A magnetic field device and method for regulating deep sputtering of glow discharge mass spectrometry

Abstract

The present invention discloses a magnetic field device and method for regulating deep sputtering of glow discharge mass spectrometry. The device includes: a housing having a hollow structure; a cover adapted to cover the opening of the housing, with a limiting portion provided on a side of the cover away from the housing; an insulating plate adapted to be installed in the housing, the insulating plate being provided with a first through hole and six second through holes along the height direction, the six second through holes evenly surrounding the first through hole, a first spherical magnet adapted to be installed in the first through hole, and a second spherical magnet adapted to be installed in each of the second through holes; the magnetic poles of the six second spherical magnets are in the same direction and are all parallel to the insulating plate along the height direction, and the magnetic pole direction of the first spherical magnet is opposite to the magnetic pole direction of the second spherical magnet. In the present invention, the problem of uneven sputtering crater shape can be effectively improved, and the depth resolution is improved on the basis of improving signal strength.

Description

Technical Field

[0001] This invention relates to the field of inorganic mass spectrometry analysis technology, and further to a magnetic field device and method for controlling glow discharge mass spectrometry depth sputtering. Background Art

[0002] In recent years, the rapid development of advanced materials has placed increasingly higher demands on material characterization techniques and methods. For the composition of materials, the concentration and depth distribution of trace or ultra-trace elements have a significant impact on material properties such as optical, electrical, acoustic, and mechanical properties. Developing efficient characterization devices and methods to accurately characterize the concentration and depth distribution of trace or ultra-trace elements is not only helpful in revealing material properties, preparation processes, and mechanisms, but also crucial for optimizing material properties and designing and preparing higher-performance materials.

[0003] Glow discharge mass spectrometry (GDSMS) offers advantages such as direct analysis of solid materials, high resolution, low detection limits, wide linear dynamic range, simultaneous analysis of major, trace, and ultra-trace elements, and minimal matrix effects. It has become an indispensable characterization and research tool in materials development and production. In in-depth materials analysis, GDSMS provides concentration and depth distribution information for major, trace, and ultra-trace elements, offering an effective means to reveal diffusion, segregation, and performance prediction processes.

[0004] During glow discharge mass spectrometry depth analysis, sputtering pits generated on the sample surface generally have a morphological feature of deep edges and shallow middle, that is, there is unevenness at the bottom of the sputtering pits to varying degrees. The non-uniform sputtering nature reflected by this affects the resolution and accuracy of glow discharge mass spectrometry depth analysis.

[0005] Therefore, it is necessary to design a magnetic field device and method for controlling the depth sputtering of glow discharge mass spectrometry to solve the above problems. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a magnetic field device and method for controlling the depth sputtering of glow discharge mass spectrometry, which can effectively improve the problem of uneven sputtering pit shape and improve depth resolution while increasing signal strength.

[0007] To achieve the above objectives, the present invention provides a magnetic field device for controlling glow discharge mass spectrometry depth sputtering, comprising:

[0008] A housing, the housing being conductive, the housing having a hollow structure and an opening at one end;

[0009] A cover body, the cover body being conductive, the cover body being adapted to cover the opening of the housing, and a limiting part being provided on the side of the cover body away from the housing, the limiting part being used to limit the sample;

[0010] An insulating plate is adapted to be installed inside the housing. The insulating plate has a first through hole and six second through holes along the height direction. The six second through holes are evenly arranged around the first through hole. A first spherical magnet is adapted to be installed in the first through hole. The diameter of the first spherical magnet is smaller than the depth of the first through hole. A second spherical magnet is adapted to be installed in each second through hole. The diameter of the second spherical magnet is smaller than the depth of the second through hole.

[0011] The magnetic poles of the six second spherical magnets are in the same direction and are all parallel to the insulating plate along the height direction. The magnetic poles of the first spherical magnets are in the opposite direction to the magnetic poles of the second spherical magnets.

[0012] In some embodiments, both the housing and the cover are made of copper, and both the housing and the insulating plate are cylindrical structures.

[0013] In some embodiments, the limiting part includes a plurality of protrusions, which surround to form a receiving space adapted to the outer contour of the sample. The sample is fitted into the receiving space, such that the plurality of protrusions limit the sample.

[0014] In some embodiments, four protrusions are provided, all of which are square structures, and the four protrusions form a square receiving space. The four protrusions are equidistant from the center of the top of the cover.

[0015] In some embodiments, the insulating plate is a polytetrafluoroethylene plate, and the diameter of the first through hole is smaller than the diameter of the first spherical magnet, so that the first spherical magnet and the first through hole are in an interference fit.

[0016] The diameter of the second through hole is smaller than the diameter of the second spherical magnet, so that the second spherical magnet and the second through hole are in an interference fit.

[0017] In some embodiments, the insulating plate is detachably installed inside the housing, and multiple insulating plates are provided. The distance between two adjacent second through holes on the multiple insulating plates is different, so that when the second spherical magnet is installed on different insulating plates, the distance between the second spherical magnets is different.

[0018] In some embodiments, both the first spherical magnet and the second spherical magnet are sintered NdFeB spherical magnets, the six second spherical magnets are of the same model, and the first spherical magnet and the second spherical magnet may be of the same or different model.

[0019] In some implementations, it also includes:

[0020] The first outer shell is conductive and has a hollow structure with an opening at one end. A tantalum sheet, a first insulating ceramic sheet, and a second insulating ceramic sheet are sequentially disposed inside the first outer shell.

[0021] The second outer shell is made of insulating material. One end of the second outer shell is inserted into the first outer shell and threadedly connected to the first outer shell, so that the second outer shell clamps and fixes the tantalum sheet, the first insulating ceramic sheet and the second insulating ceramic sheet between the bottom of the first outer shell and the end of the second outer shell.

[0022] The third outer shell is made of insulating material and is detachably connected to the end of the second outer shell away from the first outer shell. An elastic element is provided inside the third outer shell, and a sample inlet rod is connected to the end of the third outer shell away from the second outer shell.

[0023] The sample, the cover, the insulating plate, and the housing are assembled into one unit and installed inside the second outer shell. This overall structure is supported on the second insulating ceramic sheet by the elastic element. The sample is located on the side closer to the second insulating ceramic sheet, and the housing is located on the side closer to the elastic element.

[0024] According to another aspect of the present invention, the present invention further provides a method for using a magnetic field device for controlling glow discharge mass spectrometry depth sputtering as described in any one of the above, comprising the steps of:

[0025] A first spherical magnet is installed in the first through hole, and six second spherical magnets are installed in the corresponding second through holes. The magnetic poles of the six second spherical magnets are in the same direction and are all parallel to the height of the insulating plate. The magnetic poles of the first spherical magnet are opposite to the magnetic poles of the second spherical magnets.

[0026] An insulating plate with the first spherical magnet and the second spherical magnet fixed on it is placed into the housing, and then the cover is fitted and placed over the opening of the housing.

[0027] The sample is placed in the middle of the side of the cover away from the shell, so that the limiting part limits the sample and prevents the sample from shifting during filling, injection and analysis.

[0028] In some implementations, the steps also include:

[0029] A tantalum sheet, a first insulating ceramic sheet, and a second insulating ceramic sheet are sequentially placed inside a first outer shell. One end of a second outer shell is inserted into the first outer shell and threadedly connected to the first outer shell, such that the second outer shell clamps and fixes the tantalum sheet, the first insulating ceramic sheet, and the second insulating ceramic sheet between the bottom of the first outer shell and the end of the second outer shell.

[0030] The assembled housing is placed inside the second housing, and the third housing is threaded to the end of the second housing away from the first housing, so that the whole structure is held on the second insulating ceramic sheet by an elastic element, wherein the sample is located on the side closer to the second insulating ceramic sheet, and the housing is located on the side closer to the elastic element;

[0031] The injection rod is threaded to the third outer shell, and the assembled structure of the first outer shell, the second outer shell, and the third outer shell is pushed into the glow discharge mass spectrometer cell through the injection rod.

[0032] Compared with the prior art, the magnetic field device and method for controlling glow discharge mass spectrometry depth sputtering provided by the present invention have the following advantages:

[0033] In this invention, by setting a limiting part on the cover, the sample can be effectively confined to the center position of the cover, avoiding the phenomenon of uneven sputtering caused by sample displacement during sample preparation. By using insulating plates with different through-hole spacings, the distance between the second spherical magnets is indirectly adjusted, that is, different spacings can be selected in combination with the discharge aperture. The horizontal component of the magnetic flux density is concentrated in the central region, which can bind some electrons in this region. The electron trajectory in this region is bent, and the collision frequency with neutral particles, especially argon atoms, increases, causing more argon atoms to ionize and increasing the number density of argon ions. The increase in the number density of argon ions can increase the sputtering flux in this region. The sputtering flux obtained by the magnetic field enhancement is used to balance the local high sputtering flux caused by the electric field effect at the sample edge, realizing layer-by-layer sputtering and obtaining a sputtering pit with a flat bottom, thereby obtaining excellent signal intensity and depth resolution. Attached Figure Description

[0034] The preferred embodiments will now be described in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of the present invention.

[0035] Figure 1 This is a schematic diagram of the structure of the magnetic field device for controlling the depth sputtering of glow discharge mass spectrometry according to a preferred embodiment of the present invention;

[0036] Figure 2This is a schematic diagram of the structure of the cover body according to a preferred embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of the insulating plate according to a preferred embodiment of the present invention;

[0038] Figure 4 This is a sputtering crater morphology image obtained by glow discharge mass spectrometry analysis of an aluminum sheet under non-magnetic field control according to a preferred embodiment of the present invention.

[0039] Figure 5 This is a sputtering crater morphology image obtained by glow discharge mass spectrometry analysis of an aluminum sheet under magnetic field control, according to a preferred embodiment of the present invention.

[0040] Figure 6 These are comparative examples and examples of the preferred embodiments of the present invention, showing the signal strength of aluminum obtained in the embodiments.

[0041] Explanation of icon numbers:

[0042] 1. Shell 2. Cover 3. Insulating plate 4. First spherical magnet 5. Second spherical magnet 6. Boss 7. Sample 8. First outer shell 9. Tantalum sheet 10. First insulating ceramic sheet 11. Second insulating ceramic sheet 12. Second outer shell 13. Third outer shell 14. Elastic element 15. Sample inlet rod 16. Detailed Implementation

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0044] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0045] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0046] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0048] In one embodiment, refer to the appendix to the specification. Figures 1 to 3 The present invention provides a magnetic field device for controlling depth sputtering of glow discharge mass spectrometry, comprising: a shell 1, a cover 2, and an insulating plate 3. The shell 1 is conductive and has a hollow structure with an opening at one end. The cover 2 is conductive and is fitted onto the opening of the shell 1. A limiting part is provided on the side of the cover 2 away from the shell 1 to limit the sample 7. The insulating plate 3 is fitted into the shell 1 and has a first through hole and six second through holes along its height. The six second through holes are evenly surrounding the first through hole. A first spherical magnet 4 is fitted into the first through hole, the diameter of which is smaller than the depth of the first through hole. A second spherical magnet 5 is fitted into each second through hole, the diameter of which is smaller than the depth of the second through hole. The six second spherical magnets 5 have the same magnetic pole orientation and are all parallel to the insulating plate 3 along the height direction. The magnetic pole orientation of the first spherical magnet 4 is opposite to that of the second spherical magnets 5. By employing a ring magnet array, the performance of the glow discharge mass spectrometer for material analysis is improved. Its structure is simple and reasonable, can effectively control the morphology of sputtering craters, and enhances signal intensity, making it suitable for glow discharge mass spectrometers or similar devices.

[0049] Specifically, refer to the instruction manual appendix. Figure 1 The shell 1 and the cover 2 are made of metal or alloy material, preferably copper. The shell 1 and the insulating plate 3 are cylindrical, square, or other shapes, preferably cylindrical. The opening of the shell 1 is located at the left end of the shell. The shell 1 and the cover 2 are connected by snaps or threads. The specific dimensions of the shell 1 and the cover 2 can be set according to actual needs. For example, the shell 1 has a thickness of 1.00 mm, an outer diameter of 35.00 mm, and a height of 7.00 mm; the cover 2 has a thickness of 1.00 mm, an outer diameter of 35.00 mm, and a height of 3.00 mm.

[0050] Insulating board 3 is a polytetrafluoroethylene board, and the height direction of insulating board 3 refers to... Figure 1The left-right direction is the thickness direction of the insulating plate 3. If the insulating plate 3 is a cylinder, the center of the first through hole coincides with the center of the cylinder, and the six second through holes are evenly distributed around the first through hole, that is, the centers of the six second through holes are distributed on the six vertices of a regular hexagon centered on the first through hole. For example, the height of the insulating plate 3 is 5.00 mm and the diameter is 30.50 mm. The diameter of both the first and second through holes is 4.70 mm, and the distance between the centers of two adjacent second through holes is 5.20 mm, 5.70 mm, 6.20 mm, and 6.70 mm, respectively. Other reasonable sizes can also be used, such as 5.30 mm, 5.40 mm, 5.50 mm, 5.60 mm, 5.80 mm, 5.90 mm, etc.

[0051] The first spherical magnet 4 and the second spherical magnet 5 are both sintered NdFeB spherical magnets, and their models can be sintered NdFeB N35, N42, N45, etc. The six second spherical magnets 5 have the same model, and the first spherical magnet 4 and the second spherical magnet 5 may have the same or different models.

[0052] Furthermore, the diameter of the first through hole is smaller than the diameter of the first spherical magnet 4, resulting in an interference fit between the first spherical magnet 4 and the first through hole; the diameter of the second through hole is smaller than the diameter of the second spherical magnet 5, resulting in an interference fit between the second spherical magnet 5 and the second through hole. The diameter of the spherical magnet is slightly larger than the corresponding through hole diameter. If the through hole diameter is 4.70 mm, then the diameter of the spherical magnet can be set to 4.76 mm. Since the PTFE sheet has a certain degree of elasticity, the interference fit allows for easy installation and removal of the spherical magnet within the corresponding through hole.

[0053] The limiting part includes several protrusions 6, which surround and form a receiving space that matches the outer contour of the sample. The sample 7 is fitted into the receiving space, so that the protrusions 6 limit the sample 7. For example, if there are four protrusions 6, all of which are square structures, the bottoms of the four protrusions 6 are fixed to the cover 2 to form a square receiving space. The four protrusions 6 are located on the side of the cover 2 away from the shell 1, and the distances of the four protrusions 6 from the center of the top circle of the cover 2 are equal. For example, if the distance of the four protrusions 6 from the center of the top circle of the cover 2 is 11.00 mm, the dimensions of the four protrusions 6 are 1.00 mm × 1.00 mm × 0.50 mm, the bottom surface of the sample 7 is square, the size is 20.00 × 20.00 mm, and the height is not less than 0.50 mm.

[0054] The insulating plate 3 is detachably installed inside the housing 1. Multiple insulating plates 3 are provided, and the distance between two adjacent second through holes on multiple insulating plates 3 is different, so that the distance between the second spherical magnets 5 is different when the second spherical magnets 5 are installed on different insulating plates 3.

[0055] In this embodiment, a magnetic field design is used to enhance sputtering in the central region of the sputtering crater in glow discharge mass spectrometry depth analysis, correcting sputtering inhomogeneity caused by edge electric field effects. The magnetic field control device includes a housing 1, a cover 2, an insulating plate 3, and a spherical magnet array. The top of the cover 2 has four small copper cuboid protrusions 6 evenly distributed from the center. The cylindrical polytetrafluoroethylene insulating plate 3 has seven centrally symmetrical through holes, each containing seven sintered NdFeB spherical magnets with their magnetic poles perpendicular to the height of the through holes. The magnetic poles of the central magnet are opposite to those of the surrounding magnets. The distance between the centers of the through holes can be set to 5.20 mm, 5.70 mm, 6.20 mm, and 6.70 mm. The combination of the housing 1, cover 2, insulating plate 3, and spherical magnet array can control sputtering and optimize the shape of the sputtering crater, ultimately improving the depth resolution and accuracy of glow discharge depth analysis.

[0056] In one embodiment, refer to the appendix to the specification. Figure 1 The magnetic field device for controlling glow discharge mass spectrometry depth sputtering provided by the present invention further includes: a first outer shell 8, a second outer shell 12, and a third outer shell 13. The first outer shell 8 is conductive and has a hollow structure with an opening at one end. A tantalum sheet 9, a first insulating ceramic sheet 10, and a second insulating ceramic sheet 11 are sequentially disposed inside the first outer shell 8. Both the first insulating ceramic sheet 10 and the second insulating ceramic sheet 11 have holes, with the hole diameter of the first insulating ceramic sheet 10 being larger than that of the second insulating ceramic sheet 11. The second outer shell 12 is made of insulating material, and one end of the second outer shell 12 is inserted into the first outer shell 8 and threadedly connected to the first outer shell 8, such that the second outer shell 12 clamps and fixes the tantalum sheet 9, the first insulating ceramic sheet 10, and the second insulating ceramic sheet 11 between the bottom of the first outer shell 8 and the end of the second outer shell 12. The third outer shell 13 is made of insulating material. The end of the third outer shell 13 away from the first outer shell 8 is detachably connected to the second outer shell 12. An elastic element 14, which can be a metal spring, is installed inside the third outer shell 13. A sample inlet rod 15 is connected to the end of the third outer shell 13 away from the second outer shell 12, and the sample inlet rod 15 is threadedly connected to the third outer shell 13. The sample 7, cover 2, insulating plate 3, and shell 1 are assembled into a single unit and installed inside the second outer shell 12. This overall structure is supported on the second insulating ceramic sheet 11 by the elastic element 14. The sample 7 is located on the side closer to the second insulating ceramic sheet 11, and the shell 1 is located on the side closer to the elastic element 14. The entire device is pushed into the glow discharge mass spectrometer cell using the sample inlet rod 15, and the sample loading is complete.

[0057] A device with a specific spherical magnet array is used to control the depth sputtering of glow discharge mass spectrometry. By applying a magnetic field with a specific spatial distribution to the ion source portion of the glow discharge mass spectrometer, the plasma density is locally increased, thereby enhancing sputtering in a localized area. Furthermore, by changing the structural parameters of the device to adapt to different discharge conditions and analytical samples, a flatter sputtering pit is obtained, achieving a layer-by-layer sputtering stripping effect. Ultimately, this improves the depth resolution and accuracy of glow discharge mass spectrometry depth analysis.

[0058] By adding an additional small cuboid protrusion 6 to the top of the cover 2, the sample 7 can be effectively fixed in the center of the cover 2, avoiding uneven sputtering caused by sample displacement during sample preparation. By using different through-hole spacings, the distance between the spherical magnets is indirectly adjusted, meaning different spacings can be selected in conjunction with the discharge aperture, such as 7.5mm, 10.0mm, 12.5mm, and 15mm. The horizontal component of the magnetic flux density is concentrated in the central region, which can confine some electrons within this region. The electron trajectory in this region is bent, increasing the collision frequency with neutral particles, especially argon atoms, promoting the ionization of more argon atoms and increasing the argon ion number density. The increased argon ion number density can increase the sputtering flux in this region. The sputtering flux obtained by enhancing the magnetic field balances the local high sputtering flux caused by the electric field effect at the sample edge, achieving layer-by-layer sputtering and obtaining a flat-bottomed sputtering pit, thereby obtaining excellent signal intensity and depth resolution.

[0059] It should be noted that the effect of the above-mentioned control device on the sputtering pit morphology is related to the discharge parameters of glow discharge mass spectrometry, especially the pressure of argon gas, that is, the number density of argon atoms. Therefore, the control effect of a specific spherical magnet array control device on sputtering is only significant within a certain range of argon gas pressure. Therefore, this invention designs different through-hole spacings and does not limit the type and size of the spherical magnets used.

[0060] According to another aspect of the invention, reference is made to the appended specification. Figures 1 to 3 The present invention further provides a method for using a magnetic field device for controlling glow discharge mass spectrometry depth sputtering as described in any one of the above, comprising the steps of:

[0061] A first spherical magnet 4 is installed in the first through hole, and six second spherical magnets 5 are respectively installed in the corresponding second through holes. The magnetic poles of the six second spherical magnets 5 are in the same direction and are all parallel to the height of the insulating plate 3. The magnetic poles of the first spherical magnet 4 are opposite to those of the second spherical magnets 5. For example, the N pole of the first spherical magnet 4 faces upward, and the S poles of the six surrounding second spherical magnets 5 face upward; or the S pole of the first spherical magnet 4 faces upward, and the N poles of the six surrounding second spherical magnets 5 face upward, such as... Figure 2As shown, a ring-shaped permanent magnet array is constructed according to the above method.

[0062] An insulating plate 3, to which a first spherical magnet 4 and a second spherical magnet 5 are fixed, is placed into a housing 1, and then a cover 2 is fitted over the opening of the housing 1. A cylindrical polytetrafluoroethylene (PTFE) insulating plate 3, to which an array of annular permanent magnets is fixed, is placed into a hollow cylindrical copper housing 1. The cylindrical PTFE insulating plate 3 is then wrapped with a copper cover 2. The outer cylindrical copper housing 1 and the copper cover 2 serve as a container and conduct electricity.

[0063] The sample 7 is placed in the middle position on the side of the cover 2 away from the shell 1, so that the limiting part limits the sample 7, thereby preventing the sample 7 from shifting during loading, injection, and analysis. By placing the sample 7 on top of the cover 2, the sample 7 is fixed to the central area of ​​the upper surface of the cover 2 by four small cuboid protrusions 6, ensuring that the sample will not shift during loading, injection, and analysis, and also ensuring that it remains within a specific area with a specific spatially distributed magnetic field, such as... Figure 3 As shown, the height of the upper surface of sample 7 from the spherical magnet array is 2.00 mm, which is the sum of the thickness of the cover 2 and the thickness of sample 7 itself. The ring permanent magnet array control device is now complete and needs to be fixed into the sample injection device.

[0064] Furthermore, it also includes the following steps:

[0065] Tantalum sheet 9, first insulating ceramic sheet 10 and second insulating ceramic sheet 11 are sequentially placed into first housing 8. One end of second housing 12 is inserted into first housing 8 and threadedly connected to first housing 8, so that second housing 12 clamps and fixes tantalum sheet 9, first insulating ceramic sheet 10 and second insulating ceramic sheet 11 between the bottom of first housing 8 and the end of second housing 12.

[0066] The assembled housing 1 is placed inside the second housing 12, and the third housing 13 is threaded to the end of the second housing 12 away from the first housing 8, so that the overall structure is supported on the second insulating ceramic sheet 11 by the elastic member 14. The sample 7 is located on the side close to the second insulating ceramic sheet 11, and the housing 1 is located on the side close to the elastic member 14.

[0067] The injection rod 15 is threaded to the third outer shell 13, and the overall structure assembled from the first outer shell 8, the second outer shell 12, and the third outer shell 13 is pushed into the glow discharge mass spectrometer cell through the injection rod 15.

[0068] In this embodiment, an external voltage is applied to the sample feed rod 15. The elastic element 14, the housing 1 of the ring permanent magnet array control device, and the sample 7 are all made of conductive metal, and the surface of the sample 7 is charged. The negative terminal of the high-voltage power supply is connected to the sample feed rod 15. The sample 7 serves as the cathode of the glow discharge, and the first metal outer shell 8 and the grounded discharge battery serve as the anode. The circular openings of the tantalum sheet 9, the first insulating ceramic sheet 10, and the second insulating ceramic sheet 11 define the portion of the sample 7 exposed to the plasma as a circular region. The size of the circular region is determined by the diameter of the circular openings of the tantalum sheet 9 and the second insulating ceramic sheet 11. The ring permanent magnet array excites a magnetic field with a specific spatial distribution on the surface of the sample 7, and the magnetic field exhibits a centrally symmetrical distribution. Considering the transverse magnetic field, that is, the magnetic field component perpendicular to the electric field direction, the distribution characteristics of the transverse magnetic field of the designed ring permanent magnet array are as follows: the intensity is relatively small in a very small area at the center, ranging from 10.0mT to 20.0mT, while in the ring area of ​​about 5.00mm on the periphery, the intensity of the transverse magnetic field can reach about 80.0mT. Subsequently, a weak magnetic field region with a width of about 2.00mm to 3.00mm appears, with a magnetic field intensity of about 10.0mT to 40.0mT.

[0069] Example

[0070] A permanent magnet magnetic field control device was constructed using sintered NdFeB N35 spherical magnets as described above. The argon pressure was 4.7 mPa, the discharge voltage was 1.8 kV, and the discharge current was 1.0 mA. The aperture diameter of the tantalum sheet 9 and the second insulating ceramic sheet 11 was 15.00 mm, i.e., the sputtering aperture was 15.00 mm. Sample 7 was an aluminum sheet, and the duration of glow discharge mass spectrometry depth analysis was 25 min.

[0071] Comparative Example

[0072] The only difference from the example is that no ring-shaped magnetic bead array is applied.

[0073] The sputtering pits left on the sample surface after sputtering in the examples and comparative examples were detected by a profilometer. The results are as follows: Figure 4 , Figure 5 As shown. Figure 4 and Figure 5 The sputtering crater morphologies obtained after depth analysis of the comparative and embodiment examples are shown respectively. The designed annular magnetic bead array control device can improve the sputtering morphology to a certain extent, making the bottom of the sputtering crater flatter. Furthermore, it is worth noting that... Figure 4 The sputtering pit depth shown is approximately 2.5 μm. Without the designed permanent magnet array control device, the edge sputtering intensity was greater than the center sputtering intensity. After applying the designed permanent magnet array magnetic field control device... Figure 5The sputtering pit depth shown reaches approximately 3.5 μm, and the difference between the sputtering depth in the central region and the edge region is reduced. According to existing research and technology, increasing the sputtering depth exacerbates sputtering inhomogeneity, leading to an uneven bottom of the sputtering pit.

[0074] The sputter crater unevenness in depth analysis of glow discharge mass spectrometry is defined as δ:

[0075]

[0076] Hmax and Hmin represent the distances from the lowest and highest points of the sputtering crater to the top of the sputtering crater, respectively. The greater the height difference (Hmax-Hmin) at the bottom of the sputtering crater, the more uneven the sputtering crater. When the height difference is the same, the smaller the average depth of the sputtering crater 0.5×(Hmax+Hmin), the more uneven the sputtering crater.

[0077] Comparing the embodiments and comparative examples, the sputtering pit unevenness was calculated to be 0.092 and 0.184, respectively, indicating that the shape of the sputtering pit was improved after using the annular magnetic bead array control device designed in this invention, which is beneficial to improving the accuracy of depth analysis.

[0078] like Figure 6 As shown, by comparing the signal strength of the embodiment and the comparative example (without using a magnetic field control device), the signal strength of the major element aluminum is 1.25×10-11A and 7.73×10-12A, respectively. The signal strength of the major element is increased by nearly 1.6 times. The designed permanent magnet array magnetic field control device can enhance the element signal strength.

[0079] The magnetic field control device of the annular magnetic bead array involved in this invention patent, based on the basic principle of magnetic field enhanced sputtering, improves the shape of sputtering pits by designing a permanent magnet array with a specific spatial magnetic field distribution, and also enhances the signal intensity. It is suitable for glow discharge mass spectrometers or similar instruments.

[0080] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0081] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnetic field device for controlling glow discharge mass spectrometry depth sputtering, characterized in that, include: A housing, the housing being conductive, the housing having a hollow structure and an opening at one end; A cover body, the cover body being conductive, the cover body being adapted to cover the opening of the housing, and a limiting part being provided on the side of the cover body away from the housing, the limiting part being used to limit the sample; An insulating plate is adapted to be installed inside the housing. The insulating plate has a first through hole and six second through holes along the height direction. The six second through holes are evenly arranged around the first through hole. A first spherical magnet is adapted to be installed in the first through hole. The diameter of the first spherical magnet is smaller than the depth of the first through hole. A second spherical magnet is adapted to be installed in each second through hole. The diameter of the second spherical magnet is smaller than the depth of the second through hole. The magnetic poles of the six second spherical magnets are in the same direction and are all parallel to the insulating plate along the height direction. The magnetic poles of the first spherical magnets are in the opposite direction to the magnetic poles of the second spherical magnets.

2. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to claim 1, characterized in that, Both the shell and the cover are made of copper, and both the shell and the insulating plate are cylindrical structures.

3. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to claim 2, characterized in that, The limiting part includes a plurality of protrusions, which surround to form a receiving space that matches the outer contour of the sample. The sample is fitted into the receiving space, so that the plurality of protrusions limit the sample.

4. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to claim 3, characterized in that, The document describes the presence of four protrusions, each of which is square in structure. These four protrusions form a square accommodating space, and the distances from the four protrusions to the center of the top of the cover are equal.

5. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to claim 2, characterized in that, The insulating plate is a polytetrafluoroethylene plate, and the diameter of the first through hole is smaller than the diameter of the first spherical magnet, so that the first spherical magnet and the first through hole are interference fit. The diameter of the second through hole is smaller than the diameter of the second spherical magnet, so that the second spherical magnet and the second through hole are in an interference fit.

6. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to claim 5, characterized in that, The insulating plate is detachably installed inside the housing. Multiple insulating plates are provided, and the distance between two adjacent second through holes on the multiple insulating plates is different, so that when the second spherical magnet is installed on different insulating plates, the distance between the second spherical magnets is different.

7. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to claim 5, characterized in that, Both the first spherical magnet and the second spherical magnet are sintered NdFeB spherical magnets. The six second spherical magnets have the same model number, and the first spherical magnet may have the same model number as or different model number from the second spherical magnet.

8. The magnetic field device for controlling glow discharge mass spectrometry depth sputtering according to any one of claims 1-7, characterized in that, Also includes: The first outer shell is conductive and has a hollow structure with an opening at one end. A tantalum sheet, a first insulating ceramic sheet, and a second insulating ceramic sheet are sequentially disposed inside the first outer shell. The second outer shell is made of insulating material. One end of the second outer shell is inserted into the first outer shell and threadedly connected to the first outer shell, so that the second outer shell clamps and fixes the tantalum sheet, the first insulating ceramic sheet and the second insulating ceramic sheet between the bottom of the first outer shell and the end of the second outer shell. The third outer shell is made of insulating material and is detachably connected to the end of the second outer shell away from the first outer shell. An elastic element is provided inside the third outer shell, and a sample inlet rod is connected to the end of the third outer shell away from the second outer shell. The sample, the cover, the insulating plate, and the shell are assembled into one unit and installed inside the second outer shell. The overall structure is supported on the second insulating ceramic sheet by the elastic element. The sample is located on the side closer to the second insulating ceramic sheet, and the shell is located on the side closer to the elastic element.

9. A method for using a magnetic field device for controlling glow discharge mass spectrometry depth sputtering as described in any one of claims 1-8, characterized in that, Including the following steps: A first spherical magnet is installed in the first through hole, and six second spherical magnets are installed in the corresponding second through holes. The magnetic poles of the six second spherical magnets are in the same direction and are all parallel to the height of the insulating plate. The magnetic poles of the first spherical magnet are opposite to the magnetic poles of the second spherical magnets. An insulating plate with the first spherical magnet and the second spherical magnet fixed on it is placed into the housing, and then the cover is fitted and placed over the opening of the housing. The sample is placed in the middle of the side of the cover away from the shell, so that the limiting part limits the sample and prevents the sample from shifting during filling, injection and analysis.

10. The method according to claim 9, characterized in that, It also includes the following steps: A tantalum sheet, a first insulating ceramic sheet, and a second insulating ceramic sheet are sequentially placed inside a first outer shell. One end of a second outer shell is inserted into the first outer shell and threadedly connected to the first outer shell, such that the second outer shell clamps and fixes the tantalum sheet, the first insulating ceramic sheet, and the second insulating ceramic sheet between the bottom of the first outer shell and the end of the second outer shell. The assembled housing is placed inside the second housing, and the third housing is threaded to the end of the second housing away from the first housing, so that the overall structure is supported on the second insulating ceramic sheet by an elastic element. The sample is located on the side closer to the second insulating ceramic sheet, and the housing is located on the side closer to the elastic element. The injection rod is threaded to the third outer shell, and the assembled structure of the first outer shell, the second outer shell, and the third outer shell is pushed into the glow discharge mass spectrometer cell through the injection rod.

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