical operating frequency of a rubidium atomic clock, thus realizing the design of the magnetic field shielding structure for the target frequency.

[0061] In another specific embodiment, the parameters of the second rubidium atomic clock are: the arm length of the cross-shaped aperture 6. L The arm width of the cross-shaped hole 6 is 8mm. W The distance between any two adjacent cross-shaped holes 6 is 1.138 mm. D The thickness of the magnetic shielding layer 5 is 5mm. tThe relative permittivity of the semiconductor glass layer is 200nm. ε r =5, vacuum permittivity ε 0 =8.854×10 -12 F / m, vacuum permeability μ 0 =4π×10 -7 H / m.

[0062] Calculate equivalent inductance L eq Equivalent capacitance C eq and resonant frequency f r : L eq =10.2nH, C eq =11.46fF, f r =4.5963GHz. As can be seen, the calculated result is in excellent agreement with the typical operating frequency of a rubidium atomic clock, thus realizing the design of the magnetic field shielding structure for the target frequency.

[0063] like Figure 8 As shown, taking the rubidium atomic clock with the first parameter mentioned above as an example, the shielding effectiveness frequency response curve was obtained by full-wave electromagnetic simulation using CST Microwave Studio. In this embodiment, the hollow cross-shaped array structure of the above dimensions designed achieves a shielding effectiveness of -42.7 dB at the target frequency of 4.5963 GHz of the rubidium atomic clock. At the same time, experimental tests show that it can maintain 81.5% visible light transmittance.

[0064] As can be seen, through silicon wafer micromachining technology, the atomic gas chambers can be miniaturized, and the precise control of the gas chamber structure meets the requirements of high integration and high-precision processing. The integrated processing technology enables multiple functional modules to be implemented on the same platform, optimizing the overall design and manufacturing process. Furthermore, the precise cutting process allows the atomic gas chamber assembly to be efficiently divided into multiple independent MEMS atomic gas chambers, significantly improving manufacturing consistency and stability.

[0065] In this embodiment, the method for fabricating a MEMS atomic gas cell with a magnetic shielding layer first processes an atomic gas cell assembly, and then cuts the atomic gas cell assembly to prepare multiple MEMS atomic gas cells. This embodiment adopts an integrated production process, which can realize the mass production of multiple MEMS atomic gas cells, which not only improves production efficiency, but also ensures the accuracy and consistency of each MEMS atomic gas cell.

[0066] In summary, this embodiment achieves a complete hermetic atomic cell structure by precisely etching a hole structure on the silicon wafer 1, bonding the silicon wafer 1 to the semiconductor glass layer using a bonding process, depositing a metal layer on the surface of the semiconductor glass layer, and fabricating a hollowed-out cross-shaped array structure on the metal layer to form a magnetic shielding layer. This structure effectively shields against external magnetic field interference, improves the stability of the MEMS atomic cell, and also has the advantage of facilitating integrated fabrication.

[0067] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A MEMS atomic gas chamber with a magnetic shielding layer, characterized in that, The device includes a silicon wafer with through-holes extending through its top and bottom ends. Transparent support layers are provided on both the top and bottom sides of the silicon wafer. A cavity is formed between the through-holes and the two transparent support layers. An alkali metal is placed in the cavity. A magnetic shielding layer is provided on the side of each transparent support layer away from the silicon wafer. The magnetic shielding layer is a substrate layer with a hollow cross-shaped array structure, and the hollow cross-shaped array structure corresponds to the position of the through-holes.

2. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 1, characterized in that, The two transparent support layers are respectively bonded to the upper and lower sides of the silicon wafer.

3. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 1, characterized in that, Each of the magnetic shielding layers is deposited on the side of the transparent support layer away from the silicon wafer.

4. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 1, characterized in that, The through hole is a cylindrical hole.

5. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 1, characterized in that, The transparent support layer is a semiconductor glass layer.

6. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 1, characterized in that, The substrate layer is made of metal.

7. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 6, characterized in that, The metal material is copper.

8. The MEMS atomic gas chamber with a magnetic shielding layer according to claim 1, characterized in that, The alkali metal is rubidium or cesium.

9. A method for fabricating a MEMS atomic gas cell with a magnetic shielding layer as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Process multiple through holes penetrating both the top and bottom ends on the silicon wafer; Step 2: Deposit the substrate layer on top of the transparent support layer, and place the transparent support layer on top of the silicon wafer to form an intermediate assembly; Step 3: Flip the intermediate assembly so that the transparent support layer is located below the silicon wafer, and place the alkali metal in each of the through holes; Step 4: Deposit the substrate layer on top of the other transparent support layer, and place the transparent support layer on top of the silicon wafer; Step 5: Process multiple hollow cross-shaped array structures in each of the substrate layers to form the magnetic shielding layer, such that each hollow cross-shaped array structure corresponds to one of the through holes to form an atomic gas chamber assembly; Step 6: Cut the atomic gas chamber assembly to prepare multiple MEMS atomic gas chambers.

10. The method for fabricating a MEMS atomic gas cell with a magnetic shielding layer according to claim 9, characterized in that, In step one, multiple vias are fabricated on the silicon wafer using photolithography and reactive ion etching.

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