Position adjusting mechanism for crucible in vacuum of high-temperature beam source furnace

Abstract

The invention belongs to the technical field of MBE molecular beam epitaxy equipment, and particularly relates to a position adjusting mechanism for a vacuum inner crucible of a high-temperature beam source furnace. One end of a shell is hermetically connected with a source furnace cavity through a flange, and a driving screw rod is rotatably mounted in the other end of the shell; one end of the driving screw is connected with the coupler, the other end of the driving screw is in threaded connection with one end of the connecting rod in the shell, the other end of the connecting rod penetrates out of the shell and the flange and then is connected with one end of the control fork, and the other end of the control fork is located in the source furnace cavity and abuts against the source furnace crucible; a corrugated pipe is arranged in the shell, one end of the corrugated pipe is fixedly connected to the flange, the other end of the corrugated pipe is connected with a connecting rod, the connecting rod is fixedly connected with one end of a pointer screw, and the other end of the pointer screw extends out of the shell. The position of the crucible is adjusted outside vacuum, smooth operation of a valve control mechanism is guaranteed, the source furnace can be prevented from being disassembled and adjusted on site by a client, and the accurate requirement for controlling the concentricity of a driving structure in the using process of the source furnace can be effectively met.

Description

Technical Field

[0001] This invention belongs to the technical field of MBE molecular beam epitaxy equipment, specifically a position adjustment mechanism for a crucible inside a vacuum chamber of a high-temperature beam source furnace. Background Technology

[0002] Existing source furnace crucibles, due to structural limitations, must be located inside the source furnace cavity, surrounded by high-temperature heating components. After the source furnace is installed into the MBE (Molecular Beam Epitaxy) equipment, the position of the crucible inside the source furnace can no longer be manually controlled or adjusted. In actual use, many source furnaces are installed at an angle, and due to transportation and other operations, the crucible, especially the material-laden crucible of a large-capacity source furnace, can easily deviate from its original design position by a small distance. This causes the valve control mechanism that controls the opening and closing of the crucible to become misaligned with the crucible guide, resulting in control problems and causing issues with beam control during the use of the source furnace. Summary of the Invention

[0003] In view of the above-mentioned problems caused by the crucible in the existing source furnace deviating from its original position, the purpose of the present invention is to provide a position adjustment mechanism for the crucible in the vacuum chamber of a high-temperature beam source furnace.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention includes a control fork and a transmission assembly. The transmission assembly includes a coupling, a drive screw, a housing, a pointer screw, a connecting rod, a bellows, and a flange. One end of the housing is sealed to the source furnace cavity via the flange. The drive screw is rotatably mounted inside the other end of the housing. One end of the drive screw is connected to a coupling fixed to the housing. The other end of the drive screw is threadedly connected to one end of the connecting rod inside the housing. The other end of the connecting rod passes through the housing and flange and is connected to one end of the control fork. The other end of the control fork is located inside the source furnace cavity and is connected to the... The source furnace crucible abuts against the housing; a bellows is provided inside the housing, one end of which is fixed to a flange, and the other end of which is connected to a connecting rod. One end of a pointer screw is fixed to the connecting rod, and the other end of the pointer screw extends out of the housing and serves as a pointer that moves with the connecting rod. The pointer screw also limits the rotation of the connecting rod. The coupling drives the drive screw to rotate, and the drive screw, through a threaded connection with the connecting rod, drives the connecting rod to move axially, thereby adjusting the position of the source furnace crucible so that the source furnace crucible and the crucible plug are concentric.

[0006] Wherein: the axial cross section of the connecting rod is in the shape of a cross, the horizontal side of the cross is located inside the housing, the bellows is located between the horizontal side of the cross and the flange, the other end of the bellows is fixed to the horizontal side of the cross, and the vertical side of the cross is passed through the bellows.

[0007] One end of the pointer screw is fixed to the horizontal side of the "+" shape, and the other end of the pointer screw extends out from the strip hole opened on the housing. One or both sides of the strip hole are provided with scales along the moving direction of the connecting rod.

[0008] The other end of the housing is provided with a self-lubricating guide sleeve. The other end of the drive screw is inserted into the guide sleeve. One end of the connecting rod is provided with a threaded hole along the axial direction. The other end of the drive screw is threadedly connected to the threaded hole. One end of the connecting rod extends between the drive screw and the self-lubricating guide sleeve.

[0009] The power to drive the connecting rod to rotate can be a manually rotated coupling or a drive motor connected to the coupling.

[0010] The transmission assembly is divided into an inner vacuum section and an outer vacuum section, which are separated by the bellows. Rotating the coupling pushes the control fork in the inner vacuum section to move radially along the source furnace cavity outside the vacuum section, thereby adjusting the position of the source furnace crucible.

[0011] The transmission components are two or more, and the transmission components are located on the inclined side of the source furnace crucible inside the source furnace cavity, or the transmission components are evenly arranged along the circumferential direction.

[0012] The advantages and positive effects of this invention are as follows:

[0013] This invention controls the position of the control fork supporting the source furnace crucible on the tilted side of the source furnace within the vacuum by controlling the rotation amount of the transmission component outside the vacuum section, thereby adjusting the position of the source furnace crucible. This invention effectively avoids the process of disassembling and adjusting the source furnace at the customer's site due to vacuum breaking, reduces the precision requirements for the concentricity of the control drive structure during the use of the source furnace, and ensures the stability of the operation of large-capacity source furnaces with material. Attached Figure Description

[0014] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 This is a top sectional view of the present invention;

[0017] Figure 3 This is a schematic diagram of the structure of the present invention installed on an MBE device;

[0018] Figure 4 This is a schematic diagram of the transmission component of the present invention;

[0019] Figure 5 for Figure 4Right sectional view;

[0020] Wherein: 1 is the source furnace crucible, 2 is the source furnace cavity, 3 is the control fork, 4 is the high-temperature heating zone assembly, 5 is the transmission assembly, 6 is the coupling, 7 is the stop screw, 8 is the bearing fixing screw, 9 is the bearing, 10 is the drive screw, 11 is the self-lubricating guide sleeve, 12 is the housing, 13 is the pointer screw, 14 is the connecting rod, 15 is the long screw, 16 is the bellows, 17 is the flange, 18 is the MBE device, 19 is the strip hole, 20 is the scale, and 21 is the threaded hole. Detailed Implementation

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] like Figures 1-5 As shown, the present invention includes a control fork 3 and a transmission assembly 5. The transmission assembly 5 includes a coupling 6, a drive screw 10, a housing 12, a pointer screw 13, a connecting rod 14, a bellows 16, and a flange 17. One end of the housing 12 is sealed to the interface flange on the source furnace cavity 2 via the flange 17. The drive screw 10 is rotatably mounted inside the other end of the housing 12 via a bearing 9. The bearing 9 is fixed to the end of the other end of the housing 12 via a bearing fixing screw 8. One end of the drive screw 10 is connected to the coupling 6 fixed on the housing 12. The other end of the drive screw 10 is threadedly connected to one end of the connecting rod 14 inside the housing 12. The other end of the connecting rod 14 passes through the housing 12 and the flange 17 and then connects to... One end of the control fork 3 is connected to the source furnace cavity 2, and the other end of the control fork 3 is located inside the source furnace cavity 2 and abuts against the source furnace crucible 1; a bellows 16 is provided inside the housing 12, one end of the bellows 16 is fixed to the flange 17, and the other end of the bellows 16 is connected to the connecting rod 14. One end of the connecting rod 14 is fixed to the pointer screw 13, and the other end of the pointer screw 13 extends out of the housing 12 and serves as a pointer that moves with the connecting rod 14. The pointer screw 13 is used to limit the rotation of the connecting rod 14; the coupling 6 drives the drive screw 10 to rotate, and the drive screw 10 drives the connecting rod 14 to move axially through the threaded connection between the drive screw 10 and the connecting rod 14, thereby adjusting the position of the source furnace crucible 1 so that the source furnace crucible 1 is concentric with the crucible plug.

[0024] In this embodiment, the source furnace crucible 1 is made of pyrolytic boron nitride, with a large belly and long neck (i.e., a large diameter at the bottom and a small and long diameter at the top) to withstand high temperatures. Figure 1 The middle section only provides the lower part of the structure, while the upper neck is used in conjunction with the crucible plug. The opening and closing of the source furnace beam is controlled by a separate valve control mechanism that controls the lifting and lowering of the crucible plug. The specific dimensions of the crucible are specially designed according to the elements and capacity used in the source furnace. The upper structure of the source furnace crucible 1 is existing technology, adopting the "A guide sleeve built-in type high temperature beam source furnace beam control structure and its control method" published on March 29, 2024, with publication number CN117778961A. The source furnace crucible 1 is located inside the source furnace cavity 2 and is surrounded by the high-temperature heating zone assembly 4, which is fixed inside the source furnace cavity 2. The high-temperature heating zone assembly 4 does not move. The high-temperature heating zone assembly 4 is a prior art technology and includes a heating wire and a metal insulation layer. The metal insulation layer is fixed on the inner wall of the source furnace cavity 2, and the heating wire is wound around the outer surface of the metal insulation layer. The high-temperature heating zone assembly 4 covers the source furnace crucible 1 and the control fork 3 inside and provides a high-temperature heating field during operation, so that the elements in the source furnace crucible 1 can be decomposed to form a beam.

[0025] In this embodiment, the control fork 3 is made of a high-temperature resistant metal (such as molybdenum, titanium, or nickel) and is used to connect the transmission assembly 5. The style of the support fork of the control fork 3 is not limited and can vary according to the number and form of the circumferentially distributed transmission assemblies 5, in order to connect the transmission assemblies 5 and adjust the position of the source furnace crucible 1. In this embodiment, the other end of the control fork 3 is an arc shape that matches the lower cylinder of the source furnace crucible 1.

[0026] There are two or more transmission components 5. The transmission components 5 are located on the inclined side of the source furnace crucible 1 within the source furnace cavity 2, or the transmission components 5 are evenly arranged along the circumference to achieve omnidirectional adjustment of the source furnace crucible 1. The transmission components 5 are divided into an inner vacuum section and an outer vacuum section, separated by a bellows 16. A rotating coupling 6 pushes the control fork 3 within the vacuum section radially along the source furnace cavity 2 from the outer vacuum section, thereby adjusting the position of the source furnace crucible 1. In this embodiment, there are two transmission components 5, arranged only on the inclined side of the source furnace cavity 2.

[0027] In this embodiment, the axial cross-section of the connecting rod 14 is shaped like a cross. The horizontal side of the cross is located inside the housing 12. The bellows 16 is located between the horizontal side of the cross and the flange 17. The other end of the bellows 16 is fixed to the horizontal side of the cross, and the vertical side of the cross passes through the bellows 16. One end of the pointer screw 13 is fixed to the horizontal side of the cross, and the other end of the pointer screw 13 extends out from the slot 19 opened on the housing 12. One or both sides of the slot 19 are provided with a scale 20 along the moving direction of the connecting rod 14. The connecting rod 14 is restricted by the pointer screw 13 and the slot 19, and can only move axially to ensure that the movement of the bellows 16 is also axial and cannot rotate.

[0028] In this embodiment, a self-lubricating guide sleeve 11 is provided inside the other end of the housing 12. The self-lubricating guide sleeve 11 is prior art and will not be described in detail here; the self-lubricating guide sleeve 11 can be made of plastic. The other end of the drive screw 10 is inserted into the guide sleeve 11, and one end of the connecting rod 14 has a threaded hole 21 along the axial direction. The other end of the drive screw 10 is threadedly connected to the threaded hole 21, and one end of the connecting rod 14 extends between the drive screw 10 and the self-lubricating guide sleeve 11, so that the connecting rod 14 contacts the self-lubricating guide sleeve 11, thereby reducing friction.

[0029] In this embodiment, the power to drive the connecting rod 14 to rotate can be manually rotating the coupling 6 or being driven by a drive motor connected to the coupling 6. The drive motor can be mounted on the housing 12.

[0030] The working principle of this invention is as follows:

[0031] A crucible plug, made of pyrolytic boron nitride, is located at the upper neck outlet position of the source furnace crucible 1. The valve control mechanism must be concentric with the source furnace crucible 1. The crucible plug's movement at the neck position of the source furnace crucible 1 is controlled by a separate valve control mechanism, ensuring that the crucible plug can only move vertically axially at the neck position of the source furnace crucible 1, thereby adjusting the beam size and opening / closing during source furnace operation. After the source furnace is installed into the MBE device 18, the position of the source furnace crucible 1 can no longer be manually adjusted. If a slight displacement occurs due to transportation or installation, the upper valve control mechanism will become misaligned, directly affecting the movement of the crucible plug. This can range from affecting beam linearity and causing crucible plug wear to preventing valve opening and closing, rendering the source furnace unusable. This invention eliminates the need to disassemble the source furnace. The position of the source furnace crucible 1 can still be adjusted outside a vacuum via the transmission assembly 5, ensuring smooth operation of the upper valve control mechanism and guaranteeing the source furnace beam quality. Specifically:

[0032] Taking the MBE high-temperature beam source furnace for cracking antimony raw materials as an example, the raw antimony is stored in the lower part of the source furnace crucible 1. In the initial state, the source furnace crucible 1 is fixed to the support by the traction inside the source furnace cavity 2, and the whole is located in the high-temperature heating zone assembly 4 inside the source furnace cavity 2. On the tilted side in actual use, two transmission components 5 support the control fork 3 to straighten the bottom of the source furnace crucible 1 (e.g., Figure 2 (As shown). The upper neck of the source furnace crucible 1 contains a crucible plug controlled by a valve control mechanism. The valve control mechanism needs to keep the crucible plug and the source furnace crucible 1 concentric. Before being installed in the MBE device 18, the overall structure is as follows: Figure 1 As shown; the source furnace is installed on the MBE equipment 18 in an inclined state, as... Figure 3As shown, the antimony raw material inside the source furnace crucible 1 will inevitably move during the installation process, causing the overall position of the source furnace crucible 1 to differ from its vertical position. It will shift slightly to the tilted side. This shift at the bottom of the source furnace crucible 1 will lead to a change in the position of the top of the source furnace crucible 1, resulting in poor concentricity between the crucible plug controlled by the valve control mechanism and the source furnace crucible 1, which will directly affect the movement of the crucible plug. At this time, by adjusting the transmission assembly 5 outside the vacuum, the connecting rod 14 pushes the position of the control fork 3 inside the vacuum, thereby pushing the lower part of the source furnace crucible 1. This adjustment corrects the offset position caused by the tilted installation, allowing for quick adjustment of the source furnace valve control mechanism and facilitating the use of the source furnace. In addition, as the source furnace is used, the amount of antimony raw material inside the source furnace crucible 1 will gradually decrease, and the vertical downward gravity of the source furnace crucible 1 will also change. The position of the source furnace crucible 1 will shift upward, and the control of the valve control mechanism will deteriorate. At this time, the reverse adjustment of the transmission component 5 outside the vacuum can counteract these positional shifts, and keep the valve control of the antimony furnace in the optimal state without breaking the vacuum. This achieves good control and adjustment of the beam current size and rapid opening and closing during the operation of the high-temperature beam source furnace, ensuring the user's use.

[0033] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A position adjustment mechanism of an in-vacuum crucible of a high-temperature beam source furnace, characterized by: The control fork (3) and the transmission assembly (5) are included, wherein the transmission assembly (5) includes the shaft coupling (6), the drive screw (10), the shell (12), the pointer screw (13), the connecting rod (14), the bellows (16) and the flange (17), one end of the shell (12) is sealingly connected with the source furnace cavity (2) through the flange (17), the drive screw (10) is rotatably installed in the inside of the other end of the shell (12), one end of the drive screw (10) is connected with the shaft coupling (6) fixed on the shell (12), the other end of the drive screw (10) is threadedly connected with one end of the connecting rod (14) in the shell (12), the other end of the connecting rod (14) is connected with one end of the control fork (3) after passing through the shell (12) and the flange (17), the other end of the control fork (3) is located in the source furnace cavity (2) and abuts against the source furnace crucible (1); the shell (12) is provided with the bellows (16), one end of the bellows (16) is fixed on the flange (17), the other end of the bellows (16) is connected with the connecting rod (14), one end of the connecting rod (14) is fixed with the pointer screw (13), the other end of the pointer screw (13) is extended out of the shell (12) and serves as a pointer moving with the connecting rod (14), and the pointer screw (13) is used for limiting the rotation of the connecting rod (14); the shaft coupling (6) drives the rotation of the drive screw (10), the drive screw (10) drives the connecting rod (14) to move along the axial direction through the threaded connection between the drive screw (10) and the connecting rod (14), thereby adjusting the position of the source furnace crucible (1) and making the source furnace crucible (1) concentric with the crucible plug.

2. The position adjustment mechanism of the high-temperature beam source furnace vacuum inner crucible according to claim 1, characterized in that: The axial section of the connecting rod (14) is in the shape of "cross", the horizontal side of the "cross" is located in the inside of the shell (12), the bellows (16) is located between the horizontal side of the "cross" and the flange (17), the other end of the bellows (16) is fixed on the horizontal side of the "cross", and the vertical side of the "cross" passes through the bellows (16).

3. The position adjustment mechanism of the high-temperature beam source furnace vacuum inner crucible according to claim 2, characterized in that: One end of the pointer screw (13) is fixed on the horizontal side of the "cross", the other end of the pointer screw (13) is extended out of the shell (12) through the strip-shaped hole (19) formed on the shell (12), and one side or both sides of the strip-shaped hole (19) is provided with a scale (20) along the moving direction of the connecting rod (14).

4. The position adjustment mechanism of the high-temperature beam source furnace vacuum inner crucible according to claim 1, wherein: The inside of the other end of the shell (12) is provided with a self-lubricating guide sleeve (11), the other end of the drive screw (10) is inserted into the guide sleeve (11), one end of the connecting rod (14) is provided with a threaded hole (21) along the axial direction, the other end of the drive screw (10) is threadedly connected with the threaded hole (21), and one end of the connecting rod (14) is extended into the space between the drive screw (10) and the self-lubricating guide sleeve (11).

5. The position adjustment mechanism of the high-temperature beam source furnace vacuum inner crucible according to claim 1, wherein: The power driving the rotation of the connecting rod (14) can be manual rotation of the shaft coupling (6) or driving through the shaft coupling (6) connected with a driving motor.

6. The position adjustment mechanism of the high-temperature beam source furnace vacuum inner crucible according to claim 1, wherein: The transmission assembly (5) is divided into a vacuum inner part and a vacuum outer part, and is separated by the bellows (16); rotating the shaft coupling (6) pushes the control fork (3) in the vacuum inner part to move in the radial direction of the vacuum outer source furnace cavity (2), thereby adjusting the position of the source furnace crucible (1).

7. The position adjustment mechanism of the high-temperature beam source furnace vacuum inner crucible according to claim 1, wherein: The transmission assembly (5) is two or more, and the transmission assembly (5) is located on the inclined side of the source furnace crucible (1) in the source furnace cavity (2), or each transmission assembly (5) is uniformly arranged in the circumferential direction.

Images