Method for purifying high-purity material
By converting solid or liquid materials into gaseous atoms or atomic clusters and using electric and magnetic fields to control ion movement and separate impurity ions, the problem of high purification cost of high-purity materials in existing technologies is solved, and efficient and low-cost preparation of high-purity materials is achieved.
Patent Information
- Application Number
- CN202410423970.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-09
- Publication Date
- 2025-10-14
AI Technical Summary
Existing high-purity material purification methods are difficult and costly when reaching 7N or 8N purity, and cannot meet the semiconductor industry's demand for material purity.
The solid or liquid material to be purified is converted into gaseous atoms or atomic clusters, and ionized to form charged ions. The electric and magnetic fields are used to control the movement of ions to separate the material ions and impurity ions. Finally, the material ions are deposited on the collector surface to obtain high-purity materials.
The process is simple, low-cost and has a purity of 7N or higher, making it suitable for scientific research and production.
Smart Images
Figure CN120776147A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a method for purifying high-purity materials, and belongs to the technical field of material purification. BACKGROUND
[0002] High-purity materials play an important role in many scientific research and production fields, especially in the semiconductor industry molecular beam epitaxy (MBE) equipment, which has very high requirements for material purity. Common high-purity materials can generally reach 4N (purity 99.99%) level, and can be prepared by using electrolytic refining method, crystallization method, directional solidification method, zone melting method, chemical method, high-temperature distillation method, or a combination of any one or more methods. The existing purification method can prepare 5N (purity 99.999%) or 6N (purity 99.9999%) level of ultra-high purity materials, but the cost is high, and the cost is very high. If the material purity continues to be improved to 7N (99.99999%) or 8N (99.999999%) level, the process difficulty is very high and the cost is expensive. Therefore, a new method is needed to solve the problems existing in the existing material purification method. SUMMARY
[0003] The main purpose of the present application is to provide a method for purifying high-purity materials, so as to overcome the shortcomings in the prior art.
[0004] In order to achieve the above-mentioned purpose of the application, the technical scheme adopted by the present application comprises:
[0005] The present application provides a method for purifying high-purity materials, comprising:
[0006] The solid or liquid material to be purified is converted into gaseous atoms or atomic clusters;
[0007] The gaseous atoms or atomic clusters are ionized into charged ions, the charged ions include material ions and impurity ions, and the charge-to-mass ratio of the material ions and the impurity ions is different;
[0008] A first electric field and a first magnetic field are applied to the charged ions to accelerate the movement speed of the charged ions to a first speed, and a plurality of charged ions are caused to move in a specified direction to form a collimated ion beam;
[0009] A second magnetic field is applied to the collimated ion beam to cause the impurity ions and the material ions with different charge-to-mass ratios in the ion beam to move in different motion radii and separate from each other;
[0010] A second electric field is applied to the ion beam separated from the impurity ions on the movement path of the ion beam to decelerate the movement speed of the ion beam to a second speed, the second speed is the average speed of thermal atomic motion, and the material ions in the ion beam are collected to obtain high-purity materials.
[0011] Compared with the prior art, the advantages of the present application include: the method for purifying high-purity materials provided by the present application has a simple process flow, lower cost, and the purity of the obtained materials can reach 7N, 8N or even higher, which has important significance in scientific research and production fields. BRIEF DESCRIPTION OF DRAWINGS
[0012] Figure 1 is a flowchart of a method for purifying high-purity materials provided in a typical embodiment of the present application;
[0013] Figure 2 is the motion trajectory of a charged ion in a vertically uniform second magnetic field. DETAILED DESCRIPTION
[0014] In view of the deficiencies in the prior art, the present inventors have obtained the technical solution of the present application through long-term research and a large number of practices. The technical solution, its implementation process and principles will be further explained as follows.
[0015] The present application provides a method for purifying high-purity materials, comprising:
[0016] Converting the solid or liquid material to be purified into gaseous atoms or atomic clusters;
[0017] Ionizing the gaseous atoms or atomic clusters into charged ions, the charged ions including material ions and impurity ions, the material ions and impurity ions having different charge-to-mass ratios;
[0018] Applying a first electric field and a first magnetic field to the charged ions to accelerate the motion speed of the charged ions to a first speed V1, and causing multiple charged ions to move in a specified direction to form a collimated ion beam,
[0019]
[0020] wherein U1 is the voltage of the first electric field (i.e. the acceleration voltage, the same below), and q / m is the reciprocal of the charge-to-mass ratio of the charged ions;
[0021] Applying a second magnetic field to the collimated ion beam to cause the impurity ions and material ions having different charge-to-mass ratios in the ion beam to move in different motion radius trajectories and separate from each other; the diameter D of the deflected motion trajectory of the charged ions in the second magnetic field satisfies:
[0022]
[0023] wherein U1 is the voltage of the first electric field, B is the magnetic field strength of the second magnetic field, and m / q is the mass-to-charge ratio of the charged ions;
[0024] A second electric field is applied on the moving path of the ion beam separated from the impurity ions to reduce the moving speed of the ion beam to a second speed, the second speed being the average speed of thermal atom movement, and collect the material ions in the ion beam to obtain high-purity material.
[0025] It can be understood that the moving direction of the charged ions generated after ionization is diffused in all directions, the first magnetic field can constrain the direction of the ions to make the moving direction of all the ions consistent, thereby forming a linear ion beam, the direction of the ion beam is towards the direction of the next mass spectrum separation region, and the second speed is less than the first speed and less than or equal to the moving speed before the charged ions are accelerated to the first speed.
[0026] Further, the voltage of the first electric field is 0.1 kV-1000 kV.
[0027] Further, the magnetic field strength of the first magnetic field is 0.001 T-3 T.
[0028] Further, the magnetic field strength of the second magnetic field is 0.01 T-3 T.
[0029] Further, the voltage of the second electric field is less than the voltage of the first electric field.
[0030] Further, the method for purifying high-purity material specifically comprises: converting the solid or liquid material into gaseous atoms or atomic clusters by at least one of the following ways: electric heating evaporation cracking, radio frequency heating evaporation cracking, laser pulse evaporation cracking, microwave heating evaporation cracking, and electric spraying.
[0031] Further, the method for purifying high-purity material specifically comprises: ionizing the gaseous atoms or atomic clusters into charged ions by at least one of the following ways: high-voltage electron beam bombardment, electron cyclotron resonance, electric arc discharge, high-frequency discharge, radio frequency ionization, microwave ionization, positive ion bombardment, atomic beam bombardment, chemical ionization, laser photoionization, and electric spraying ionization.
[0032] Further, the first electric field is used to accelerate the moving speed of the charged ions to a first speed, and the first magnetic field is used to constrain the moving track of the charged ions to form an ion beam moving along the specified direction.
[0033] Further, the moving directions of the plurality of charged ions are consistent.
[0034] Further, the specified direction is towards the direction of the next mass spectrum separation region.
[0035] Further, the second magnetic field is formed by an electromagnetic coil to form a stable magnetic field, and in order to separate the impurity ions, the current in the electromagnetic coil can be adjusted according to the mass-to-charge ratio of the selected material, so as to adjust the strength of the second magnetic field.
[0036] Further, the electric field direction of the second electric field is opposite to the electric field direction of the first electric field.
[0037] Further, the method for purifying high-purity materials specifically comprises: directly depositing the ion beam with the second speed on the conductive collector surface, and then neutralizing the material ions deposited on the collector surface, so as to obtain high-purity materials.
[0038] Further, the method for purifying high-purity materials specifically comprises: neutralizing the material ions in the ion beam with the second speed, and then collecting the neutralized material ions, so as to obtain high-purity materials.
[0039] Further, the method comprises: irradiating the ion beam with the second speed with an electron beam to neutralize the material ions in the ion beam.
[0040] Further, the purified solid or liquid material includes at least one of gallium, indium, aluminum, arsenic, phosphorus, bismuth, antimony, beryllium, and scandium, but is not limited thereto.
[0041] Further, the impurities include at least one of carbon, iron, aluminum, oxygen, sulfur, and silicon.
[0042] Further, the purity of the high-purity material obtained by the method is above 7N.
[0043] The technical solutions, implementation processes, and principles will be further explained in the following with reference to the accompanying drawings and specific implementation cases. Unless specifically stated, the equipment for converting solid or liquid materials into gaseous materials, the equipment for ionizing materials to form ions, and the electric field, the magnetic field, and the collector are known to those skilled in the art, and their specific models and structures are not limited herein.
[0044] In a more specific implementation case, the specific process and principles thereof will be described below by taking the purification of a gallium material containing iron impurities as an example.
[0045] Taking a gallium (Ga) metal material containing iron (Fe) impurities as an example, the method comprises:
[0046] Please refer to Figure 1 A method for purifying a gallium material containing iron impurities, comprising:
[0047] 1) The solid or liquid material to be purified is converted into gaseous atoms or atomic clusters by means of laser pulse evaporation cracking.
[0048] 2) The ionization of the gaseous atoms or atomic clusters into charged ions, including material ions and impurity ions, i.e. material ions-gallium ions (Ga 3+ ) and impurity ions-iron ions (Fe 3+ ) after ionization, is carried out by means of high-voltage electron beam bombardment, and the charge-to-mass ratio of the material ions and the impurity ions is different.
[0049] 3) A first electric field and a first magnetic field are applied to the charged ions, the first electric field is used to constrain the movement trajectory of the charged ions to form a collimated ion beam moving in a specified direction, and the first magnetic field is used to accelerate the movement speed of the charged ions to a first speed V1,
[0050]
[0051] wherein U1 is the voltage of the first electric field (i.e. the acceleration voltage, the same below), and q / m is the reciprocal of the charge-to-mass ratio of the charged ions.
[0052] Specifically, the first magnetic field is used to constrain the ion movement in a straight line direction, and the magnetic field strength of the first magnetic field is 0.001 T (unit: Tesla) to 3 T. In actual application, a uniform magnetic field consistent with the beam direction is usually applied on the beam pipe, if the movement direction of the charged particles is consistent with the direction of the beam pipe, the charged particles are not affected by the magnetic field, if the charged particles have a certain angle with the direction of the beam pipe, the movement component perpendicular to the direction of the beam pipe will be affected by the magnetic field to change the direction, and finally move along the helical shape of the beam pipe direction, so as to not touch the wall of the beam pipe. The strength of the first magnetic field determines the thickness of the beam helix. Another method of constraining ions is to use an electric field beam, and a positive voltage is applied on the beam pipe to make the beam pipe wall have the same charge as the material ions, and the same charge repulsion principle is used to make the ion beam constrained on the middle line of the beam pipe. For example, gallium ions have positive charge, a positive voltage is applied on the beam pipe to make the beam pipe wall have positive charge, if the material is arsenic, arsenic ions have negative charge, a negative voltage is applied on the beam pipe to make the beam pipe wall have negative charge, and the voltage is usually 0.1 kV (unit: kilovolt) to 200 kV. In actual application, the magnetic field beam and the electric field beam are usually combined to use, and the effect is better. The quality of the ion beam ultimately affects the efficiency and purity of the high-purity material collected at the end.
[0053] 4) A second magnetic field is applied to the collimated ion beam to make the impurity ions and the material ions with different charge-to-mass ratios in the ion beam move in different movement radius trajectories and separate from each other, and the diameter D of the deflected movement trajectory of the charged ions in the second magnetic field satisfies:
[0054]
[0055] Wherein, U1 is the voltage of the first electric field, B is the magnetic field intensity of the second magnetic field, and m / q is the mass-to-charge ratio of the charged ions.
[0056] Please refer to Figure 2 The trajectory of the charged ions in the second magnetic field is circular. Taking the material collection outlet at the end of the trajectory as an example, the charged ions are collected from Figure 2 As can be seen from formula 2), the material ions and the impurity ions are in the same acceleration voltage U1 (the voltage of the first electric field) and the same magnetic field intensity B (the magnetic field intensity of the second magnetic field), and due to the different mass-to-charge ratios m / q, the diameters D of the deflected trajectories of the charged ions in the second magnetic field are different, thereby realizing the separation of the impurity ions and the material ions.
[0057] It should be noted that, in theory, the diameter D of the deflected trajectory of the charged ions in the second magnetic field can be any value, as long as the values of the voltage U1 of the first electric field and the magnetic field intensity B of the second magnetic field satisfy formula 2) to realize the separation of the material ions and the impurity ions. In actual application, due to objective conditions, if the diameter D of the deflected trajectory of the charged ions in the second magnetic field is too small, the space is too small, which is not conducive to the installation and operation of the device. If the diameter D of the deflected trajectory of the charged ions in the second magnetic field is too large, the area of the second magnetic field will be very large, the space will be relatively large, and the cost will be relatively high. Therefore, the diameter D of the deflected trajectory of the charged ions in the second magnetic field is 0.1 meters to 100 meters.
[0058] Specifically, the magnetic field intensity B of the second magnetic field is 0.01 T (unit: Tesla) to 3 T. In actual application, the magnetic field intensity B of the second magnetic field is adjustable. After the value of the diameter D of the deflected trajectory of the charged ions in the second magnetic field is determined, it can be seen from formula 2) that when the value of the magnetic field intensity B of the second magnetic field is small, the acceleration voltage U1 will also be relatively small, and the cost will be relatively low.
[0059] Specifically, the voltage U1 of the first electric field is 0.1 kV (unit: kilovolt) to 1000 kV. In actual application, the voltage U1 of the first electric field is adjustable. The value of the voltage of the first electric field is reversely calculated according to the values of D and B determined in the previous two items. The value is the total value of the acceleration voltage. In actual application, there can be multiple low-voltage accelerations in series. For example, when a 2kV acceleration voltage is needed, a 2kV acceleration voltage device can be used to realize it, or two 1kV devices can be connected in series, or more low-voltage acceleration devices can be connected in series.
[0060] 5) A second electric field is applied on the motion path of the ion beam separated from the impurity ions, the direction of the second electric field is opposite to that of the first electric field, so as to slow down the motion speed of the ion beam to a second speed, and the second speed is the average speed of the thermal atom motion.
[0061] Specifically, the voltage of the second electric field (i.e. the deceleration voltage) is greater than 0 and less than the voltage of the first electric field, and the second electric field is used to reduce the speed of the ion beam to a state close to that before acceleration by the first electric field, so the value is less than the first electric field and the direction is opposite; if the voltage of the first electric field is small, the speed of the ion after acceleration is also not very large, then the second electric field is not needed, and the voltage of the first electric field is 134.46 kV, and the voltage of the second electric field is 130 kV.
[0062] 6) The ion beam is neutralized by an electron beam, and the ultra-high purity material is deposited on the surface of the collector.
[0063] Table 1 Ga 3+ Parameters after the first electric field, the first magnetic field and the second magnetic field
[0064]
[0065] Table 2 Ga 3+ , Fe 3+ Parameters after the first electric field, the first magnetic field and the second magnetic field
[0066]
[0067] From Table 1 and Table 2, it can be known that Ga 3+ , the magnetic field strength of the second magnetic field is selected as 0.5T, the acceleration voltage is calculated as 134.46kV, under the same first voltage and second magnetic field conditions, the impurity Fe 3+ The maximum diameter of the ion is 895mm, Fe 3+ and Ga 3+ are separated, Ga 3+ is collected at a track diameter of 1 meter, and high-purity materials are obtained.
[0068] Similarly, other impurity ions and Ga 3+ have different mass-to-charge ratios and different track diameters D, and can also be separated.
[0069] It should be understood that the above embodiments are only for illustrating the technical concepts and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made in accordance with the spirit and essence of the present application shall be covered within the protection scope of the present application.
Claims
1. A method for purifying high-purity materials, characterized in that: include: Converting the solid or liquid material to be purified into gaseous atoms or atomic clusters; Ionizing the gaseous atoms or atomic clusters into charged ions, wherein the charged ions include material ions and impurity ions, and the material ions and impurity ions have different charge-to-mass ratios; Applying a first electric field and a first magnetic field to the charged ions to accelerate the movement speed of the charged ions to a first speed V1, and making the multiple charged ions move along a specified direction to form a collimated ion beam, Where U1 is the voltage of the first electric field, q / m is the inverse mass-to-charge ratio of the charged ions; A second magnetic field is applied to the collimated ion beam so that impurity ions and material ions with different charge-to-mass ratios in the ion beam move along trajectories with different motion radii and separate from each other; the diameter D of the deflected motion trajectory of the charged ions in the second magnetic field satisfies: Where U1 is the voltage of the first electric field, B is the magnetic field strength of the second magnetic field, and m / q is the mass-to-charge ratio of the charged ions; A second electric field is applied to the movement path of the ion beam separated from the impurity ions to decelerate the movement speed of the ion beam to a second speed, which is the average speed of the movement of thermal atoms, and collect material ions in the ion beam to obtain high-purity material.
2. The method for purifying high-purity materials according to claim 1, characterized in that: Specifically include: Solid or liquid materials are converted into gaseous atoms or atomic clusters by at least one of electric heating evaporation and cracking, radio frequency heating evaporation and cracking, laser pulse evaporation and cracking, microwave heating evaporation and cracking, and electrospraying.
3. The method for purifying high-purity materials according to claim 1, characterized in that: Specifically include: The gaseous atoms or atomic clusters are ionized into charged ions by at least one of high-voltage electron beam bombardment, electron cyclotron resonance, arc discharge, high-frequency discharge, radio frequency ionization, microwave ionization, positive ion bombardment, atomic beam bombardment, chemical ionization, laser photoionization, and electrospray ionization.
4. The method for purifying high-purity materials according to claim 1, wherein: The first electric field is used to accelerate the movement speed of the charged ions to a first speed, and the first magnetic field is used to constrain the movement trajectory of the charged ions to form an ion beam moving along the specified direction.
5. The method for purifying high-purity materials according to claim 1 or 4, characterized in that: The movement directions of the plurality of charged ions are consistent; Preferably, the designated direction is the direction toward the next mass spectrometry separation area.
6. The method for purifying high-purity materials according to claim 1, characterized in that: The electric field direction of the second electric field is opposite to the electric field direction of the first electric field; Preferably, the voltage of the second electric field is smaller than the voltage of the first electric field; and / or, the voltage of the first electric field is 0.1 kV-1000 kV; And / or, the magnetic field strength of the first magnetic field is 0.001T-3T; And / or, the magnetic field strength of the second magnetic field is 0.01T-3T.
7. The method for purifying high-purity materials according to claim 1, characterized in that: Specifically include: The ion beam with the second velocity is directly incident on the conductive collector surface for deposition, and then the material ions deposited on the collector surface are neutralized to obtain high-purity material.
8. The method for purifying high-purity materials according to claim 1 or 7, characterized in that: Specifically include: First, the material ions in the ion beam having the second velocity are neutralized, and then the neutralized material ions are collected to obtain a high-purity material; Preferably, the method comprises: directing an electron beam toward an ion beam having a second velocity to neutralize material ions in the ion beam.
9. The method for purifying high-purity materials according to claim 1, characterized in that: The solid or liquid material to be purified includes at least one of gallium, indium, aluminum, arsenic, phosphorus, bismuth, antimony, beryllium, and scandium; preferably, the impurities include at least one of carbon, iron, aluminum, oxygen, sulfur, and silicon.
10. The method for purifying high-purity materials according to claim 1, characterized in that: The purity of the high-purity material obtained by the method is above 7N.