Ultra-large electron microscope vacuum system

Abstract

The invention provides a super-large electron microscope vacuum system, and belongs to the technical field of vacuum systems. The device comprises a vacuum sample bin, the portal frame is arranged in the vacuum sample bin; the electronic gun is arranged on the portal frame, and an objective lens is arranged at the bottom end; the sample storage and treatment platform is arranged in the vacuum sample bin; the electron gun can swing on the portal frame, and the sample storage processing platform can move in the vacuum sample bin. The invention relates to the technical field of vacuum systems.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum systems, and in particular to a super large electron microscope vacuum system. Background Art

[0002] For small samples, people stand still and the samples are moved to observe. For large samples, the samples are not moved and people move around the samples to observe. Existing electron microscopes usually have electron guns and objective lenses located on the top of the sample chamber and fixed. The samples are observed by moving the stage in the sample chamber. This can only observe flat samples, and the observation ability of curved samples is limited. Summary of the invention

[0003] In view of this, in order to solve the technical problem that the electron gun and objective lens of the existing electron microscope cannot be moved, resulting in the scanning electron microscope can only observe flat samples and the observation ability of curved samples is limited, the present invention provides an ultra-large electron microscope vacuum system, by placing the electron gun, objective lens, sample storage and processing platform, etc. in a vacuum sample chamber, sample observation is carried out, and the electron gun and objective lens are swung around the sample on the gantry to achieve the sample, The electron gun and objective lens can all be moved to observe the sample. In this way, the viewing of the sample surface will no longer be limited to the plane, and spherical samples and even wave surface samples can also be observed.

[0004] To achieve the above object, the present invention provides the following technical solutions: A super large electron microscope vacuum system, comprising: Vacuum sample chamber; A gantry is arranged in the vacuum sample chamber; A gantry is arranged in the vacuum sample chamber and has a Y-axis, a T-axis, a Z macro-motion axis and a Z micro-motion axis; The electron gun is arranged on the upper part of the gantry, and an objective lens is arranged at the bottom of the gantry. The electron gun can move forward and backward, up and down, and swing through the Y axis, T axis, Z macro axis, and Z micro axis of the gantry; The samples are stored on the sample storage and processing platform. The sample storage and processing platform has an X-axis and an R-axis, and the samples can be moved left and right and rotated through the X-axis and the R-axis.

[0005] Preferably, the vacuum system comprises a first-stage vacuum pumping system and a second-stage vacuum pumping system.

[0006] Preferably, the first-stage vacuum pumping system comprises a screw pump, a Roots pump, a third high vacuum gate valve and the vacuum sample chamber which are sequentially connected.

[0007] Preferably, the second-stage vacuum pumping system comprises a mechanical pump, a molecular pump, a high vacuum gate valve and the vacuum sample chamber which are connected in sequence.

[0008] Preferably, the second-stage vacuum pumping system is divided into two paths arranged in parallel.

[0009] Preferably, it also includes a vacuum breaking system; The vacuum breaking system comprises a nitrogen generator, a venting valve and the vacuum sample chamber which are connected in sequence.

[0010] Preferably, a Pirani vacuum gauge is provided on the vacuum sample chamber.

[0011] Preferably, a Penning gauge is provided on the vacuum sample chamber.

[0012] Preferably, an air pressure detection sensor is provided on the vacuum sample chamber.

[0013] Preferably, the vacuum sample chamber has a chamber door.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The ultra-large electron microscope vacuum system provided by the present invention places the electron gun, objective lens, sample storage and processing platform, etc. in a vacuum sample chamber to observe the sample. The electron gun and objective lens are swung around the sample on a gantry to achieve a movable way of observing the sample. In this way, the surface of the sample is no longer limited to a plane, and spherical samples and even wave surface samples can also be observed.

[0015] Placing both the electron gun and the objective lens in the vacuum sample chamber can solve the problem of vacuum leakage caused by the movement of the electron gun and objective lens in traditional electron microscopes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view of the present invention; In the figure, 1. molecular pump; 2. first high vacuum gate valve; 3. second high vacuum gate valve; 4. mechanical pump; 5. vent valve; 6. Pirani vacuum gauge; 7. Penning gauge; 8. third high vacuum gate valve; 9. air pressure detection sensor; 10. nitrogen generator; 11. Roots pump; 12. screw pump; 13. sample storage and processing platform; 14. vacuum sample chamber; 15. objective lens; 16. electron gun; 17. chamber door; 18. gantry. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0018] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0019] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] like Figure 1 As shown, the present invention provides a super large electron microscope vacuum system, comprising: Vacuum sample chamber 14; A gantry 18 is disposed in the vacuum sample chamber 14; The electron gun 16 is arranged on the gantry 18, and an objective lens 15 is arranged at the bottom end thereof; A sample storage and processing platform 13, which is disposed in the vacuum sample chamber 14; The electron gun 16 can swing on the gantry 18 , and the sample storage and processing platform 13 can move in the vacuum sample chamber 14 .

[0021] Gantry, with Y-axis, T-axis, Z macro-axis and Z micro-axis; The electron gun is arranged on the upper part of the gantry, and an objective lens is arranged at the bottom of the gantry. The electron gun can be moved forward and backward, up and down, and swung through the Y axis, T axis, Z macro axis, and Z micro axis of the gantry; The samples are stored on the sample storage and processing platform. The sample storage and processing platform has an X-axis and an R-axis, through which the samples can be moved left and right and rotated. The ultra-large electron microscope vacuum system provided by the present invention preferably adopts a six-axis motion platform, which includes: The X-axis linear motion structure is arranged on the base; A Y-axis linear motion mechanism is provided on the base and is used to provide the gantry 18 with movement along the Y direction; A Z-axis linear motion structure is disposed on the gantry 18; An R-axis rotation structure is disposed on the X-axis linear motion structure and is used to rotate the sample 360°; The T-axis tilting structure is arranged on the Z-axis linear motion structure to provide the electron gun 16 with a swing; The A-axis linear motion mechanism is disposed on the T-axis tilting structure, and is used to provide linear motion of the electron gun 16 along the A-axis direction.

[0022] A motor is installed on each axis, which is connected to a communication board, and the linkage between each axis is achieved through software control.

[0023] The six-axis motion platform can not only be used to place samples for observation, but also can be used in conjunction with other products such as heating platforms and in-situ stretching platforms to observe changes in samples under different conditions. When the samples are not being observed, a vacuum can be drawn to protect the samples from contamination and corrosion. Therefore, it is named the sample storage and processing platform.

[0024] The electron gun 16 can be moved by the six-axis motion platform. The sample is placed on the sample storage and processing platform 13, and the sample can rotate on the R-axis rotation structure and move along the X-direction on the X-axis linear motion structure.

[0025] In the present invention, the vacuum system includes a first-stage vacuum pumping system and a second-stage vacuum pumping system.

[0026] In the present invention, the first-stage vacuum pumping system includes a screw pump 12, a Roots pump 11, a third high vacuum gate valve 8 and the vacuum sample chamber 14 which are sequentially connected.

[0027] In the present invention, the second-stage vacuum pumping system includes a mechanical pump 4, a molecular pump 1, a high vacuum gate valve and the vacuum sample chamber 14 which are sequentially connected.

[0028] In the present invention, the second-stage vacuum pumping system is divided into two paths arranged in parallel.

[0029] In the present invention, a vacuum breaking system is also included; The vacuum breaking system includes a nitrogen generator 10, a venting valve 5 and the vacuum sample chamber 14 which are connected in sequence.

[0030] In the present invention, a Pirani vacuum gauge 6 is provided on the vacuum sample chamber 14. The Pirani vacuum gauge 6 is mainly used to measure the gas pressure in a vacuum environment, and is particularly suitable for measuring gas pressure in high and medium vacuum ranges. Its working principle is based on the Pirani principle, that is, the pressure value is calculated by measuring the resistance change of a metal wire of a certain length in a vacuum environment. The interior of the Pirani vacuum gauge 6 is usually made of tungsten wire or platinum-rhodium wire. The resistance of these metal wires will change with the change of gas pressure, thereby realizing the measurement of gas pressure. In the present invention, a Penning gauge 7 is provided on the vacuum sample chamber 14. The Penning gauge 7 is mainly used to measure the vacuum degree. It is a vacuum gauge made by utilizing the gas discharge phenomenon, and reflects the size of the vacuum degree by measuring the gas discharge current. The basic working principle of the Penning gauge 7 is to apply high voltage to the cathode metal ring, emit electrons in the anode tube, and these electrons rotate and disperse under the action of the magnetic field, and collide with gas molecules to generate ion current. The size of the ion current is proportional to the density of gas molecules and inversely proportional to the vacuum degree. After amplification, the vacuum value is displayed on the meter head.

[0031] The vacuum environment is generally divided into low vacuum, medium vacuum and high vacuum. Penning gauge 7 is suitable for high vacuum environment. When the vacuum value reaches the high vacuum stage, Penning gauge is used to detect the vacuum value. Pirani vacuum gauge 6 is suitable for medium vacuum environment. When the vacuum value reaches the medium vacuum stage, Pirani vacuum gauge is used to detect the vacuum value.

[0032] In the present invention, the vacuum sample chamber 14 is provided with an air pressure detection sensor 9. When the vacuum value is close to the atmospheric pressure, the Pirani gauge cannot display the vacuum value. At this time, the air pressure detection sensor is used to detect whether the vacuum value reaches the standard atmospheric pressure.

[0033] In the present invention, the vacuum sample chamber 14 has a chamber door 17 .

[0034] The working process of the present invention is as follows: The sample storage and processing platform 13 and the electron gun 16 are placed in a vacuum sample chamber 14 as a whole, and a vacuum environment is achieved by installing a molecular pump 1 on the top of the vacuum sample chamber 14 and connecting a Roots pump 11 on the side.

[0035] Start the vacuum: close the chamber door 17, open the first high vacuum gate valve 2, the second high vacuum gate valve 3, and the third high vacuum gate valve 8, start the screw pump 12, and perform rough vacuuming. After the vacuum value reaches 200 mbar, start the Roots pump 11. After the vacuum value reaches 4 mbar, open the mechanical pump 4, start the molecular pump 1, close the third high vacuum gate valve 8, close the Roots pump 11 and the screw pump 12, and continue to operate the electron microscope when the vacuum value reaches the standard.

[0036] Break the vacuum: Close the first high vacuum gate valve 2, the second high vacuum gate valve 3, the molecular pump 1, the mechanical pump 4, open the vent valve 5, wait until the vacuum value reaches atmospheric pressure, and then open the door to replace the sample.

[0037] The above are only preferred specific implementations of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vacuum system for an ultra-large electron microscope, characterized in that: include: Vacuum sample chamber; A gantry is arranged in the vacuum sample chamber and has a Y-axis, a T-axis, a Z macro-motion axis and a Z micro-motion axis; The electron gun is arranged on the upper part of the gantry, and an objective lens is arranged at the bottom of the gantry. The electron gun can move forward and backward, up and down, and swing through the Y axis, T axis, Z macro axis, and Z micro axis of the gantry; The samples are stored on the sample storage and processing platform. The sample storage and processing platform has an X-axis and an R-axis, and the samples can be moved left and right and rotated through the X-axis and the R-axis.

2. The ultra-large electron microscope vacuum system according to claim 1, characterized in that: The vacuum system comprises a first-stage vacuum pumping system and a second-stage vacuum pumping system.

3. The ultra-large electron microscope vacuum system according to claim 2, characterized in that: The first-stage vacuum pumping system includes a screw pump, a Roots pump, a third high vacuum gate valve and the vacuum sample chamber which are connected in sequence.

4. The ultra-large electron microscope vacuum system according to claim 2, characterized in that: The second-stage vacuum pumping system comprises a mechanical pump, a molecular pump, a high vacuum plug valve and the vacuum sample chamber which are connected in sequence.

5. The ultra-large electron microscope vacuum system according to claim 4, characterized in that: The second-stage vacuum pumping system is divided into two paths arranged in parallel.

6. The ultra-large electron microscope vacuum system according to claim 1, characterized in that: It also includes a vacuum breaking system; The vacuum breaking system comprises a nitrogen generator, a venting valve and the vacuum sample chamber which are connected in sequence.

7. The ultra-large electron microscope vacuum system according to claim 1, characterized in that: The vacuum sample chamber is provided with a Pirani vacuum gauge.

8. The ultra-large electron microscope vacuum system according to claim 1, characterized in that: The vacuum sample chamber is provided with a Penning gauge.

9. The ultra-large electron microscope vacuum system according to claim 1, characterized in that: The vacuum sample chamber is provided with an air pressure detection sensor.

10. A vacuum system for a very large electron microscope according to any one of claims 1 to 9, characterized in that: The vacuum sample chamber has a chamber door.

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