Preparation method and device of hydrofluoric acid for semiconductor

Abstract

The invention discloses a preparation method and device of hydrofluoric acid for a semiconductor, and belongs to the technical field of hydrofluoric acid preparation. The preparation method of hydrofluoric acid for semiconductors comprises the following steps: carrying out arsenic removal treatment on industrial anhydrous hydrogen fluoride to obtain primarily purified hydrogen fluoride; carrying out crude distillation on the arsenic-removed hydrogen fluoride, and separating low-boiling-point and high-boiling-point impurities to obtain hydrogen fluoride gas; the hydrogen fluoride gas is introduced into high-purity water for absorption, a hydrofluoric acid solution is obtained, the electrical resistivity of the high-purity water is larger than 18 M omega.cm, and the high-purity water is subjected to ion exchange and ultrafiltration pretreatment; rectifying the hydrofluoric acid solution to remove volatile impurities and heavy metal ions; the rectified hydrofluoric acid solution is filtered through a multi-stage filtering system, particulate matter and residual metal ions are removed, and the electronic-grade hydrofluoric acid is obtained.The preparation method and technology of the electronic-grade hydrofluoric acid are optimized, it is ensured that the quality of finished products meets the electronic-grade standard, and meanwhile the preparation efficiency of the finished products is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrofluoric acid preparation, and more specifically, to a preparation method and device for hydrofluoric acid for semiconductors. Background Art

[0002] Electronic-grade hydrofluoric acid is an indispensable key chemical in high-end electronic industries such as semiconductor manufacturing, photovoltaic material processing, and liquid crystal display panel production. Its main uses include silicon wafer cleaning, oxide layer etching, surface treatment, etc., and extremely strict requirements are imposed on the purity and impurity content of the product. Generally, the purity of electronic-grade hydrofluoric acid needs to reach more than 99.999%, the metal impurity content needs to be less than 1 ppb, and the particulate matter content also needs to be controlled at an extremely low level. Traditional hydrofluoric acid purification processes usually adopt a single distillation or filtration method, and it is difficult to remove volatile impurities, particulate matter, and metal ions simultaneously. Industrial anhydrous hydrogen fluoride often contains impurities such as arsenic, sulfur, and heavy metal ions, which will seriously affect the performance and yield of semiconductor devices. In view of this, we propose a preparation method and device for hydrofluoric acid for semiconductors. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method and device for hydrofluoric acid for semiconductors to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solutions: A preparation method for hydrofluoric acid for semiconductors, comprising the following steps: Subject industrial anhydrous hydrogen fluoride to arsenic removal treatment to obtain preliminarily purified hydrogen fluoride; Roughly distill the arsenic-removed hydrogen fluoride to separate low-boiling and high-boiling impurities to obtain hydrogen fluoride gas; Pass the hydrogen fluoride gas into high-purity water for absorption to obtain a hydrofluoric acid solution. The resistivity of the high-purity water is greater than 18 MΩ·cm, and it is pretreated by ion exchange and ultrafiltration; Rectify the hydrofluoric acid solution to remove volatile impurities and heavy metal ions; Filter the rectified hydrofluoric acid solution through a multi-stage filtration system to remove particulate matter and residual metal ions to obtain electronic-grade hydrofluoric acid.

[0005] Preferably, the arsenic removal treatment includes: Add an oxidant to industrial anhydrous hydrogen fluoride to oxidize the arsenide into an easily removable form; The oxidant is one or more of hydrogen peroxide, potassium permanganate, or ozone; The addition amount of the oxidant is 0.1%-1% of the mass of hydrogen fluoride.

[0006] Preferably, the rough distillation process includes: Separation is carried out in the rough distillation column, controlling the top temperature of the column to be 20 - 30 °C and the bottom temperature to be 40 - 60 °C; The rough distillation column is filled with high - efficiency packing, and condensers and reboilers are respectively provided at the top and bottom of the column.

[0007] Preferably, the rectification process includes: Separation is carried out in the rectification column, controlling the top temperature of the column to be 30 - 40 °C and the bottom temperature to be 60 - 80 °C; The rectification column is filled with high - efficiency fractionation packing, and condensers and reboilers are respectively provided at the top and bottom of the column.

[0008] A preparation device for hydrofluoric acid used in semiconductors, comprising: An arsenic - removal reactor for removing arsenic from industrial anhydrous hydrogen fluoride; A rough distillation column for separating low - boiling - point and high - boiling - point impurities in hydrogen fluoride gas; An absorption column for absorbing hydrogen fluoride gas into high - purity water; A rectification column for rectifying and purifying the hydrofluoric acid solution; A multi - stage filtration system for removing particulate matter and metal ions in the hydrofluoric acid solution; An oxidant addition device for adding an oxidant to hydrogen fluoride.

[0009] Preferably, the multi - stage filtration system includes a housing, a first filtration mechanism and a second filtration mechanism are arranged inside the housing. The first filtration mechanism includes a mounting shaft, a microporous filtration membrane assembly is arranged outside the mounting shaft. The microporous filtration membrane assembly includes multiple layers of microporous filtration membranes arranged obliquely. An installation column is arranged inside the housing, a spring is sleeved on the upper end of the installation column, the lower end of the spring is connected to the mounting shaft, the mounting shaft is in sliding fit with the installation column, and a shaking mechanism is arranged at the bottom of the installation column for making the mounting shaft reciprocate up and down.

[0010] Preferably, the second filtration mechanism is installed below the first filtration mechanism. The second filtration mechanism includes a filtration column, the inside of the filtration column is filled with ion - exchange resin, and the filtration column is arranged below the installation column.

[0011] Preferably, a microporous filtration disk is arranged below the microporous filtration membrane assembly; The shaking mechanism includes a driving component, a turntable is arranged above the driving component, a sloping plate is arranged on the turntable, a limiting shaft is arranged at the bottom of the microporous filtration disk, and the end of the limiting shaft is in sliding contact with the sloping plate; A fixed shaft is arranged at the lower end of the installation column, the turntable is rotatably connected to the fixed shaft, a toothed ring is arranged at the bottom of the turntable, a gear is arranged on the output shaft of the driving component, and the gear meshes with the toothed ring.

[0012] Preferably, a plurality of stirring plates are provided on the outer wall of the inclined plate. Installation holes are formed in the stirring plates, and a plurality of inclined blades arranged at equal intervals in a ring shape are provided in the installation holes. On opposite sides of the turntable, a first connecting seat and a positioning bolt are respectively provided. The upper end of the positioning bolt contacts the bottom surface of the inclined plate. A second connecting seat is provided on the bottom surface of the inclined plate, and the first connecting seat is rotatably connected to the second connecting seat.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention optimizes the preparation method and process of electronic-grade hydrofluoric acid. By using oxidants such as hydrogen peroxide and ozone, combined with optimized reaction conditions, high-efficiency removal of arsenides is achieved without introducing new impurities. Through a combined process of rough distillation, rectification, multi-stage filtration, and ion exchange, high-efficiency purification of hydrofluoric acid is realized. All devices are made of corrosion-resistant materials to ensure the long-term stable operation of the equipment in a strongly corrosive environment. An on-line monitoring system is introduced to monitor the purity and impurity content of hydrofluoric acid in real time to ensure that the quality of the finished product meets the electronic-grade standards.

[0014] (2) In the present invention, by providing multiple layers of inclined microporous filtration membranes, it is convenient for the hydrofluoric acid solution to flow through multiple microporous filtration membranes in sequence, enabling better filtration of the hydrofluoric acid solution. The microporous filtration membranes are inclined, facilitating the inclined movement of the filtered impurities to one side, avoiding blockage of the microporous filtration membranes, and prolonging the service life of the microporous filtration membranes. The jitter mechanism is used to move the installation shaft up and down reciprocally, thereby driving the microporous filtration membrane assembly to move up and down to form a jitter force, facilitating better filtration and flow of the hydrofluoric acid solution. Description of the Drawings

[0015] Figure 1 It is a flow chart of the preparation method of hydrofluoric acid for semiconductors of the present invention; Figure 2 It is a cross-sectional view of the multi-stage filtration system of the present invention; Figure 3 It is a side view of the multi-stage filtration system of the present invention; Figure 4 It is a structural diagram of the first filtration mechanism of the present invention; Figure 5 It is a structural diagram of the turntable and the inclined plate of the present invention.

[0016] Explanation of the reference numerals in the drawings: 1, housing; 2, first filtration mechanism; 201, installation shaft; 202, microporous filtration membrane assembly; 203, installation column; 204, microporous filtration disk; 3, second filtration mechanism; 4, drive assembly; 5, turntable; 501, first connecting seat; 502, positioning bolt; 6, inclined plate; 601, stirring plate; 602, inclined blade; 603, second connecting seat; 7, limiting shaft; 8, fixed shaft; 9, toothed ring; 10, gear. Detailed Embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0018] Embodiment: Please refer to Figures 1-5 , a preparation device for hydrofluoric acid used in semiconductors, including an arsenic removal reactor for removing arsenic from industrial anhydrous hydrogen fluoride; a rough distillation column for separating low-boiling and high-boiling impurities in hydrogen fluoride gas; an absorption column for introducing hydrogen fluoride gas into high-purity water for absorption; a rectification column for rectifying and purifying the hydrofluoric acid solution; a multi-stage filtration system for removing particulate matter and metal ions in the hydrofluoric acid solution; an oxidant addition device for adding an oxidant to hydrogen fluoride, and the oxidant addition device is installed on the arsenic removal reactor. Among them, the arsenic removal reactor, the rough distillation column, the absorption column, the rectification column, and the multi-stage filtration system are sequentially connected through a delivery pipe. After the arsenic removal treatment of anhydrous hydrogen fluoride, it enters the rough distillation column to separate low-boiling and high-boiling impurities in the hydrogen fluoride gas. The hydrogen fluoride gas after separating the impurities enters the absorption column and is absorbed using high-purity water. Then, a hydrofluoric acid solution is obtained. The hydrofluoric acid solution is transported to the rectification column for rectifying and purifying the hydrofluoric acid solution, and then transported to the multi-stage filtration system to remove particulate matter and metal ions in the hydrofluoric acid solution, obtaining an electronic-grade hydrofluoric acid solution.

[0019] Among them, oxidants such as hydrogen peroxide and ozone are used, combined with optimized reaction conditions, to achieve efficient removal of arsenides without introducing new impurities. Through a combined process of rough distillation, rectification, multi-stage filtration, and ion exchange, efficient purification of hydrofluoric acid is achieved. Each device uses corrosion-resistant materials to ensure the long-term stable operation of the equipment in a strongly corrosive environment. An online monitoring system is introduced to monitor the purity and impurity content of hydrofluoric acid in real time to ensure that the finished product quality meets the electronic-grade standard.

[0020] In this application, the multi-stage filtration system includes a housing 1. Inside the housing 1, a first filtration mechanism 2 and a second filtration mechanism 3 are provided. The first filtration mechanism 2 includes a mounting shaft 201. Outside the mounting shaft 201, a microporous filtration membrane assembly 202 is provided. The microporous filtration membrane assembly 202 includes multiple layers of microporous filtration membranes arranged obliquely, which facilitates the hydrofluoric acid solution to flow through multiple microporous filtration membranes in sequence, enabling better filtration of the hydrofluoric acid solution. The microporous filtration membranes are arranged obliquely, which is convenient for the impurities to be filtered to incline to one side, avoiding blockage of the microporous filtration membranes and increasing the service life of the microporous filtration membranes. Inside the housing 1, a mounting post 203 is provided. A spring is sleeved on the upper end of the mounting post 203. The lower end of the spring is connected to the mounting shaft 201. The mounting shaft 201 is slidably matched with the mounting post 203. A shaking mechanism is provided at the bottom of the mounting post 203. The shaking mechanism is used to move the mounting shaft 201 up and down reciprocally, thereby driving the microporous filtration membrane assembly 202 to move up and down to form a shaking force, facilitating better filtration and flow of the hydrofluoric acid solution. The setting of the spring facilitates pulling the mounting post 203 to move upward. When the mounting shaft 201 moves downward, the spring will be stretched.

[0021] In this application, the second filtration mechanism 3 is installed below the first filtration mechanism 2. The second filtration mechanism 3 includes a filtration column filled with ion exchange resin inside. The filtration column is arranged below the mounting post 203. The hydrofluoric acid solution removes particulate matter through the first filtration mechanism 2 and then removes residual metal ions through the second filtration mechanism 3.

[0022] In this application, a microporous filtration disk 204 is provided below the microporous filtration membrane assembly 202, and the microporous filtration disk 204 is horizontally arranged; the shaking mechanism includes a driving component 4. Above the driving component 4, a turntable 5 is provided. An inclined plate 6 is provided on the turntable 5. A limiting shaft 7 is provided at the bottom of the microporous filtration disk 204, and the end of the limiting shaft 7 is in sliding contact with the inclined plate 6; by driving the driving component 4 to drive the turntable 5 and the inclined plate 6 to rotate, since the inclined plate 6 is arranged obliquely, it will contact the limiting shaft 7 during rotation, thereby jacking up the limiting shaft 7, and thus jacking up the microporous filtration disk 204 and the microporous filtration membrane assembly 202. At this time, the spring is compressed. When the inclined plate 6 rotates to Figure 3 the initial position shown, the spring will push the mounting shaft 201 and the microporous filtration disk 204 to move downward under the action of the restoring elastic force. In this way, reciprocating motion is achieved, thereby realizing the up and down reciprocating motion of the microporous filtration membrane assembly 202 and the microporous filtration disk 204, improving the filtration efficiency of impurities, and at the same time preventing blockage of the microporous filtration membrane assembly 202 and the microporous filtration disk 204.

[0023] A fixed shaft 8 is provided at the lower end of the mounting post 203. The turntable 5 is rotatably connected to the fixed shaft 8. A toothed ring 9 is provided at the bottom of the turntable 5. A gear 10 is provided on the output shaft of the driving component 4, and the gear 10 meshes with the toothed ring 9. The driving component 4 drives the gear 10 and the toothed ring 9 to rotate, thereby driving the turntable 5 to rotate.

[0024] In this application, a plurality of stirring plates 601 are arranged on the outer wall of the inclined plate 6. Installation holes are formed in the stirring plates 601, and a plurality of inclined blades 602 arranged at equal intervals in a ring shape are arranged in the installation holes. Through the arrangement of the stirring plates 601, when the inclined plate 6 rotates, the stirring plates 601 will rotate along with it, so that the solution between the microporous filter disc 204 and the second filtering mechanism 3 flows to form a backwashing effect, which can further prevent the microporous filter disc 204 from being blocked. At the same time, it will also increase the speed of the solution entering the second filtering mechanism 3 below, improving the filtering effect of hydrofluoric acid.

[0025] Among them, a first connecting seat 501 and a positioning bolt 502 are respectively arranged on opposite sides of the turntable 5. The upper end of the positioning bolt 502 contacts the bottom surface of the inclined plate 6. The positioning bolt 502 is threadedly connected to the turntable 5. A second connecting seat 603 is arranged on the bottom surface of the inclined plate 6. The first connecting seat 501 is rotatably connected to the second connecting seat 603. By adjusting the height of the positioning bolt 502 extending out of the turntable 5, the inclination angle of the inclined plate 6 can be changed and adjusted as needed.

[0026] A preparation method of hydrofluoric acid for semiconductors includes the following steps: Step 1: Subject industrial anhydrous hydrogen fluoride to arsenic removal treatment to obtain preliminarily purified hydrogen fluoride. Specifically, the arsenic removal treatment includes: adding an oxidant to industrial anhydrous hydrogen fluoride to oxidize arsenides into forms that are easy to remove; the oxidant is one or more of hydrogen peroxide, potassium permanganate or ozone; the addition amount of the oxidant is 0.1%-1% of the mass of hydrogen fluoride.

[0027] Step 2: Crudely distill the arsenic-removed hydrogen fluoride to separate low-boiling and high-boiling impurities to obtain hydrogen fluoride gas. The specific crude distillation process includes: separating in a crude distillation column, controlling the top temperature of the column to be 20-30°C and the bottom temperature of the column to be 40-60°C; the crude distillation column is filled with high-efficiency packing, and condensers and reboilers are respectively arranged at the top and bottom of the column.

[0028] Step 3: Pass the hydrogen fluoride gas into high-purity water for absorption to obtain a hydrofluoric acid solution. The resistivity of the high-purity water is greater than 18 MΩ·cm, and it is pretreated by ion exchange and ultrafiltration. Step 4: Rectify the hydrofluoric acid solution to remove volatile impurities and heavy metal ions. Specifically, the rectification process includes: separating in a rectification column, controlling the top temperature of the column to be 30-40°C and the bottom temperature of the column to be 60-80°C; the rectification column is filled with high-efficiency fractionating packing, and condensers and reboilers are respectively arranged at the top and bottom of the column.

[0029] Step 5: Filter the rectified hydrofluoric acid solution through a multi-stage filtration system to remove particulate matter and residual metal ions to obtain electronic-grade hydrofluoric acid.

[0030] Example 1: Arsenic removal treatment: Take 1000 kg of industrial anhydrous hydrogen fluoride, add hydrogen peroxide (the addition amount is 0.1% of the mass of hydrogen fluoride, that is, 1 kg) as an oxidant thereto, and fully stir and react in an arsenic removal reactor for 2 hours to oxidize the arsenide into a form that is easy to remove, obtaining preliminarily purified hydrogen fluoride.

[0031] Crude distillation: Transfer the arsenic-removed hydrogen fluoride to a crude distillation column. The crude distillation column is filled with high-efficiency packing, and a condenser and a reboiler are respectively provided at the top and bottom of the column. Control the top temperature at 20 °C and the bottom temperature at 40 °C to separate low-boiling and high-boiling impurities, obtaining hydrogen fluoride gas.

[0032] Absorption: Pass the obtained hydrogen fluoride gas into high-purity water that has been pretreated by ion exchange and ultrafiltration and has a resistivity greater than 18 MΩ·cm for absorption to obtain a hydrofluoric acid solution in an absorption column.

[0033] Rectification: Transfer the hydrofluoric acid solution to a rectification column. The rectification column is filled with high-efficiency fractionation packing, and a condenser and a reboiler are respectively provided at the top and bottom of the column. Control the top temperature at 30 °C and the bottom temperature at 60 °C to remove volatile impurities and heavy metal ions.

[0034] Filtration: Pass the rectified hydrofluoric acid solution through a multi-stage filtration system in sequence. First, pass through a pre-filter to remove large-particle impurities, then pass through a micro-filter to remove fine particulate matters, then pass through an ion exchange column to remove metal ions, and finally pass through a terminal filter to ensure that the final product has no particulate matters, obtaining electronic-grade hydrofluoric acid.

[0035] Example 2: Arsenic removal treatment: Weigh 1500 kg of industrial anhydrous hydrogen fluoride, add potassium permanganate (the addition amount is 0.5% of the mass of hydrogen fluoride, that is, 7.5 kg) as an oxidant thereto, and stir and react in an arsenic removal reactor for 3 hours to oxidize the arsenide, obtaining preliminarily purified hydrogen fluoride.

[0036] Crude distillation: Feed the preliminarily purified hydrogen fluoride into a crude distillation column. The crude distillation column is filled with high-efficiency packing, and a condenser and a reboiler are respectively provided at the top and bottom of the column. Control the top temperature at 25 °C and the bottom temperature at 50 °C for crude distillation to separate low-boiling and high-boiling impurities, obtaining hydrogen fluoride gas.

[0037] Absorption: Pass the hydrogen fluoride gas into pretreated high-purity water (resistivity greater than 18 MΩ·cm) to obtain a hydrofluoric acid solution in an absorption column.

[0038] Rectification: Transfer the hydrofluoric acid solution to a rectification column filled with high-efficiency fractionation packing. A condenser and a reboiler are respectively installed at the top and bottom of the rectification column. Control the top temperature at 35°C and the bottom temperature at 70°C for rectification to remove volatile impurities and heavy metal ions.

[0039] Filtration: Pass the rectified hydrofluoric acid solution through a multi-stage filtration system. The pre-filter removes large particle impurities, the micro-filter removes tiny particles, the ion exchange column removes metal ions, and the terminal filter ensures that the final product is free of particles. The filters and pipes of the multi-stage filtration system are made of quartz, and finally, electronic-grade hydrofluoric acid is obtained.

[0040] Example 3: Arsenic removal treatment: Take 2000 kg of industrial anhydrous hydrogen fluoride, and simultaneously add hydrogen peroxide (the addition amount is 0.3% of the mass of hydrogen fluoride, i.e., 6 kg) and ozone (the input amount is controlled according to the reaction situation) as oxidants, and react in an arsenic removal reactor for 2.5 hours to oxidize the arsenide to obtain preliminarily purified hydrogen fluoride.

[0041] Crude distillation: Place the preliminarily purified hydrogen fluoride in a crude distillation column filled with high-efficiency packing. A condenser and a reboiler are respectively installed at the top and bottom of the crude distillation column. Control the top temperature at 30°C and the bottom temperature at 60°C for crude distillation operation to obtain hydrogen fluoride gas.

[0042] Absorption: Pass the hydrogen fluoride gas into pretreated high-purity water (resistivity greater than 18 MΩ・cm) to obtain a hydrofluoric acid solution in an absorption column.

[0043] Rectification: Transfer the hydrofluoric acid solution to a rectification column filled with high-efficiency fractionation packing. A condenser and a reboiler are respectively installed at the top and bottom of the rectification column. Control the top temperature at 40°C and the bottom temperature at 80°C for rectification to remove volatile impurities and heavy metal ions.

[0044] Filtration: Pass the rectified hydrofluoric acid solution through a multi-stage filtration system. The pre-filter removes large particle impurities, the micro-filter removes tiny particles, the ion exchange column removes metal ions, and the terminal filter ensures that the final product is free of particles. The filters and pipes of the multi-stage filtration system are made of Hastelloy to obtain electronic-grade hydrofluoric acid.

[0045] Quality detection of electronic-grade hydrofluoric acid: Purity detection: Use ion chromatography (IC) to detect anionic impurities (such as Cl - , SO 4 ² - etc.) in hydrofluoric acid.

[0046] Metal impurity detection: Use inductively coupled plasma mass spectrometry (ICP-MS) to detect metal ions (such as Na+ , K + , Fe³ + , etc.).

[0047] Particle detection: A laser particle counter is used to detect the particles in hydrofluoric acid.

[0048] Table 1, Quality inspection results of the electronic-grade hydrofluoric acid obtained in Example 1, Example 2, and Example 3: Through the above examples, the preparation method, device structure, process optimization, quality inspection, and specific applications of electronic-grade hydrofluoric acid are described in detail, fully demonstrating the feasibility and practicality of the method.

[0049] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing hydrofluoric acid for semiconductor use, characterized in that: The steps include: The industrial anhydrous hydrogen fluoride is subjected to arsenic removal treatment to obtain preliminarily purified hydrogen fluoride; The hydrogen fluoride after arsenic removal is crudely distilled to separate low-boiling point and high-boiling point impurities to obtain hydrogen fluoride gas; Passing the hydrogen fluoride gas into high-purity water for absorption to obtain a hydrofluoric acid solution, wherein the high-purity water has a resistivity greater than 18 MΩ·cm and is pre-treated by ion exchange and ultrafiltration; distilling the hydrofluoric acid solution to remove volatile impurities and heavy metal ions; The rectified hydrofluoric acid solution is filtered through a multi-stage filtration system to remove particulate matter and residual metal ions to obtain electronic grade hydrofluoric acid.

2. The method for preparing hydrofluoric acid for semiconductor according to claim 1, characterized in that: The arsenic removal treatment comprises: Add an oxidant to industrial anhydrous hydrogen fluoride to oxidize the arsenic compound into a form that is easier to remove; The oxidant is one or more of hydrogen peroxide, potassium permanganate or ozone; The amount of the oxidant added is 0.1%-1% of the mass of hydrogen fluoride.

3. The method for preparing hydrofluoric acid for semiconductor according to claim 1, characterized in that: The crude distillation process comprises: Separation is carried out in a crude distillation tower, with the top temperature of the tower controlled at 20-30°C and the bottom temperature of the tower controlled at 40-60°C; The crude distillation tower is filled with high-efficiency packing, and a condenser and a reboiler are provided at the top and bottom of the tower respectively.

4. The method for preparing hydrofluoric acid for semiconductor according to claim 1, characterized in that: The distillation process comprises: Separation is carried out in a distillation tower, with the top temperature controlled at 30-40°C and the bottom temperature at 60-80°C; The distillation tower is filled with high-efficiency fractionation fillers, and a condenser and a reboiler are respectively provided at the top and bottom of the tower.

5. A device for preparing hydrofluoric acid for semiconductors, applied to the method according to any one of claims 1 to 4, characterized in that: include: Arsenic removal reactor, used for removing arsenic from industrial anhydrous hydrogen fluoride; A crude distillation tower is used to separate low-boiling-point and high-boiling-point impurities in hydrogen fluoride gas; An absorption tower is used to pass hydrogen fluoride gas into high-purity water for absorption; A distillation tower, used for distilling and purifying the hydrofluoric acid solution; Multi-stage filtration system to remove particulate matter and metal ions from hydrofluoric acid solution; The oxidant adding device is used for adding oxidant into hydrogen fluoride.

6. The device for preparing hydrofluoric acid for semiconductor according to claim 5, characterized in that: The multi-stage filtration system comprises a housing (1), wherein a first filtration mechanism (2) and a second filtration mechanism (3) are arranged in the housing (1), wherein the first filtration mechanism (2) comprises a mounting shaft (201), wherein a microporous filtration membrane assembly (202) is arranged outside the mounting shaft (201), wherein the microporous filtration membrane assembly (202) comprises multiple layers of microporous filtration membranes arranged obliquely, wherein a mounting column (203) is arranged in the housing (1), wherein a spring is sleeved on the upper end of the mounting column (203), wherein the lower end of the spring is connected to the mounting shaft (201), wherein the mounting shaft (201) and the mounting column (203) are slidably matched, and wherein a shaking mechanism is arranged at the bottom of the mounting column (203), wherein the shaking mechanism is used to cause the mounting shaft (201) to reciprocate up and down.

7. The device for preparing hydrofluoric acid for semiconductor according to claim 6, characterized in that: The second filtering mechanism (3) is installed below the first filtering mechanism (2), the second filtering mechanism (3) comprises a filtering column, the interior of the filtering column is filled with ion exchange resin, and the filtering column is arranged below the mounting column (203).

8. The device for preparing hydrofluoric acid for semiconductor according to claim 6, characterized in that: A microporous filter disc (204) is disposed below the microporous filter membrane assembly (202); The shaking mechanism comprises a driving assembly (4), a rotating disk (5) is arranged above the driving assembly (4), an inclined plate (6) is arranged on the rotating disk (5), a limiting shaft (7) is arranged at the bottom of the microporous filter disc (204), and an end of the limiting shaft (7) is in sliding contact with the inclined plate (6); A fixed shaft (8) is disposed at the lower end of the mounting column (203), the turntable (5) is rotatably connected to the fixed shaft (8), a gear ring (9) is disposed at the bottom of the turntable (5), a gear (10) is disposed on the output shaft of the drive assembly (4), and the gear (10) is meshed with the gear ring (9).

9. The device for preparing hydrofluoric acid for semiconductor according to claim 8, characterized in that: The outer wall of the inclined plate (6) is provided with a plurality of stirring plates (601), the stirring plates (601) are provided with mounting holes, and the mounting holes are provided with a plurality of inclined blades (602) arranged in a ring shape and at equal intervals; A first connecting seat (501) and a positioning bolt (502) are respectively provided on opposite sides of the rotating disk (5); the upper end of the positioning bolt (502) contacts the bottom surface of the inclined plate (6); a second connecting seat (603) is provided on the bottom surface of the inclined plate (6); and the first connecting seat (501) is rotatably connected to the second connecting seat (603).

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