Atomic beam collimator and method for manufacturing the same

Abstract

The present invention provides an atomic beam collimator and a manufacturing method thereof. The manufacturing method comprises: providing a silicon substrate, etching a first groove structure parallel to each other on a first surface in a thickness direction of the silicon substrate; providing a first supporting layer, anodically bonding the first supporting layer to the first surface in a thickness direction of the silicon substrate to form a stacked body; and cutting the stacked body to obtain an atomic beam collimator; wherein the first groove structure located between the silicon substrate and the first supporting layer serves as a first microchannel of the atomic beam collimator.

Description

Technical Field

[0001] The invention relates to the technical field of atomic beam collimators, in particular to an atomic beam collimator used in the fields of atomic beam fluorescence spectroscopy, atomic physics and precision measurement and a manufacturing method thereof. Background Art

[0002] Quantum frequency standards (such as atomic clocks) often use atomic beams sealed in a vacuum in physical components. Normally, the atomic beam escapes from a small hole at one end of a closed gas chamber. Since the hole is small enough, it will not destroy the gas balance in the gas chamber. In order to obtain an atomic beam with a small divergence angle and sufficient atomic beam current, a collimator with a densely packed porous structure is usually set at one end of the closed gas chamber. The collimator is used to confine atoms, reduce the free path of atoms, form a stable particle flow, and thus improve the utilization efficiency of the atomic beam.

[0003] At present, two-dimensional atomic beam collimators generally use technologies such as stacking capillaries made of materials such as quartz or tapering of capillary arrays to form a long and thin channel array, namely an atomic beam collimator. The above-mentioned method of making an atomic beam collimator made of capillaries has at least the following disadvantages: the capillaries are usually relatively thick, and the inner diameter is generally greater than 200μm (micrometers); when the capillaries are stacked to form a collimator array, there will be gaps between the capillaries in the collimator array; and when the capillary array is made by the capillary array taper process, the spacing between the capillaries is generally larger. However, for the collimator array structure, the parallelism between each capillary channel is difficult to ensure. For example, for a length of about 5mm (millimeter), the spacing difference is difficult to control to within 1μm (micrometer); for a single capillary channel, the diameter consistency (maximum and minimum diameter difference) of the single capillary itself is relatively poor. For capillaries with a length of about 5mm (millimeter), it is generally difficult to achieve a tolerance requirement of 1μm (micrometer).

[0004] The atomic beam collimator formed by the above-mentioned capillary stacking or capillary array tapering cannot arbitrarily control the size ratio of the capillary channel in the x and y directions. Therefore, the overall atomic beam ratio in the x and y directions can only be adjusted by increasing or decreasing the number of capillaries in a certain direction, which increases the process difficulty and size of device development.

[0005] In view of this, it is necessary to provide a new manufacturing process for an atomic beam collimator to overcome the problem of poor consistency of microchannels used to confine atoms in an atomic beam collimator formed by capillary stacking or capillary array taper. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a method for manufacturing an atomic beam collimator, the manufacturing method comprising: providing a silicon substrate, etching a first groove structure parallel to each other on a first surface in a thickness direction of the silicon substrate; providing a first supporting layer, anodically bonding the first supporting layer to the first surface in a thickness direction of the silicon substrate to form a stacked body; and cutting the stacked body to obtain an atomic beam collimator; wherein the first groove structure located between the silicon substrate and the first supporting layer serves as a first microchannel of the atomic beam collimator.

[0007] As an optional technical solution, second groove structures parallel to each other are etched on the second surface of the silicon substrate in the thickness direction, and the second surface is opposite to the first surface; a second supporting layer is provided, and the second supporting layer is anodically bonded to the second surface, and the stack includes the second supporting layer, the silicon substrate and the first supporting layer stacked in sequence; the stack is cut to obtain the atomic beam collimator; wherein the second groove structure located between the silicon substrate and the second supporting layer serves as a second microchannel of the atomic beam collimator.

[0008] As an optional technical solution, the first supporting layer and the second supporting layer are respectively a glass substrate or a silicon wafer substrate.

[0009] As an optional technical solution, the groove depths of the first groove structure and the second groove structure are respectively 20 μm (micrometer) to 300 μm (micrometer); the groove widths of the first groove structure and the second groove structure are respectively 30 μm (micrometer) to 200 μm (micrometer).

[0010] As an optional technical solution, a third groove structure parallel to each other is formed by etching the third surface exposed in the thickness direction of the first supporting layer; a third supporting layer is provided, and the third supporting layer is anodically bonded to the third surface, wherein the stack includes the silicon substrate, the first supporting layer and the third supporting layer stacked in sequence; the stack is cut to obtain the atomic beam collimator; wherein the third groove structure located between the second supporting layer and the third supporting layer serves as a third microchannel of the atomic beam collimator.

[0011] As an optional technical solution, the first supporting layer and the second supporting layer are respectively selected from a silicon substrate or a glass substrate.

[0012] As an optional technical solution, the groove depths corresponding to the first groove structure and the third groove structure are respectively 20μm (micrometer) to 300μm (micrometer); the groove widths corresponding to the first groove structure and the third groove structure are respectively 20μm (micrometer) to 200μm (micrometer).

[0013] As an optional technical solution, the first groove structure is manufactured by electron beam lithography technology combined with wet etching or dry etching technology; or, is manufactured by etching using focused ion beam technology.

[0014] As an optional technical solution, a plurality of the first groove structures in the mutually parallel first groove structures are arranged at equal intervals.

[0015] The present invention also provides an atomic beam collimator, which is obtained by adopting the manufacturing method as described above.

[0016] The present invention provides an atomic beam collimator and a method for manufacturing the same. A semiconductor etching process is used to etch a groove structure on a silicon substrate, an anodic bonding process is used to bond a support layer and a silicon substrate to form a stack, and finally the atomic beam collimator is obtained by cutting the stack. The bonding process is moved forward to before the cutting process, so that the device has better integrity, better edge consistency, better sealing performance, and high process efficiency. In addition, for a structure including multiple support layers in the stack, the etching process on the surface of the support layer is moved to after the bonding process, and etching is performed on the stack composed of the support layer and the silicon substrate, which can enhance the overall strength of the stack. When the etching process is completed using a contact photolithography process, the etching efficiency is high, the cost is low, and the etching consistency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The present invention provides a flowchart of a method for manufacturing an atomic beam collimator.

[0019] Figure 2 It is a schematic diagram of an atomic beam collimator stack provided in one embodiment of the present invention.

[0020] Figure 3 for Figure 2 Schematic diagram of the silicon substrate.

[0021] Figure 4 for Figure 2 Schematic cross-sectional view of the corresponding atomic beam collimator fabrication process.

[0022] Figure 5 It is a schematic diagram of an atomic beam collimator stack provided in another embodiment of the present invention.

[0023] Figure 6 It is a schematic diagram of an atomic beam collimator stack provided in yet another embodiment of the present invention.

[0024] Figure 7 for Figure 6 Schematic cross-sectional view of the corresponding atomic beam collimator fabrication process. DETAILED DESCRIPTION

[0025] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0026] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0027] Reference Figure 1 The present invention provides a method 1000 for manufacturing an atomic beam collimator, comprising:

[0028] Providing a silicon substrate, and etching a first surface of the silicon substrate in a thickness direction to form first trench structures parallel to each other;

[0029] Providing a first supporting layer, and anodically bonding the first supporting layer to a first surface in a thickness direction of the silicon substrate to form a stacked body; and

[0030] The stacked body is cut to obtain an atomic beam collimator.

[0031] The first groove structure between the silicon substrate and the first supporting layer serves as a first microchannel of the atomic beam collimator.

[0032] In the above-mentioned manufacturing method provided by the present invention, a groove structure is first etched on the surface of a silicon substrate; a support layer is anodically bonded on one side of the groove structure to form a stacked body; and then the stacked body is cut to obtain an atomic beam collimator; after the cutting process, the atomic beam collimator is moved to the bonding process, so that the obtained atomic beam collimator has better physical properties, better edge consistency, and high manufacturing process efficiency.

[0033] In one embodiment of the present invention, the manufacturing method further includes:

[0034] Etching a second surface in the thickness direction of the silicon substrate to form second groove structures parallel to each other, the second surface being opposite to the first surface;

[0035] Providing a second supporting layer, and anodically bonding the second supporting layer to the second surface, wherein the stacked body comprises the second supporting layer, the silicon substrate, and the first supporting layer stacked in sequence;

[0036] cutting the stack to obtain an atomic beam collimator;

[0037] The second groove structure located between the silicon substrate and the second supporting layer serves as a second microchannel of the atomic beam collimator.

[0038] In addition, in a preferred embodiment, each first groove structure corresponds to each second groove structure in a one-to-one correspondence in the thickness direction of the stacked body.

[0039] In this embodiment, the atomic beam collimator is, for example, a two-dimensional groove structure, corresponding to a first groove structure and a second groove structure arranged up and down on the silicon substrate, which are opposite to each other, wherein a process flow of etching, anodic bonding, re-etching, re-anodic bonding, and finally cutting is adopted; the anodic bonding support layer is used to provide support for the subsequent re-etching process, so that the re-etching process on the back of the silicon substrate has better stability and better etching accuracy, especially when using a contact lithography process, the difficulty of the existing lithography process will not be increased due to the thickness of the silicon substrate itself. In addition, the support layer and the silicon substrate are connected by anodic bonding, and no other connecting materials are introduced, which helps to increase the sealing performance between the various layers of the atomic beam collimator.

[0040] In addition, in this embodiment, the first supporting layer and the second supporting layer are glass substrates respectively; preferably, the groove depths corresponding to the first groove structure and the second groove structure are 20μm~300μm respectively; the groove widths corresponding to the first groove structure and the second groove structure are 30nm~200nm (30μm~200μm) respectively.

[0041] In one embodiment of the present invention, the manufacturing method further includes:

[0042] Etching the third surface exposed in the thickness direction of the first supporting layer to form third trench structures parallel to each other;

[0043] Providing a third supporting layer, and anodically bonding the third supporting layer to the third surface, wherein the stacked body comprises a silicon substrate, a first supporting layer, and a third supporting layer stacked in sequence;

[0044] cutting the stack to obtain an atomic beam collimator;

[0045] The third groove structure located between the first supporting layer and the third supporting layer serves as the third microchannel of the atomic beam collimator.

[0046] In addition, in a preferred embodiment, each first groove structure and each third groove structure correspond to each other in the thickness direction of the stacked body.

[0047] In this embodiment, the atomic beam collimator is, for example, a two-dimensional groove structure, including a first groove structure and a third groove structure arranged on different stacks, wherein a process flow of etching, anodic bonding, re-etching, re-anodic bonding, and finally cutting is adopted; the overall strength of the stack formed by anodic bonding is good, and at the same time, the stack also provides good sealing performance, and the re-etching process is carried out on the stack, so the etching stability and precision are high.

[0048] In addition, in this embodiment, the first supporting layer and the third supporting layer are respectively selected from a silicon substrate or a glass substrate, wherein the materials of the first supporting layer and the third supporting layer can be the same or different.

[0049] Furthermore, the groove depths corresponding to the first groove structure and the third groove structure are respectively 20 μm to 300 μm; and the groove widths corresponding to the first groove structure and the third groove structure are respectively 30 μm to 200 μm.

[0050] In the above implementation method, the groove width w (refer to Figure 4 ) is between 10μm and 300μm; it can also be between 20μm and 200μm; it can also be between 30μm and 150μm; it can also be between 40μm and 100μm. Preferably, the groove widths corresponding to the first groove structure, the second groove structure, and the third groove structure are between 30μm and 200μm.

[0051] As can be seen from the above, the method for manufacturing an atomic beam collimator provided by the present invention can enhance the overall strength of the stack including the silicon substrate and the support layer in the manufacture of an atomic beam collimator with a two-dimensional microchannel structure, regardless of whether the support layer is used as a support portion for the next etching or as an etching portion for the next etching. Considering the thickness requirements of the etching process itself for the etched material, the manufacturing method of the present invention performs etching on the stack composed of the support layer and the silicon substrate, which can significantly reduce the difficulty of other etching processes except the first etching process for the manufacture of an atomic beam collimator with a two-dimensional and multi-dimensional microchannel structure. In addition, the etching accuracy can also be higher.

[0052] In other words, the method for manufacturing the atomic beam collimator provided by the present invention has the following advantages:

[0053] 1) The size of the etched microchannel can be smaller. The microchannel is used to achieve a higher aspect ratio, which is conducive to achieving a better atomic beam collimation effect. The size ratio of the width and depth of the microchannel formed by the etching process is easier to control and has high control accuracy. It can ensure the collimation effect of one-dimensional atomic beam while expanding the atomic beam flow as needed;

[0054] 2) The dimensional tolerance of the microchannel itself and the dimensional tolerance between microchannels can be controlled more precisely, so that the crosstalk between the final atomic beams is lower;

[0055] 3) Etching first, then bonding, and finally cutting, so that the overall device size can be made smaller and the final physical system is smaller;

[0056] 4) Through anodic bonding technology, close bonding between silicon wafer and silicon wafer, silicon wafer and glass is achieved, and finally a consistent two-dimensional array structure is formed;

[0057] 5) The use of photolithography and anodic bonding technology can complete related operations on large-size wafers, and finally cut them into chip devices of different sizes according to needs, which is very conducive to mass production and has good product consistency.

[0058] The following will be combined Figures 2 to 7 Detailed description of the above Figure 1 The manufacturing process of the manufacturing method 1000 provided in the invention.

[0059] Reference Figures 2 to 4 , providing a silicon substrate 1, etching a first surface 1b in the thickness direction of the silicon substrate 1 to form first groove structures 1a parallel to each other; providing a first support layer 2, the first support layer 2 is anodically bonded to the first surface 1b; etching a third surface 2b exposed in the thickness direction of the first support layer 2 to form third groove structures 2a parallel to each other; providing a second support layer 4, the second support layer 4 is anodically bonded to the third surface 2b to form an atomic beam collimator stack 30; cutting the stack 30 to obtain the atomic beam collimator 10.

[0060] In this embodiment, the first groove structure 1a between the silicon substrate 1 and the first supporting layer 2 serves as the first microchannel of the atomic beam collimator 10 ; the third groove structure 2a between the first supporting layer 2 and the second supporting layer 4 serves as the third microchannel of the atomic beam collimator 10 .

[0061] The atomic beam collimator 10 is a two-dimensional micro-groove structure.

[0062] In this embodiment, the first support layer 2 is, for example, a silicon substrate or a silicon carbide substrate, and the second support layer 4 is, for example, a glass substrate. It is understandable that in different embodiments, according to the alignment requirements, other one or more layers of silicon substrates can be further anodically bonded on the first support layer 2, and the bonding and etching processes are performed in sequence to form multi-dimensional groove structure features. In addition, the thickness of the first support layer 2 can be controlled to control the spacing between the first groove structure 1a and the third groove structure 2a in the thickness direction, so as to realize an atomic beam collimator with different alignment capabilities.

[0063] Reference Figure 3 and Figure 4 , a plurality of first groove structures 1a and a plurality of third groove structures 2a are arranged at equal intervals, a plurality of mutually parallel first groove structures 1a have the same size, a plurality of mutually parallel third groove structures 2a have the same size, and a size of each first groove structure 1a is the same as a size of each third groove structure 2a, but this is not limited thereto. In other embodiments of the present invention, a plurality of mutually parallel first groove structures may be arranged at non-equal intervals; a plurality of first grooves have different sizes; and a plurality of mutually parallel third groove structures may be arranged at non-equal intervals; a plurality of third grooves have different sizes.

[0064] Reference Figure 4 In the thickness direction of the atomic beam collimator 10, each first groove structure 1a corresponds to each third groove structure 2a. It should be noted that, according to the actual collimation requirements, each first groove structure 1a and each third groove structure 2a may also be non-one-to-one corresponding structures, for example, each first groove structure 1a and each third groove structure 2a are mutually staggered.

[0065] Reference Figure 5 In another embodiment of the present invention, another atomic beam collimator stack 3 is provided, which is different from the atomic beam collimator stack 30 in that the atomic beam collimator stack 3 only includes a silicon substrate 1 and a first supporting layer 2 bonded to one side of the first groove structure 1a.

[0066] Reference Figure 6 to Figure 7 , provide a silicon substrate 1, and etch a first groove structure 1a parallel to each other on a first surface 1b in a thickness direction of the silicon substrate 1; provide a first support layer 5, and anodically bond the first support layer 5 to the first surface 1b; etch a second surface 1d in a thickness direction of the silicon substrate 1 to form a second groove structure 1c parallel to each other; provide a second support layer 6, and anodically bond the second support layer 6 to the second surface 1d to form a stack 40; cut the stack 40 to obtain an atomic beam collimator 100.

[0067] In this embodiment, the first groove structure 1a between the silicon substrate 1 and the first supporting layer 5 serves as the first microchannel of the atomic beam collimator 100; the second groove structure 1c between the silicon substrate 1 and the second supporting layer 6 serves as the second microchannel of the atomic beam collimator 100.

[0068] In this embodiment, each first groove structure 1a corresponds to each second groove structure 1c in the thickness direction of the stacked body 40. It can be understood that, according to the actual alignment requirements, each first groove structure 1a and each second groove structure 1c can also be a non-one-to-one corresponding structure, for example, each first groove structure 1a and each second groove structure 1c are arranged in a staggered manner.

[0069] In addition, the second trench structures 1c parallel to each other may be arranged at equal intervals or at non-equal intervals.

[0070] In this embodiment, the first supporting layer 5 and the second supporting layer 6 are respectively a glass substrate or a silicon wafer substrate.

[0071] In one embodiment of the present invention, the etching process used for etching the silicon substrate 1 and etching the first supporting layer 2 includes, but is not limited to, using electron beam lithography technology combined with wet etching or dry etching technology; or, using focused ion beam technology to etch.

[0072] The present invention also provides an atomic beam collimator, which is obtained by using the manufacturing method described in any of the above embodiments. The structure of the atomic beam collimator includes but is not limited to: Figure 4 Atomic beam collimator 10 or Figure 7 The atomic beam collimator 100 is shown in FIG.

[0073] In summary, the present invention provides an atomic beam collimator and a method for making the same, wherein a semiconductor etching process is used to etch a groove structure on a silicon substrate, an anodic bonding process is used to bond a support layer and a silicon substrate to form a stack, and finally the atomic beam collimator is obtained by cutting the stack, and the bonding process is moved forward to before the cutting process, so that the device has better integrity, better edge consistency, better sealing performance, and high process efficiency. In addition, for a structure in which a plurality of support layers are included in the stack, the etching process on the surface of the support layer is moved to after the bonding process, and etching is performed on the stack composed of the support layer and the silicon substrate, so that the overall strength of the stack can be enhanced. When the etching process is completed using a contact photolithography process, the etching efficiency is high, the cost is low, and the etching consistency is high.

[0074] The present invention has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present invention. In addition, the technical features involved in the different embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A method for manufacturing an atomic beam collimator, which is suitable for manufacturing an atomic beam collimator with a two-dimensional microchannel structure, characterized in that: The production method comprises: Providing a silicon substrate, and etching to form mutually parallel first trench structures on a first surface in a thickness direction of the silicon substrate; Providing a first supporting layer, and anodically bonding the first supporting layer to a first surface of the silicon substrate in a thickness direction to form a stacked body; and cutting the stack to obtain an atomic beam collimator; Wherein, the first groove structure located between the silicon substrate and the first supporting layer serves as a first microchannel of the atomic beam collimator; Forming the laminate further comprises: After anodic bonding, a second surface in the thickness direction of the silicon substrate is etched again to form a second groove structure parallel to each other, the second surface and the first surface are opposite to each other, then, a second supporting layer is provided, and the second supporting layer is anodic bonded to the second surface to form a stack, the stack includes the second supporting layer, the silicon substrate and the first supporting layer stacked in sequence, and the second groove structure located between the silicon substrate and the second supporting layer serves as the second microchannel of the atomic beam collimator; or, a third surface exposed in the thickness direction of the first supporting layer is etched again to form a third groove structure parallel to each other, a third supporting layer is provided, and the third supporting layer is anodic bonded to the third surface to form a stack, the stack includes the silicon substrate, the first supporting layer and the third supporting layer stacked in sequence, and the third groove structure located between the second supporting layer and the third supporting layer serves as the third microchannel of the atomic beam collimator.

2. The method according to claim 1, characterized in that: The first supporting layer and the second supporting layer are respectively a glass substrate or a silicon wafer substrate.

3. The method according to claim 1, characterized in that: The groove depths corresponding to the first groove structure and the second groove structure range from 20 micrometers to 300 micrometers respectively; the groove widths corresponding to the first groove structure and the second groove structure range from 30 micrometers to 200 micrometers respectively.

4. The method according to claim 1, characterized in that: The first supporting layer and the third supporting layer are respectively selected from a silicon substrate or a glass substrate.

5. The method according to claim 1, characterized in that: The groove depths corresponding to the first groove structure and the third groove structure range from 20 micrometers to 300 micrometers respectively; the groove widths corresponding to the first groove structure and the third groove structure range from 30 micrometers to 200 micrometers respectively.

6. The method according to claim 1, characterized in that: The first groove structure is manufactured by electron beam lithography technology combined with wet etching or dry etching technology; or, the first groove structure is manufactured by focused ion beam etching technology.

7. The manufacturing method according to claim 1, characterized in that: A plurality of the first groove structures in the mutually parallel first groove structures are arranged at equal intervals.

8. An atomic beam collimator, characterized in that: The atomic beam collimator is obtained by adopting the manufacturing method according to any one of claims 1 to 7.

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