Preparation method of helium ion detector

Abstract

According to the preparation method of the helium ion detector provided by the invention, ideal electric field distribution can be obtained by arranging the collecting electrode in the closed chamber, and the ion collecting efficiency can be effectively improved by arranging the bias electrode in the closed chamber, so that the helium ion detector can also have a lower detection limit on the premise of a smaller volume, and the detection cost is reduced. The detection sensitivity is relatively high. In addition, the helium ion detector adopts a sandwich structure and is suitable for being combined with a chromatographic column for use or being integrated with a micro-chromatographic column in a monolithic manner.

Description

[0001] This application is a divisional application of the patent with an application date of November 15, 2023, an application number of 202311526934.4, and an invention title of Helium Ion Detector and Its Preparation Method. Technical Field

[0002] The present invention belongs to the field of microelectromechanical systems and relates to a preparation method of a helium ion detector. Background Art

[0003] A gas chromatography system is a technical means for separating and detecting the components of a complex mixed gas, and its core components are a chromatographic column and a detector. Currently, the commonly used detectors in gas chromatography systems are flame ionization detectors and thermal conductivity detectors. Among them, the flame ionization detector has a simple structure and has a high response to almost all volatile and semi-volatile organic compounds, but it cannot detect water and permanent gases; the thermal conductivity detector responds to all gases except the carrier gas, but its sensitivity is low and it is very sensitive to changes in flow rate and temperature.

[0004] A helium ion detector is a general-purpose gas detector. Due to the high ionization energy of helium (19.8 eV), the helium ion detector can detect all gases except neon, and has a detection limit of ppb level, which can be well combined with the chromatographic column for trace gas detection.

[0005] In 1960, Berry first proposed a gas detection technology that uses helium as the carrier gas and ionizes the analyte by means of gas discharge. After that, researchers further studied this detection technology and found that the detection ability of the helium ion detector is related to the stability of the plasma and the number, structure, and position of the excitation electrode and the collection electrode. The increase in the chamber volume can obtain higher sensitivity and a larger linear detection range, and setting multiple pairs of bias / collection electrodes in the chamber can improve sensitivity, improve peak shape symmetry, and can use a lower helium flow rate without affecting peak tailing.

[0006] In recent years, with the development of MEMS technology, a micro helium ion detector has been proposed. However, due to the reduction in the device volume, the chamber volume decreases, and the smaller chamber volume will affect the sensitivity and detection limit of the micro helium ion detector. To solve the above problems, it is necessary to design and prepare a bias / collection electrode group structure with high collection efficiency to improve the sensitivity of the micro helium ion detector.

[0007] Therefore, it is necessary to provide a preparation method of a helium ion detector. Summary of the Invention

[0008] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a method for preparing a helium ion detector, which is used to solve the detection problems brought about by the miniaturization of the helium ion detector in the prior art.

[0009] To achieve the above purpose and other related purposes, the present invention provides a method for preparing a helium ion detector, including the following steps:

[0010] Provide a substrate;

[0011] Provide an upper cover plate and a lower cover plate, form a first collection electrode on the upper cover plate, form a second collection electrode on the lower cover plate, and first and second bias electrodes on both sides of the second collection electrode;

[0012] Pattern the substrate, form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode, and the second bias electrode;

[0013] Bond the lower cover plate to the lower surface of the substrate;

[0014] Bond the upper cover plate to the upper surface of the substrate, form a closed chamber by covering the through groove with the upper cover plate, form a closed input / output channel by covering the input / output through groove, and form an excitation electrode channel by covering the excitation electrode through groove, and the first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

[0015] The present invention also provides a method for preparing a helium ion detector, including the following steps:

[0016] Provide a substrate;

[0017] Provide an upper cover plate and a lower cover plate, form a first collection electrode on the upper cover plate, form a second collection electrode on the lower cover plate, and first and second bias electrodes on both sides of the second collection electrode;

[0018] Pattern the substrate, form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode, and the second bias electrode;

[0019] Bond the upper cover plate to the upper surface of the substrate;

[0020] Bond the lower cover plate to the lower surface of the substrate, and form a closed chamber by covering the through groove with the lower cover plate, form a closed input / output channel by covering the input / output through groove, and form an excitation electrode channel by covering the excitation electrode through groove, and the first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

[0021] Optionally, an electrode accommodating groove for accommodating the first collection electrode is formed on the upper surface of the substrate, and electrode accommodating grooves for respectively accommodating the second collection electrode, the first bias electrode, and the second bias electrode are formed on the lower surface of the substrate.

[0022] Optionally, it further includes a step of dicing.

[0023] Optionally, during dicing, back-and-forth dicing is respectively performed from the upper cover plate and the lower cover plate to expose the electrical connection ends of the first collection electrode, the second collection electrode, the first bias electrode, and the second bias electrode.

[0024] Optionally, the formed first bias electrode and second bias electrode are symmetrically arranged along the second collection electrode.

[0025] Optionally, the distances between the first bias electrode and the second bias electrode and the second collection electrode are both 300 μm to 1000 μm, the distance between adjacent bias electrodes and the excitation electrode is 500 μm to 2000 μm, and the distance between the first collection electrode and the second collection electrode is 200 μm to 700 μm.

[0026] Optionally, the substrate includes a silicon substrate, a ceramic substrate, or a glass substrate; the upper cover plate includes a silicon cover plate, a ceramic cover plate, or a glass cover plate; the lower cover plate includes a silicon cover plate, a ceramic cover plate, or a glass cover plate.

[0027] As described above, in the preparation method of the helium ion detector of the present invention, a pair of collection electrodes are arranged in the closed chamber to obtain a relatively ideal electric field distribution, and the combined arrangement of bias electrodes in the closed chamber can effectively improve the ion collection efficiency, so that the helium ion detector can also have a lower detection limit and higher detection sensitivity on the premise of a smaller volume. In addition, the helium ion detector adopts a sandwich structure and is suitable for being combined with a chromatographic column or monolithically integrated with a microchromatographic column. Description of the Drawings

[0028] Figure 1 It shows a process flow chart of the preparation of the helium ion detector in the present invention.

[0029] Figures 2a to 2f It shows a schematic structural diagram formed by each process step of the helium ion detector in the present invention.

[0030] Figure 3 Shown is a schematic three-dimensional structure diagram of the helium ion detector in the present invention.

[0031] Figure 4a Shown is a distribution diagram of the flow velocity field inside the helium ion detector in the present invention.

[0032] Figure 4b Shown is a curve of the flow velocity at the glow excitation of the helium ion detector in the present invention varying with the x coordinate.

[0033] Figure 5a Shown is a simulation distribution diagram of the electric field lines of the helium ion detector in the present invention for the collection electrode.

[0034] Figure 5b Shown is a simulation distribution diagram of the electric field lines of the helium ion detector in the present invention for the planar collection electrode.

[0035] Figure 5c Shown is a diagram of the variation of the electric field strength at the plate of the collection electrode of the helium ion detector in the present invention with the Y coordinate.

[0036] Figure 5d Shown is a diagram of the variation of the electric field strength at the plate of the planar collection electrode of the helium ion detector in the present invention with the Y coordinate.

[0037] Figure 6 Shown is a chromatogram elution curve of the helium ion detector in the present invention combined with a chromatographic column for C2-C4 testing.

[0038] Description of component labels

[0039] 100 Silicon substrate

[0040] 101 Top silicon oxide layer

[0041] 102 Bottom silicon oxide layer

[0042] 103 First collection electrode accommodation groove

[0043] 104 Second collection electrode accommodation groove

[0044] 105 First bias electrode accommodation groove

[0045] 106 Second bias electrode accommodation groove

[0046] 107 Through groove

[0047] 200 Upper glass cover plate

[0048] 201 First collection electrode

[0049] 300 Lower glass cover plate

[0050] 301 Second collection electrode

[0051] 302 First bias electrode

[0052] 303 Second bias electrode

[0053] 500 Closed chamber

[0054] 600 Sample input channel

[0055] 700 Carrier gas input channel

[0056] 800 Gas output channel

[0057] 900 Excitation electrode channel

[0058] 110 Excitation electrode Detailed implementation manners

[0059] The following illustrates the implementation manners of the present invention through specific specific examples. 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 implementation manners. 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.

[0060] When detailing the embodiments of the present invention, for the convenience of description, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the protection scope of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0061] For the convenience of description, spatial relationship terms such as "beneath", "below", "lower than", "under", "above", "on", etc. may be used here to describe the relationship between one element or feature shown in the drawings and other elements or features. It will be understood that these spatial relationship terms are intended to include other directions of the device in use or operation besides the directions depicted in the drawings. Embodiments where the first and second features are formed in direct contact may be included, and embodiments where additional features are formed between the first and second features may also be included, such that the first and second features may not be in direct contact. Additionally, when a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or there may be one or more intervening layers.

[0062] It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the illustrations, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0063] For example Figure 1 , this embodiment provides a method for preparing a helium ion detector, including the following steps:

[0064] S1: Provide a substrate;

[0065] S2: Provide an upper cover plate and a lower cover plate. Form a first collection electrode on the upper cover plate, and form a second collection electrode, a first bias electrode, and a second bias electrode on the lower cover plate, with the first and second bias electrodes located on both sides of the second collection electrode;

[0066] S3: Pattern the substrate to form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode, and the second bias electrode;

[0067] S4: Bond the lower cover plate to the lower surface of the substrate;

[0068] S5: Bond the upper cover plate to the upper surface of the substrate. Cover the through groove through the upper cover plate to form a closed chamber, cover the input / output through groove to form a closed input / output channel, and cover the excitation electrode through groove to form an excitation electrode channel, and the first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

[0069] The following will further introduce the preparation of the helium ion detector in conjunction with the attached Figures 2a to 2f and Figure 3 .

[0070] First, refer to Figure 1 , and perform step S1 to provide a substrate.

[0071] Specifically, refer to Figure 2a , the substrate may include a silicon substrate, a ceramic substrate, a glass substrate, etc. In this embodiment, the substrate uses a silicon substrate 100 that is relatively easy to perform MEMS processes, so as to facilitate the subsequent convenient integration preparation or combined application of the prepared helium ion detector with a chromatographic column, etc., but the type of the substrate is not limited thereto.

[0072] As an example, an electrode receiving groove for receiving the first collecting electrode may be formed on the upper surface of the substrate, and electrode receiving grooves for respectively receiving the second collecting electrode, the first bias electrode, and the second bias electrode are formed on the lower surface of the substrate, so as to ensure an airtight bonding between the substrate and the cover plate during the bonding process.

[0073] Specifically, referring to Figures 2a to 2c , in this embodiment, a first collecting electrode receiving groove 103 for receiving the first collecting electrode is formed on the upper surface of the silicon substrate 100, a second collecting electrode receiving groove 104 for receiving the second collecting electrode, a first bias electrode receiving groove 105 for receiving the first bias electrode, and a second bias electrode receiving groove 106 for receiving the second bias electrode are formed on the lower surface of the silicon substrate 100.

[0074] Among them, when preparing the first collecting electrode receiving groove 103, the second collecting electrode receiving groove 104, the first bias electrode receiving groove 105, and the second bias electrode receiving groove 106, a top silicon oxide layer 101 on the upper surface of the silicon substrate 100 and a bottom silicon oxide layer 102 on the lower surface of the silicon substrate 100 can be formed on the surface of the silicon substrate 100 by using a thermal oxidation process, such as Figure 2a ; then, the top silicon oxide layer 101 and the bottom silicon oxide layer 102 can be patterned in a BOE solution with a photoresist as a mask, and etched with a KOH solution or the like to pattern the silicon substrate 100 to form the required electrode receiving grooves, such as Figure 2b ; then, the excess photoresist, the top silicon oxide layer 101, and the bottom silicon oxide layer 102 are removed, such as Figure 2c .

[0075] The method for preparing the electrode receiving groove is not limited thereto. For example, dry etching or the like can also be used, and no excessive limitation is made here.

[0076] In another embodiment, if the collecting electrode and the bias electrode are embedded in the cover plate, so that no airtightness problem will be caused during the bonding of the cover plate and the substrate, then the electrode receiving groove may not be prepared on the substrate, but the corresponding electrode receiving groove is prepared in the cover plate, and specific selection can be made according to needs, and no excessive limitation is made here.

[0077] Next, referring to Figure 1 , perform step S2, provide an upper cover plate and a lower cover plate, form a first collecting electrode on the upper cover plate, and form a second collecting electrode, a first bias electrode, and a second bias electrode on both sides of the second collecting electrode on the lower cover plate.

[0078] As an example, the upper cover plate may include a silicon cover plate, a ceramic cover plate or a glass cover plate; the lower cover plate may include a silicon cover plate, a ceramic cover plate or a glass cover plate.

[0079] Specifically, referring to Figure 2d and Figure 2e , in this embodiment, both the upper cover plate and the lower cover plate are made of glass cover plates, but the materials of the upper cover plate and the lower cover plate are not limited thereto, and silicon cover plates, ceramic cover plates, etc. can also be used. In this embodiment, a patterned first collection electrode 201 is formed on the upper glass cover plate 200, and a second collection electrode 301, a first bias electrode 302 and a second bias electrode 303 are formed on the lower glass cover plate 300, and the first bias electrode 302 and the second bias electrode 303 are symmetrically arranged along the second collection electrode 301.

[0080] Among them, the preparation of the first collection electrode 201, the second collection electrode 301, the first bias electrode 302 and the second bias electrode 303 can be prepared by processes such as sputtering, etching and degluing, but it is not limited thereto. The material of the electrode can be Cr / Au, etc., which is not limited here.

[0081] Next, referring to Figure 1 , perform step S3 to pattern the substrate, and form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode and the second bias electrode.

[0082] Specifically, referring to Figure 2d , a deep reactive ion etching (DRIE) can be performed on the upper surface of the silicon substrate 100 with a photoresist as a mask to form a through groove 107 penetrating the silicon substrate 100, an input / output through groove (not shown) communicating with the through groove 107, and an excitation electrode through groove (not shown), and the through groove 107 exposes the second collection electrode 301, the first bias electrode 302 and the second bias electrode 303.

[0083] Next, referring to Figure 1 , perform step S4 to bond the lower cover plate to the lower surface of the substrate.

[0084] Specifically, referring to Figure 2d , since in this embodiment, the substrate uses the silicon substrate 100 and the lower cover plate uses the lower glass cover plate 300, thus, the method of bonding the lower cover plate to the lower surface of the substrate can use anodic bonding, but the bonding method is not limited thereto, and can be specifically selected according to the materials of the lower cover plate and the substrate.

[0085] Next, referring toFigure 1 Execute step S5 to bond the upper cover plate to the upper surface of the substrate. By covering the through groove with the upper cover plate, a closed chamber is formed, the input / output through groove is covered to form a closed input / output channel, and the excitation electrode through groove is covered to form an excitation electrode channel. The first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

[0086] Specifically, referring to Figure 2f , in this embodiment, since the substrate uses the silicon substrate 100 and the upper cover plate uses the upper glass cover plate 200, thus, the method of bonding the upper cover plate to the upper surface of the substrate can adopt the anodic bonding method, but the bonding method is not limited thereto, and can be specifically selected according to the materials of the upper cover plate and the substrate.

[0087] Among them, referring to Figure 3 , after the bonding process is completed, the through groove 107 forms a closed chamber 500, the input / output through groove forms a closed input / output channel, including a sample input channel 600, a carrier gas input channel 700, a gas output channel 800, and an excitation electrode channel 900 for accommodating the excitation electrode 110. The first collection electrode 201 is exposed in the closed chamber 500 and is correspondingly arranged with the second collection electrode 301 to form a pair of collection electrodes.

[0088] In this embodiment, by forming the pair of collection electrodes in the closed chamber 500, a relatively ideal electric field distribution can be obtained, and by combining and arranging the first bias electrode 302 and the second bias electrode 303 in the closed chamber 500, the ion collection efficiency can be effectively improved, so that the helium ion detector can also have a low detection limit and high detection sensitivity under the premise of a small volume; and since the helium ion detector adopts a sandwich structure, it is suitable for being combined with a chromatographic column or monolithic integration.

[0089] In another embodiment, the upper cover plate can also be first bonded to the upper surface of the substrate, and then the lower cover plate is bonded to the lower surface of the substrate. That is, the preparation method of the helium ion detector may further include:

[0090] S1’: Provide a substrate;

[0091] S2’: Provide an upper cover plate and a lower cover plate, form a first collection electrode on the upper cover plate, form a second collection electrode and a first bias electrode and a second bias electrode on both sides of the second collection electrode on the lower cover plate;

[0092] S3’: Pattern the substrate to form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode, and the second bias electrode;

[0093] S4’: Bond the upper cover plate to the upper surface of the substrate;

[0094] S5’: Bond the lower cover plate to the lower surface of the substrate. The through groove is covered by the lower cover plate to form a closed chamber, the input / output through groove is covered to form a closed input / output channel, and the excitation electrode through groove is covered to form an excitation electrode channel. The first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

[0095] For the specific preparation and operations of steps S1’ to S5’, reference can be made to the above steps S1 to S5. Only the sequence of steps S4 and S5 needs to be replaced, and details are not elaborated here.

[0096] As an example, it may further include a dicing step. During dicing, reverse dicing is performed from the upper cover plate and the lower cover plate respectively to expose the electrical connection ends of the first collection electrode, the second collection electrode, the first bias electrode, and the second bias electrode.

[0097] Specifically, after the bonding is completed, through the dicing process step, a helium ion detector that meets the size requirements can be obtained. Among them, the overall size of the prepared helium ion detector can be 19.3 mm × 9.96 mm × 1.45 mm, the size of the closed chamber 500 can be 8.2 mm × 5 mm × 0.45 mm, and the width of the input / output channel port can be 400 μm. The specific size of the helium ion detector can be selected according to needs.

[0098] Refer to Figure 3 , in this embodiment, during dicing, it is preferably to perform reverse dicing from the upper glass cover plate 200 and the lower glass cover plate 300 respectively to cut and form Figure 3 the zigzag shape in

[0099] Further, it may also include steps of installing capillaries (not shown) in the sample input channel 600, the carrier gas input channel 700, and the gas output channel 800, and performing epoxy resin pipe sealing, and inserting the excitation electrode 110 into the excitation electrode channel 900, so as to connect the helium ion detector to the chromatographic column and perform corresponding detection.

[0100] As an example, the formed first bias electrode 302 and the second bias electrode 303 are symmetrically arranged along the second collection electrode 301, and the distance between the first bias electrode 302 and the second bias electrode 303 and the second collection electrode 301 may be 300 μm to 1000 μm, such as 300 μm, 500 μm, 600 μm, 800 μm, 1000 μm, etc. The distance between the adjacent second bias electrode 303 and the excitation electrode 110 may be 500 μm to 2000 μm, such as 500 μm, 1000 μm, 1500 μm, 2000 μm, etc. The distance between the first collection electrode 201 and the second collection electrode 301 may be 200 μm to 700 μm, such as 200 μm, 450 μm, 600 μm, 700 μm, etc. Regarding the specific settings of the first collection electrode 201, the second collection electrode 301, the first bias electrode 302, and the second bias electrode 303, selection can be made according to needs.

[0101] Refer to Figures 2a to 2f and Figure 3 In addition, this embodiment also provides a helium ion detector. The helium ion detector can be directly prepared by the above preparation process but is not limited thereto. Of course, it can also be obtained by other preparation processes.

[0102] In this embodiment, the helium ion detector is directly prepared by the above process. Therefore, the materials, preparation process, structure, etc. of the helium ion detector are not elaborated here.

[0103] Specifically, the helium ion detector includes a sandwich structure composed of an upper cover plate, a lower cover plate, and a patterned substrate. Among them, a first collection electrode 201 is provided on the upper cover plate, i.e., the upper glass cover plate 200; a second collection electrode 301, a first bias electrode 302, and a second bias electrode 303 are provided on the lower cover plate, i.e., the lower glass cover plate 300, with the first bias electrode 302 and the second bias electrode 303 located on both sides of the second collection electrode 301; through grooves 107 penetrating the silicon substrate 100, input / output through grooves (not shown) communicating with the through grooves 107, and excitation electrode through grooves (not shown) are provided in the substrate, i.e., the silicon substrate 100. The upper surface of the silicon substrate 100 is bonded to the upper glass cover plate 200, and the lower surface of the silicon substrate 100 is bonded to the lower glass cover plate 300. The through grooves 107 are covered by the upper glass cover plate 200 and the lower glass cover plate 300 to form a closed chamber 500, the input / output through grooves are covered to form a closed input / output channel including a sample input channel 600, a carrier gas input channel 700, a gas output channel 800, and the excitation electrode through grooves are covered to form an excitation electrode channel 900. The first collection electrode 201, the second collection electrode 301, the first bias electrode 302, and the second bias electrode 303 are exposed in the closed chamber 500, and the first collection electrode 201 and the second collection electrode 301 are correspondingly arranged to form a pair of collection electrodes.

[0104] The detection performance of the helium ion detector in this embodiment is tested as follows. Among them, the excitation voltage can be 100V - 600V. The first collection electrode 201 is electrically connected to the signal collection module, and the second collection electrode 301, the first bias electrode 302, and the second bias electrode 303 provide a positive bias voltage for the test.

[0105] Refer to Figure 4a It shows the flow velocity field distribution diagram inside the helium ion detector in this embodiment. Figure 4b It shows the curve of the flow velocity of the helium ion detector in this embodiment at the glow excitation point changing with the x coordinate. From Figure 4b It can be seen that the flow velocity field in the helium ion discharge area is stable, the flow velocity is small, a stable plasma group can be obtained, and the flow velocity is stable. Therefore, the plasma group jitters less, and lower noise can be obtained.

[0106] Refer to Figure 5a It shows the simulation distribution diagram of the electric field lines of the helium ion detector in this embodiment using a pair of collection electrodes. Figure 5b It shows the simulation distribution diagram of the electric field lines of the helium ion detector in this embodiment using a planar collection electrode. Figure 5c It shows the graph of the electric field intensity at the plate of the helium ion detector in this embodiment using a pair of collection electrodes changing with the Y coordinate. Figure 5dShown is the graph of the electric field strength varying with the Y coordinate at the planar collection electrode plate of the helium ion detector in this embodiment. From Figure 5c and Figure 5d it can be seen that from the electric field strength above the collection electrode plate, the electric field strength inside the collection electrode is about 5 times that of the planar collection electrode. Combining with the bias electrode, the collection electrode structure has a more ideal electric field line distribution and a higher ion collection efficiency.

[0107] Referring to Figure 6 , shown is the chromatogram effluent curve of the C2-C4 test with the helium ion detector in this embodiment combined with a chromatographic column. Among them, a 1 ppm C2-C4 alkane mixture is used to test the sensitivity of the helium ion detector with high sensitivity to the collection electrode. It can be seen that the helium ion detector has a high sensitivity to 1 ppm C2-C4, and the signal-to-noise ratio can reach 13.

[0108] In summary, for the preparation method of the helium ion detector of the present invention, setting the collection electrode in the closed chamber can obtain a relatively ideal electric field distribution, and combining and setting the bias electrode in the closed chamber can effectively improve the ion collection efficiency, so that the helium ion detector can also have a low detection limit and high detection sensitivity on the premise of a small volume. In addition, the helium ion detector adopts a sandwich structure and is suitable for being combined with a chromatographic column or monolithically integrated with a microchromatographic column.

[0109] The above embodiments merely illustrate the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a helium ion detector, characterized in that, it comprises the following steps: Provide a substrate; Provide an upper cover plate and a lower cover plate, form a first collection electrode on the upper cover plate, form a second collection electrode on the lower cover plate, and a first bias electrode and a second bias electrode on both sides of the second collection electrode; Pattern the substrate to form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode and the second bias electrode; Bond the lower cover plate to the lower surface of the substrate; Bond the upper cover plate to the upper surface of the substrate, cover the through groove through the upper cover plate to form a closed chamber, cover the input / output through groove to form a closed input / output channel, and cover the excitation electrode through groove to form an excitation electrode channel, and the first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

2. A method for preparing a helium ion detector, characterized in that, it comprises the following steps: Provide a substrate; Provide an upper cover plate and a lower cover plate, form a first collection electrode on the upper cover plate, form a second collection electrode on the lower cover plate, and a first bias electrode and a second bias electrode on both sides of the second collection electrode; Pattern the substrate to form a through groove penetrating the substrate, an input / output through groove communicating with the through groove, and an excitation electrode through groove in the substrate, and the through groove exposes the second collection electrode, the first bias electrode and the second bias electrode; Bond the upper cover plate to the upper surface of the substrate; Bond the lower cover plate to the lower surface of the substrate, cover the through groove through the lower cover plate to form a closed chamber, cover the input / output through groove to form a closed input / output channel, and cover the excitation electrode through groove to form an excitation electrode channel, and the first collection electrode is exposed in the closed chamber and is correspondingly arranged with the second collection electrode to form a pair of collection electrodes.

3. The method for preparing a helium ion detector according to claim 1 or 2, characterized in that: An electrode accommodation groove for accommodating the first collection electrode is formed on the upper surface of the substrate, and electrode accommodation grooves for respectively accommodating the second collection electrode, the first bias electrode and the second bias electrode are formed on the lower surface of the substrate.

4. The method for preparing a helium ion detector according to claim 1 or 2, characterized in that: It further comprises a step of dicing.

5. The method for preparing a helium ion detector according to claim 4, characterized in that: During dicing, perform front and back dicing respectively from the upper cover plate and the lower cover plate to expose the electrical connection ends of the first collection electrode, the second collection electrode, the first bias electrode and the second bias electrode.

6. The method for preparing a helium ion detector according to claim 1 or 2, characterized in that: The formed first bias electrode and second bias electrode are symmetrically arranged along the second collection electrode.

7. The method for preparing a helium ion detector according to claim 6, It is characterized in that: The distances between the first bias electrode and the second bias electrode and the second collection electrode are both 300 μm to 1000 μm, the distance between adjacent bias electrodes and excitation electrodes is 500 μm to 2000 μm, and the distance between the first collection electrode and the second collection electrode is 200 μm to 700 μm.

8. The method for preparing a helium ion detector according to claim 1 or 2, It is characterized in that: The substrate includes a silicon substrate, a ceramic substrate or a glass substrate; the upper cover plate includes a silicon cover plate, a ceramic cover plate or a glass cover plate; the lower cover plate includes a silicon cover plate, a ceramic cover plate or a glass cover plate.

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