A beam monitor

Abstract

The utility model discloses a beam monitor, apply to the beam value detection of beam source in molecular epitaxial equipment, beam monitor includes: the grid is the conductive structure of hollow cylinder, the collecting electrode is the linear conductive structure of coinciding with the central axis of grid, the ionization wire and the collecting electrode parallel each other and set up in the outside of grid, the protection cylinder sets up in the end of grid and telescopic component connection, and the end of grid, collecting electrode and ionization wire all set up in the protection cylinder, the effective collection section on collecting electrode is not more than the particle radiation interval of each beam source in the overlapping collection section on the line of collecting electrode and is located in the overlapping collection section, or, the effective ionization section of ionization wire is not more than the particle radiation interval of each beam source in the overlapping ionization section on the line of ionization wire and is located in the overlapping ionization section. In the application, the measurement error caused by the different relative positions between each beam source and hot negative ion rule can be avoided, and the accuracy and reliability of beam value detection are ensured.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, and in particular to a beam monitor. Background Technology

[0002] Molecular beam epitaxy (MBE) is a controlled growth technique for epitaxial thin films at the atomic or molecular level. Its basic principle involves evaporating the elemental materials constituting the thin film using methods such as resistance heating or electron beam heating in an ultra-high vacuum environment, and then spraying the vapor onto a heated substrate surface to grow the film. (Refer to...) Figure 1 A molecular beam epitaxy (MBE) apparatus may include a vacuum cavity 1, multiple beam sources 3 extending into and surrounding the vacuum cavity 1, and a rotatable sample stage 2 disposed within the vacuum cavity 1. Each beam source 3 is located below the sample stage 2 and ejects atomic or molecular materials onto the semiconductor sample on the sample stage 2 at an angle upwards. To ensure the precision of epitaxial film growth control, the MBE apparatus also includes a beam flux monitor (BFM) that extends into the vacuum cavity to measure the flow rate of atoms or molecules ejected by each beam source 3. However, when the beam flux monitor measures the flow rate of atoms or molecules from beam sources at different orientations, the accuracy of the measured beam value may be affected by the different angles between the direction of the ejected atoms or molecules and the beam flux monitor. Utility Model Content

[0003] The purpose of this invention is to provide a beam monitor that can improve the accuracy and reliability of beam value detection results for each beam source in molecular epitaxy equipment to a certain extent.

[0004] To solve the above-mentioned technical problems, this utility model provides a beam monitor for detecting the beam current value of a beam source in a molecular epitaxy device; the beam monitor includes: a telescopic component and a hot cathode ion gauge; the hot cathode ion gauge includes a grid, a collecting electrode, an ionization wire, and a protective sleeve;

[0005] The gate is a cylindrical hollow conductive structure; the collector is a linear conductive structure that coincides with the central axis of the gate; the ionization wire and the collector are arranged parallel to each other outside the gate; the protective cylinder is arranged at the end where the gate and the telescopic assembly are connected, and the ends of the gate, the collector, and the ionization wire are all arranged inside the protective cylinder.

[0006] The effective collection section on the collecting electrode for collecting ionized particles is a set collection section; the set collection section is not larger than the overlapping collection section of the particle radiation range of each beam source on the straight line where the collecting electrode is located, and is located within the overlapping collection section.

[0007] Alternatively, the effective ionization section on the ionization wire that can ionize the particles output by the beam source is a set ionization section; the set ionization section is not larger than the overlapping ionization section of the particle radiation range of each beam source on the straight line where the ionization wire is located, and is located within the overlapping ionization section.

[0008] In an optional embodiment of this application, if the effective collection section on the collecting electrode is the set collection section, a first shielding tube is provided on the collecting electrode to cover a portion of the collecting electrode, so that the section on the collecting electrode not covered by the first shielding tube is the set collection section.

[0009] In one optional embodiment of this application, the first shielding tube is a ceramic tube.

[0010] In an optional embodiment of this application, the first end of the first shielding tube is located inside the protective cylinder, and a miniature telescopic motor is provided between the first end of the first shielding tube and the telescopic assembly for driving the first shielding tube and the collecting electrode to move along the length direction of the collecting electrode, so as to adjust the length of the effective collecting section of the collecting electrode.

[0011] In an optional embodiment of this application, if the effective ionization section on the ionization wire is the set ionization section, a second shielding tube is sleeved on the ionization wire to cover a portion of the ionization wire, so that the section on the ionization wire not covered by the second shielding tube is the set ionization section.

[0012] In an optional embodiment of this application, the first end of the second shielding tube is located inside the protective cylinder, and a miniature telescopic motor is provided between the first end of the second shielding tube and the telescopic assembly for driving the second shielding tube and the ionization wire to move along the length direction of the ionization wire, so as to adjust the length of the effective collection section of the ionization wire.

[0013] In one optional embodiment of this application, the set collection section is the overlapping radiation section of the particle radiation intervals corresponding to the first beam source and the second beam source on the collection electrode;

[0014] The defined ionization section is the overlapping radiation section on the ionization wire corresponding to the particle radiation ranges of the first beam source and the second beam source, respectively.

[0015] Wherein, the first beam source and the second beam source are the beam sources with the largest and smallest horizontal angles between the particle output center direction and the collecting electrode, respectively.

[0016] In an optional embodiment of this application, the relative positions of the collecting electrode and the ionizing wire with respect to the gate in the length direction of the collecting electrode are independently adjustable, so that when the effective collecting section of the collecting electrode is the set collecting section, the ionizable section of the ionizing wire is not less than the maximum effective ionization section, and when the effective ionization section of the ionizing wire is the set ionization section, the collectable section of the collecting electrode is not less than the maximum effective collecting section.

[0017] Wherein, the maximum effective ionization section is the radiation section on the ionization wire that includes the particle radiation range of all the beam sources;

[0018] The maximum effective collection section includes the radiation section on the collection electrode from which the particle radiation range of all the beam sources is located.

[0019] In one optional embodiment of this application, the protective cylinder is a metal cylinder.

[0020] In an optional embodiment of this application, a movable connector is provided between the protective cylinder and the telescopic assembly, so that the relative position between the protective cylinder and the gate in the length direction of the collecting electrode is adjustable.

[0021] This invention provides a beam monitor for detecting the beam current value of a beam source in a molecular epitaxy device. The beam monitor includes a telescopic component and a hot cathode ion gauge. The hot cathode ion gauge includes a grid, a collector electrode, an ionization wire, and a protective sleeve. The grid is a cylindrical, hollow conductive structure. The collector electrode is a linear conductive structure that coincides with the central axis of the grid. The ionization wire and the collector electrode are arranged parallel to each other outside the grid. The protective sleeve is located at the end where the grid and the telescopic component are connected, and the ends of the grid, the collector electrode, and the ionization wire are all located inside the protective sleeve. The effective collection section on the collector electrode for collecting ionized particles is a set collection section. The set collection section is no larger than the overlapping collection section of the particle radiation range of each beam source on the straight line where the collector electrode is located, and is located within the overlapping collection section. Alternatively, the effective ionization section on the ionization wire that can ionize the particles output by the beam source is a set ionization section. The set ionization section is no larger than the overlapping ionization section of the particle radiation range of each beam source on the straight line where the ionization wire is located, and is located within the overlapping ionization section.

[0022] In this application, the effective collection section on the collecting electrode is set as the set collection section, or the effective ionization section on the ionization wire is set as the set ionization section. The set collection section is no larger than the overlapping collection section of the particle radiation range of each beam source on the straight line where the collecting electrode is located, and is located within the overlapping collection section. Thus, when the effective collection section of the collecting electrode is the set collection section, during the radiation process from the beam source at different positions to the collecting electrode after being ionized by the ionization wire, only the charged particles that can reach the set effective section on the collecting electrode can be collected, while particles outside the set collection section will not be collected. This makes the collecting electrode have the same collection section for each beam source at different positions, thereby avoiding the problem of different measured particle flux caused by the different relative positions of each beam source with the thermal anion gauge and the different collection sections on the collecting electrode.

[0023] Similarly, the ionization zone is set to be no larger than the overlapping ionization zone of the particle radiation range of each beam source on the straight line where the ionization wire is located, and is located within the overlapping ionization zone; when the effective ionization zone of the ionization wire is the set ionization zone, only the particles output by each beam source that can reach the set ionization zone are ionized by the ionization wire and then collected by the collecting electrode. This means that the ionization wire has the same ionization zone for each beam source at different positions, which can also avoid the problem of different measured particle flux caused by the different relative positions of each beam source and the thermal anion gauge.

[0024] Therefore, in order to ensure that the size of the collection or ionization section of each beam source is the same during the detection of particle flux from beam sources at different positions by the hot cathode ion gauge, the particles that can be detected ultimately come from radiation regions of the same size (i.e., the radiation regions of the beam source output particles). This avoids measurement errors in particle flux caused by the different relative positions of each beam source and the hot cathode ion gauge, and effectively ensures the accuracy and reliability of the beam monitor in detecting the beam values ​​of each beam source in the molecular epitaxy device. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a molecular epitaxy device;

[0027] Figure 2 This is a schematic diagram of the structure of an existing beam monitor;

[0028] Figure 3 for Figure 2 A schematic diagram of the radiation regions of the particles emitted by each beam source.

[0029] Figure 4 A schematic diagram of a beam monitor provided in an embodiment of this application;

[0030] Figure 5 for Figure 4 A schematic diagram of the radiation regions of the particles emitted by each beam source.

[0031] Figure 6 A schematic diagram of a beam monitor provided in an embodiment of this application;

[0032] Figure 7 for Figure 6 A schematic diagram of the radiation regions of the particles emitted by each beam source.

[0033] In the attached figures: 1 is a vacuum cavity, 2 is a sample stage, 3 is a beam source, 31 is a first beam source, 32 is a second beam source, 4 is a telescopic component, 5 is a hot cathode ion gauge, 51 is a grid, 52 is a collecting electrode, 53 is an ionization wire, 54 is a protective tube, 61 is a first shielding tube, and 62 is a second shielding tube. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] like Figure 1 and Figure 2 As shown, in the molecular epitaxy apparatus, each beam source 3 is arranged in a ring below the sample stage 2, and each beam source 3 radiates molecules or atoms obliquely upwards. It can be understood that the radiation region of the output particles from each beam source 3 is a conical region in three-dimensional space. In the beam monitor, the telescopic component 4 drives the hot cathode ion gauge 5 to extend below the sample stage 2 in a direction parallel to the radial direction of the sample stage 2, and roughly directly opposite the central region of the sample stage 2; thus, the ionization wire 53 and the collecting electrode 52 in the beam monitor are also roughly parallel to the radial direction of the sample stage 2.

[0036] like Figure 2 and Figure 3As shown, when each beam source 3 continuously outputs any kind of particle from molecules or atoms, some particles can reach the ionization wire 53 and be ionized by the ionization wire 53 to form charged particles. These charged particles continue to move forward and, under the action of the electric field between the grid 51 and the collector 52, move more rapidly toward the collector 52 and are eventually collected by the collector 52. The collector 52 can generate signals of different magnitudes based on the different number of particles it collects to form a beam value that characterizes the particle flux output by the beam source 3.

[0037] It should be noted that in the hot cathode ion gauge 5, the distance between the collecting electrode 52 and the ionization wire 53 is actually relatively small, and the influence of the grid 51 and the collecting electrode 52 on the direction of motion of the charged particles is also relatively small. Therefore, in this application, it can be considered that the particles output from the beam source 3 pass through the ionization wire 53 and the collecting electrode 52 in sequence from the beam source 3 and are in a straight line motion with the direction of motion unchanged.

[0038] It is understandable that the radiation region of the particles output by each beam source 3 is a conical region in three-dimensional space; furthermore, the distance between the collecting electrode 52 and the ionization wire 53 is negligible compared to the distance between the hot cathode ion gauge 5 and the beam source 3. Therefore, for each beam source 3, the collecting electrode 52 and the ionization wire 53 can be considered to be located on the same straight line; thus, as... Figure 2 As shown, for the linear collecting electrode 52 and ionizing wire 53, they can obviously only ionize and collect particles within a triangular radiation region within the conical region of the output particles of each beam source 3, that is, as... Figure 2 and Figure 3 The S10 and S20 radiation regions are shown in the diagram; while Figure 2 and Figure 3 The S30 radiation region is the area where the particles emitted by the two beam sources 3 overlap. Figure 3 To retain only Figure 2 The diagram shows the beam sources 3, the collecting electrode 52, and the ionization wire 53, as well as the radiation region of some beam sources radiating output particles. This helps to understand how the collecting electrode 52 and the ionization wire 53 work together to ionize and collect the particles output from the beam source 3.

[0039] Based on this, since the relative positions between each beam source 3 and the hot cathode ion gauge 5 are not the same, the size of the radiation range that can be detected by the hot cathode ion gauge 5 in the particles output by each beam source 3 will also differ. Therefore, when actually performing beam value detection, even if the output particle flow rate of each beam source 3 is the same, the beam value collected by the beam monitor will also be different, thus affecting the accuracy and reliability of the beam monitor in collecting the beam value of the beam source 3 in the molecular epitaxy device.

[0040] In addition, such as Figure 2 and Figure 3 As shown, at the connection point between the hot cathode ion gauge 5 and the telescopic assembly 4, a protective sleeve 54 is also provided, which wraps around one end of the ionization wire 53 and the collecting electrode 52. Obviously, the protective sleeve 54 also blocks some of the particles from the beam source 3 from reaching the ionization wire 53 and being collected by the collecting electrode 52. The degree of blocking of the particles output by each beam source 3 by the protective sleeve 54 is also directly related to the relative position between each beam source 3 and the protective sleeve 54. It can be seen that, based on the different relative positions between each beam source 3 and the hot cathode ion gauge 5, the beam current values ​​measured by the hot cathode ion gauge 5 for the particles output by each beam source 3 are different.

[0041] Based on this, this application provides a beam monitor that, by reasonably setting the effective collection area of ​​the collecting electrode 52 or the effective ionization area of ​​the ionization wire 53, ensures that the detection area size of the particles output by each beam source 3 by the thermal anion gauge is approximately the same, thereby avoiding measurement errors introduced by the different positions of the beam source 3 and improving the accuracy and reliability of the beam monitor measurement.

[0042] like Figures 4 to 7 As shown, Figure 4 A schematic diagram of a beam monitor provided in an embodiment of this application; Figure 5 for Figure 4 A schematic diagram of the radiation regions of the particles emitted by each beam source. Figure 6 A schematic diagram of a beam monitor provided in an embodiment of this application; Figure 7 for Figure 6 A schematic diagram of the radiation regions of the output particles from each beam source.

[0043] Understandable, Figure 5 and Figure 7 For easier understanding Figure 4 and Figure 6 The illustrated embodiment will Figure 4 and Figure 6 The schematic diagram of the gate 51 and the protective cylinder 54 is omitted.

[0044] Furthermore, the beam monitor referred to in this application is mainly used in molecular epitaxy equipment to detect the beam flux output of the particle flow rate from the ring-shaped beam source 3 in the molecular epitaxy equipment.

[0045] In one specific embodiment of this application, the beam monitor may include:

[0046] Telescopic assembly 4 and hot cathode ion gauge 5; hot cathode ion gauge 5 includes grid 51, collecting electrode 52, ionization wire 53 and protective cylinder 54;

[0047] Among them, the gate 51 is a cylindrical hollow conductive structure; the collector 52 is a linear conductive structure that coincides with the central axis of the gate 51; the ionization wire 53 and the collector 52 are arranged parallel to each other on the outside of the gate 51; the protective cylinder 54 is arranged at the end where the gate 51 and the telescopic component 4 are connected, and the ends of the gate 51, the collector 52 and the ionization wire 53 are all arranged inside the protective cylinder 54.

[0048] The effective collection section for collecting ionized particles on the collecting electrode 52 is the set collection section; the set collection section is the overlapping radiation section of the particle radiation range of each beam source 3 on the collecting electrode 52.

[0049] Alternatively, the effective ionization section of the particles output by the ionizable beam source 3 on the ionization wire 53 is the set ionization section; the set ionization section is the overlapping radiation section of the particle radiation range of each beam source 3 on the ionization wire 53.

[0050] like Figure 2 , Figure 4 and Figure 6 As shown, the beam monitor in this embodiment is not significantly different from a conventional beam monitor in terms of the overall structure of the telescopic component 4 and the hot cathode particle gauge. Both have a collector 52 disposed within a cylindrical, hollowed-out grid 51, and an electric field that drives the accelerated motion of charged particles can be formed between the grid 51 and the collector 52 through an external power supply. The ionization wire 53 located outside the grid 51 is parallel to the collector 52, and a protective cylinder 54 is provided at the ends of the collector 52 and the ionization wire 53 near the telescopic component 4 to prevent short circuits between the collector 52, the grid 51, and the ionization wire 53. The protective cylinder 54 in this application can be a metal cylinder, which can serve to shield electrical signals in the environment to a certain extent.

[0051] Based on this, this application further sets the effective collection section of the collecting electrode 52 as a set collection section, or sets the effective ionization section of the ionization wire 53 as a set ionization section.

[0052] To facilitate understanding, let's first combine... Figure 2 and Figure 3 The effective collection section of the collecting electrode 52 and the effective ionization section of the ionization wire 53 are explained.

[0053] In this application, the effective collection section of the collecting electrode 52 refers to all sections of the collecting electrode 52 capable of collecting particles output from at least one beam source 3. For example... Figure 2 and Figure 3 As shown, for ease of understanding, in Figure 2 and Figure 3The radiation regions S10 and S20 shown are the two radiation regions where particles that can be ionized and collected are located from the particles radiated by the first beam source 31 and the second beam source 32, respectively. Based on Figure 2 and Figure 3 It is known that the effective collection section on the collecting pole 52 includes both the section capable of collecting particles output from the first beam source 31 and the section capable of collecting particles output from the second beam source 32; and because the positions of the first beam source 31 and the second beam source 32 relative to the collecting pole 52 are different, the sections on the collecting pole 52 that can collect particles output from the first beam source 31 and the second beam source 32 respectively are not the same; and the effective collection section of the collecting pole 52 in this application should include the section capable of collecting particles output from each beam source 3; or, in other words, the effective collection section of the collecting pole 52 should refer to the union of the sections on the collecting pole 52 capable of collecting particles output from each beam source 3.

[0054] Similarly, the effective ionization section of the ionization wire 53 in this application also includes a section capable of ionizing the particles output from each beam source 3; or, in other words, the effective ionization section of the ionization wire 53 should refer to the union of the sections on the ionization wire 53 capable of ionizing the particles output from each beam source 3.

[0055] Based on this, the following explanation will take the effective collection section on the collection pole 52 as the set collection section as an example.

[0056] Reference Figure 2 and Figure 3 It can be determined that within the effective collection section of the collecting pole 52, although the collection areas corresponding to the particles output by each beam source 3 are not the same, there are overlapping sections on the collecting pole 52 that can collect the particles output by each beam source 3, that is, as shown in the figure. Figure 2 and Figure 3The overlapping collection section indicated in the diagram is clearly the section on the collecting electrode 52 where particles output from each beam source 3 can reach and be collected; or, in other words, the overlapping collection section should be the intersection of sections on the collecting electrode 52 where particles output from each beam source 3 can be collected by the particles output from each beam source 3. Therefore, in this application, by adjusting the length of the collecting electrode 52 or adjusting the relative position of the hot cathode ion gauge 5 with respect to each beam source 3, the effective collection section of the collecting electrode 52 can be made a set collection section, which is located within the overlapping collection section and its length is not greater than the length of the overlapping collection section; alternatively, the overlapping collection section can be directly used as the set collection section. Therefore, it can be seen that the particle radiation region corresponding to the particles output by any beam source 3 in this application completely covers the set collection section. Only the set collection section on the collecting electrode 52 can receive and collect the particles output by each beam source 3. This makes the effective section size of the collecting electrode 52 in the thermionic gauge 5, which can collect particles output by beam sources 3 at different positions, the same. That is to say, the collecting electrode 52 collects particles in the same radiation region of the particle radiation region of each beam source 3. Thus, even if the positions of each beam source 3 relative to the collecting electrode 52 are different, no measurement error will be introduced. Therefore, when the thermionic gauge 5 detects the beam current value of beam sources 3 at different positions, the only factor causing the change in the beam current value is the difference in the particle flow rate output by the beam source 3. This can greatly improve the measurement accuracy of the beam monitor.

[0057] Additionally, it should be noted that although the overlapping collection section on the collecting pole 52 in this application is a section capable of collecting particles output from the beam source 3 at each different location, in practical applications, this overlapping collection section can be directly arranged according to... Figure 2 and Figure 3 The overlapping sections of the collection regions corresponding to the first beam source 31 and the second beam source 32 on the collection pole 52 are determined. Optionally, the collection region is the overlapping radiation region of the particle radiation intervals corresponding to the first beam source 31 and the second beam source 32 on the collection pole 52. The first beam source 31 and the second beam source 32 are the beam sources 3 with the largest and smallest horizontal angles between the particle output center direction and the collection pole 52, respectively.

[0058] As described above, each beam source 3 is arranged in a ring below the sample stage 2 with the central axis of the sample stage 2 as the center; and the hot cathode ion gauge 5 of the beam monitor also extends parallel to a radial direction of the sample stage 2 to the bottom of the sample stage 2; such as Figure 2 and Figure 3As shown, the angle between the center direction of the particle output of the first beam source 31 (i.e., the direction of the central axis of the conical radiation region where the output particles of the beam source 3 are distributed) and the collecting electrode 52 is the largest, which can be 180°. Conversely, the angle between the center direction of the particle output of the second beam source 32 and the collecting electrode 52 in the horizontal direction is the smallest, which can be 0°. Clearly, the first beam source 31 and the second beam source 32 should be two beam sources 3 that are symmetrical about the central axis of the sample stage 2. Obviously, on the collecting electrode 52, among the collection sections corresponding to each beam source 3, the overlapping section between the collection sections corresponding to the first beam source 31 and the second beam source 32 should be the smallest. Therefore, the overlapping section between the collection sections corresponding to the first beam source 31 and the second beam source 32 is also the common overlapping collection section of all beam sources 3 on the collecting electrode 52.

[0059] Based on the above discussion, in order to set the effective collection section of the collector 52 as the designated collection section, such as... Figure 4 and Figure 5 As shown, in an optional embodiment of this application, it may further include:

[0060] If the effective collection section on the collecting electrode 52 is the set collection section, a first shielding tube 61 is sleeved on the collecting electrode 52 to cover part of the collecting electrode 52, so that the section on the collecting electrode 52 not covered by the first shielding tube 61 is the set collection section.

[0061] In this embodiment, the first shielding tube 61 can be a metal shielding tube or an insulating tube, such as a ceramic tube or an insulating tubular structure of other materials. This embodiment does not specifically limit this, as long as the area on the collecting electrode 52 covered by the first shielding tube 61 cannot collect ionized charged particles. The inner diameter of the first shielding tube 61 should be larger than the cross-sectional diameter of the collecting electrode 52 to ensure that the collecting electrode 52 can be inserted into the first shielding tube 61. Of course, this application does not exclude the possibility that the inner wall of the first shielding tube 61 is directly attached to and wrapped around a portion of the surface of the collecting electrode 52. In this case, the first shielding tube 61 should be a tubular structure formed of insulating material, such as insulating resin.

[0062] like Figure 4 and Figure 5As shown, the first end of the collecting electrode 52 is connected to the telescopic assembly 4, and the second end is away from the telescopic assembly 4; the first end of the first shielding tube 61 is also close to the telescopic assembly 4, while the second end is away from the telescopic assembly 4. Furthermore, the first end of the first shielding tube 61 should extend into the interior of the protective cylinder 54. Therefore, the section on the collecting electrode 52 between the second end of the collecting electrode 52 and the second end of the first shielding tube 61 is the effective collecting section of the collecting electrode 52. It is understood that in practical applications, the telescopic assembly 4 should also reasonably drive the hot cathode ion gauge 5 to extend and retract below the sample stage 2, ensuring that the second end of the collecting electrode 52 is located precisely at the edge point of one side of the overlapping collecting section or inside the overlapping collecting section, while the second end of the first shielding tube 61 is located at the edge point of the other side of the overlapping collecting section or inside the overlapping collecting section. This ensures that the section on the collecting electrode 52 not covered by the first shielding tube 61 is the designated collecting section and is located within the overlapping collecting section.

[0063] Furthermore, in another optional embodiment of this example, it may further include:

[0064] The first end of the first shielding tube 61 is located inside the protective cylinder 54, and a miniature telescopic motor is provided between the first end of the first shielding tube 61 and the telescopic assembly 4 to drive the first shielding tube 61 and the collecting electrode 52 to move along the length direction of the collecting electrode 52, so as to adjust the length of the effective collecting section of the collecting electrode 52.

[0065] In this embodiment, a miniature telescopic motor is provided between the first shielding tube 61 and the telescopic assembly 4, so that the first shielding tube 61 can move relative to the collecting electrode 52 along its length; for example Figure 4 and Figure 5 As shown, when the micro telescopic motor drives the first shielding tube 61 to move towards the second end of the collecting electrode 52, the length of the effective collecting section on the collecting electrode 52 can be reduced. Conversely, when the micro telescopic motor drives the first shielding tube 61 to move towards the first end of the collecting electrode 52, the length of the effective collecting section on the collecting electrode 52 can be increased. Therefore, in practical applications, the length of the effective collecting section on the collecting electrode 52 can be flexibly adjusted based on the actual layout of each beam source 3 and the radiation range of the emitted particles, thereby adapting to various different measurement environments.

[0066] Furthermore, it is understandable that in practical applications, the first shielding tube 61 can be a rigid, non-stretchable tubular structure, thereby using a micro motor to adjust the length of the section covering the collecting electrode 52; however, the first shielding tube 61 may also be a flexible tube with adjustable length, or a tubular structure consisting of multiple interlocking segments. In short, by adjusting the overall length of the first shielding tube 61, the length of the section covering the collecting electrode 52 can be adjusted, thereby adjusting the length of the effective collecting area on the collecting electrode 52.

[0067] Based on this, in order to ensure that all particles output from each beam source 3 that can reach the designated collection section on the collector 52 can be ionized by the ionization wire 53, in another optional embodiment of this embodiment, it may further include:

[0068] The relative positions of the collector 52 and the ionization wire 53 with respect to the gate 51 in the length direction of the collector 52 are independently adjustable, so that when the effective collection section of the collector 52 is the set collection section, the ionizable section of the ionization wire 53 is not less than the maximum effective ionization section.

[0069] The maximum effective ionization region is the radiation region on the straight line where the ionization wire 53 is located, which includes the particle radiation range of all beam sources 3.

[0070] like Figure 4 and Figure 5 As shown, when the effective collection section of the collecting electrode 52 is the set collection section, the ionization sections of the particles that can reach the set collection section output by each beam source 3 are often relatively dispersed on the ionization wire 53. Therefore, in order to ensure that all particles that can reach the set collection section output by each beam source 3 can be ionized by the ionization wire 53, the length of the section on the ionization wire 53 that can ionize particles should be as large as possible.

[0071] As mentioned earlier, for each beam source 3, the particles radiated out by it form a conical spatial region in three-dimensional space. The intersection of this conical spatial region and the straight line containing the ionization wire 53 is the radiation segment of the particle radiation range of that beam source 3 on the ionization wire 53. Correspondingly, the maximum effective ionization segment is the union of the radiation segments corresponding to each beam source 3 on the ionization wire 53. Therefore, the segment on the ionization wire 53 that can ionize the particles output by the beam source 3 should at least include this maximum effective ionization segment.

[0072] To ensure that the ionizable section on the ionization wire 53 includes the maximum effective ionization section, both the collector electrode 52 and the ionization wire 53 can be configured to be movable and adjustable relative to the grid 51 along the length of the collector electrode 52. This allows the ionization wire 53 and the collector electrode 52 to cooperate with each other, ensuring that only particles that can reach the designated collection section on the collector electrode 52 can be ionized, while ensuring that the particles output from each beam source 3 are fully ionized. This further guarantees the accuracy and reliability of the beam monitor measurement results.

[0073] Furthermore, as mentioned earlier, both the collecting electrode 52 and the end of the ionization wire 53 near the telescopic assembly 4 are located inside the protective cylinder 54, which also hinders particle ionization and collection to some extent. Therefore, in an optional embodiment of this invention, the protective cylinder 54 and the gate 51 can also be relatively movable along the length of the collecting electrode 52 to adjust their relative positions, thereby adjusting the effective collection section on the collecting electrode 52.

[0074] In the above embodiments, the effective collection section on the collecting electrode 52 is mainly used as the set collection section for explanation. The following will describe a specific embodiment using the effective ionization section on the ionization wire 53 as the set ionization section.

[0075] like Figure 6 and Figure 7 As shown, in Figure 6 and Figure 7 In the embodiment shown, the effective ionization section on the ionization wire 53 is the set ionization section, and a second shielding tube 62 is sleeved on the ionization wire 53 to cover part of the ionization wire 53, so that the section on the ionization wire 53 not covered by the second shielding tube 62 is the set ionization section.

[0076] It is understood that the principle of setting the second shielding tube 62 on the ionization wire 53 in this embodiment is exactly the same as the method of setting the first shielding tube 61 on the collecting electrode 52. The section from the end of the ionization wire 53 away from the telescopic component 4 to the end of the second shielding tube 62 away from the telescopic component 4 is the set ionization section. The set ionization section should be included in the overlapping ionization section, or be the same as the overlapping ionization section.

[0077] Based on this, the second shielding tube 62 can also be a metal shielding tube, an insulating ceramic tube, or an insulating resin tube, etc., and can be referred to the first shielding tube 61 for details. This application will not repeat the description.

[0078] Furthermore, the first end of the second shielding tube 62 is located inside the protective cylinder 54, and a miniature telescopic motor is provided between the first end of the second shielding tube 62 and the telescopic assembly 4 to drive the second shielding tube 62 and the ionization wire 53 to move along the length direction of the ionization wire 53, so as to adjust the length of the effective collection section of the ionization wire 53.

[0079] Similar to the first shielding tube 61 mentioned above, the second shielding tube 62 in this application can also move relative to the ions along the length of the ionization wire 53, thereby adapting to the measurement requirements under different measurement conditions.

[0080] Furthermore, similar to the determination of the overlapping collection section mentioned above, in this embodiment, the overlapping radiation section of the first beam source 31 and the second beam source 32 on the ionization wire 53 can also be used to determine the overlapping ionization section of all beam sources 3 on the ionization wire 53, and then the overlapping ionization section is used as the set ionization section; wherein, the first beam source 31 and the second beam source 32 are the beam sources 3 with the largest and smallest horizontal angles between the particle output center direction and the collection electrode 52, respectively.

[0081] Further optionally, when the effective ionization section of the ionization wire 53 is the set ionization section, the collectable section of the collecting electrode 52 is not less than the maximum effective collection section;

[0082] The maximum effective collection section includes the radiation section of the particle radiation range of all beam sources 3 on the collection pole 52.

[0083] Similar to the maximum effective ionization region mentioned above, for each beam source 3, the emitted particles form a conical spatial region in three-dimensional space. The intersection of this conical spatial region and the straight line containing the collecting electrode 52 is the radiation segment of the particle radiation range of that beam source 3 on the straight line containing the collecting electrode 52. Correspondingly, the maximum effective collection segment is the union of the radiation segments corresponding to each beam source 3 on the collecting electrode 52. Therefore, the segment on the collecting electrode 52 that can collect the particles output by the beam source 3 should at least include this maximum effective collection segment.

[0084] To ensure that the collectable section on the collector electrode 52 includes the maximum effective collection section, both the collector electrode 52 and the ionization wire 53 can be adjusted to move relative to the gate 51 along the length of the collector electrode 52. This allows the ionization wire 53 and the collector electrode 52 to cooperate with each other, ensuring that all particles output from each beam source 3 that can be ionized by the set ionization section on the ionization wire 53 can be collected and measured by the collector electrode 52, further ensuring the accuracy and reliability of the beam monitor measurement results.

[0085] Furthermore, a movable connector is provided between the protective cylinder 54 and the telescopic assembly 4 so that the movement adjustment of the protective cylinder 54 relative to the grid 51 in the length direction of the collector 52 can also realize the adjustment of the effective ionization section of the ionization wire 53.

[0086] In summary, this application sets the effective collection section on the collecting electrode as a set collection section, or sets the effective ionization section on the ionization wire as a set ionization section. The set collection section is no larger than the overlapping collection section of the particle radiation ranges of each beam source on the straight line where the collecting electrode is located, and is located within the overlapping collection section. Therefore, when the effective collection section of the collecting electrode is the set collection section, during the radiation process from beam sources at different positions after ionization by the ionization wire towards the collecting electrode, only particles that can reach the set effective section on the collecting electrode can be collected, while particles outside this set collection section will not be collected. This ensures that the collecting electrode has the same collection section for beam sources at different positions, thus avoiding the problem of different measured particle fluxes caused by different relative positions of each beam source to the thermal anion gauge, resulting in different collection sections on the collecting electrode. Similarly, the set ionization section is no larger than the overlapping collection section of the particle radiation ranges of each beam source on the straight line where the ionization wire is located. The ionization zone is overlapped and located within the overlapping ionization zone. When the effective ionization zone of the ionization wire is the set ionization zone, only particles output from each beam source that can reach the set ionization zone are ionized by the ionization wire and then collected by the collecting electrode. This ensures that the ionization wire has the same ionization zone for each beam source at different positions, thus avoiding the problem of different measured particle flux caused by different relative positions between each beam source and the thermal anion gauge. Therefore, in order to ensure that the size of the collection or ionization zone of each beam source is the same during the detection of particle flux output from beam sources at different positions by the thermal anion gauge, the particles that can be detected ultimately come from the radiation area of ​​the same size (i.e., the radiation area of ​​the beam source output particles), avoiding the measurement error of particle flux introduced by different relative positions between each beam source and the thermal anion gauge, and effectively ensuring the accuracy and reliability of the beam current value detection of each beam source in the molecular epitaxy device by the beam monitor.

[0087] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0088] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A beam monitor, characterized in that, A beam current monitor is used for detecting the beam current value of a beam source in a molecular epitaxy device. The beam current monitor includes a telescopic component and a hot cathode ion gauge. The hot cathode ion gauge includes a grid, a collecting electrode, an ionization wire, and a protective sleeve. The gate is a cylindrical hollow conductive structure; the collector is a linear conductive structure that coincides with the central axis of the gate; the ionization wire and the collector are arranged parallel to each other outside the gate; the protective cylinder is arranged at the end where the gate and the telescopic assembly are connected, and the ends of the gate, the collector, and the ionization wire are all arranged inside the protective cylinder. The effective collection section on the collecting electrode for collecting ionized particles is a set collection section; the set collection section is not larger than the overlapping collection section of the particle radiation range of each beam source on the straight line where the collecting electrode is located, and is located within the overlapping collection section. Alternatively, the effective ionization section on the ionization wire that can ionize the particles output by the beam source is a set ionization section; the set ionization section is not larger than the overlapping ionization section of the particle radiation range of each beam source on the straight line where the ionization wire is located, and is located within the overlapping ionization section.

2. The beam monitor as described in claim 1, characterized in that, If the effective collection section on the collecting electrode is the set collection section, a first shielding tube is provided on the collecting electrode to cover a portion of the collecting electrode, so that the section on the collecting electrode not covered by the first shielding tube is the set collection section.

3. The beam monitor as described in claim 2, characterized in that, The first shielding tube is a ceramic tube.

4. The beam monitor as described in claim 2, characterized in that, The first end of the first shielding tube is located inside the protective cylinder, and a miniature telescopic motor is provided between the first end of the first shielding tube and the telescopic assembly to drive the first shielding tube and the collecting electrode to move along the length direction of the collecting electrode, so as to adjust the length of the effective collecting section of the collecting electrode.

5. The beam monitor as described in claim 1, characterized in that, If the effective ionization section on the ionization wire is the set ionization section, a second shielding tube is sleeved on the ionization wire to cover a portion of the ionization wire, so that the section on the ionization wire not covered by the second shielding tube is the set ionization section.

6. The beam monitor as described in claim 5, characterized in that, The first end of the second shielding tube is located inside the protective cylinder, and a miniature telescopic motor is provided between the first end of the second shielding tube and the telescopic assembly to drive the second shielding tube and the ionization wire to move along the length direction of the ionization wire, so as to adjust the length of the effective collection section of the ionization wire.

7. The beam monitor as described in claim 1, characterized in that, The designated collection section is the overlapping radiation section on the collection electrode where the particle radiation ranges corresponding to the first beam source and the second beam source are respectively located. The defined ionization section is the overlapping radiation section on the ionization wire corresponding to the particle radiation ranges of the first beam source and the second beam source, respectively. Wherein, the first beam source and the second beam source are the beam sources with the largest and smallest horizontal angles between the particle output center direction and the collecting electrode, respectively.

8. The beam monitor as described in any one of claims 1 to 7, characterized in that, The relative positions of the collecting electrode and the ionizing wire with respect to the gate along the length of the collecting electrode are independently adjustable, so that when the effective collecting section of the collecting electrode is the set collecting section, the ionizable section of the ionizing wire is not less than the maximum effective ionization section, and when the effective ionization section of the ionizing wire is the set ionization section, the collectable section of the collecting electrode is not less than the maximum effective collecting section. Wherein, the maximum effective ionization section is the radiation section on the ionization wire that includes the particle radiation range of all the beam sources; The maximum effective collection section includes the radiation section on the collection electrode from which the particle radiation range of all the beam sources is located.

9. The beam monitor as described in claim 8, characterized in that, The protective cylinder is a metal cylinder.

10. The beam monitor as described in claim 8, characterized in that, A movable connector is provided between the protective cylinder and the telescopic assembly, so that the relative position between the protective cylinder and the gate in the length direction of the collecting electrode is adjustable.

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