Method for reducing hydrogen fluoride in germanium tetrafluoride

Abstract

The invention belongs to the technical field of gas purification, and particularly relates to a method for reducing hydrogen fluoride in germanium tetrafluoride. The method comprises the steps that S1, a reactor filled with germanium oxide and activated carbon mixed filler is purged with hydrogen, the hydrogen and germanium oxide are subjected to an oxidation-reduction reaction, and germanium oxide is reduced into metal germanium; s2, purging the reduced mixed filler in the reactor with nitrogen, and vacuumizing the reactor; and S3, introducing a hydrogen fluoride-containing germanium tetrafluoride raw material into the mixed filler in the step S2, reacting hydrogen fluoride in the raw material germanium tetrafluoride with germanium, converting into germanium tetrafluoride, and collecting the germanium tetrafluoride. The method is simple in process and capable of realizing large-scale production, realizes efficient removal of HF in germanium tetrafluoride, has high purity, low cost and environmental friendliness, and meets the production requirements of semiconductor-grade GeF4.

Description

Technical Field

[0001] This application belongs to the field of gas purification, and particularly relates to a method for reducing hydrogen fluoride in germanium tetrafluoride. Background Art

[0002] Germanium tetrafluoride (GeF4) is used for doping and ion implantation in the semiconductor industry. It is an important semiconductor material and can be used to fabricate optoelectronic devices and electronic components. Combined with disilane gas, silicon-germanium microcrystals can be directly fabricated on a glass substrate, and its potential application value has attracted increasing attention from domestic and foreign enterprises. Due to its excellent electrical and optical properties, it is widely used in fields such as solar cells, photoelectric sensors, frequency doublers, and electronic isolators. It is a multifunctional compound with broad application prospects. It has important uses in electronic materials, chemical catalysts, metal coating materials, gas sensors, optical coating materials, and biomedical materials, and is of great significance for improving the level of science and technology and the quality of life.

[0003] In the process of fabricating microelectronic and optoelectronic devices, from the individual generation to the final device assembly, almost every step and every link cannot do without electronic gases. The quality of electronic gases also determines the quality of semiconductor devices. For every improvement in the purity of electronic gases, the quality of semiconductor devices will experience a leap. Even for market-high-purity germanium tetrafluoride, the content of hydrogen fluoride in it is relatively high.

[0004] The presence of hydrogen fluoride in germanium tetrafluoride will cause various defects in the application of germanium tetrafluoride, which are mainly reflected in the following aspects:

[0005] ① Corrosion problems. For example, in the semiconductor manufacturing process, hydrogen fluoride may corrode the electrodes and other key components of ion implantation equipment, resulting in equipment damage and shortened service life. Hydrogen fluoride will also react with materials such as glass. Although dry germanium tetrafluoride itself does not corrode glass, the presence of HF will destroy this stability.

[0006] ② Influence on semiconductor processes. In semiconductor manufacturing, germanium tetrafluoride is often used in processes such as doping and ion implantation. However, the presence of hydrogen fluoride will lead to uneven impurity doping, affecting the performance and reliability of semiconductor devices. HF may also react with other components in the semiconductor material to generate undesired by-products, such as reacting with germanium dioxide to generate germanium tetrafluoride and water, which will interfere with the normal chemical reaction process.

[0007] ③ Influence on thin film materials. Germanium tetrafluoride is often used as a precursor for gas conversion thin film materials in the electronics industry. The presence of HF may cause changes in the chemical composition and structure of the thin film, affecting the optical and electrical properties of the thin film.

[0008] At present, most of the methods for reducing hydrogen fluoride in germanium tetrafluoride use sodium fluoride for adsorption, which may result in the loss of germanium tetrafluoride. This not only reduces the yield of the refined product, but also the hydrogen fluoride content in the final refined germanium tetrafluoride is relatively high. For example, in the application with the application number CN202411761082.1, a purification device and method for germanium tetrafluoride are disclosed, which use sodium fluoride or potassium fluoride to absorb hydrogen fluoride.

[0009] In summary, it is difficult to effectively remove hydrogen fluoride in germanium tetrafluoride in the existing germanium tetrafluoride purification technology. Therefore, there is an urgent need to propose a method that can effectively remove hydrogen fluoride in germanium tetrafluoride to solve the problems existing in the prior art. Summary of the Invention

[0010] Aiming at the difficulty in effectively removing hydrogen fluoride in germanium tetrafluoride in the existing purification technology, this application proposes a method to significantly reduce the hydrogen fluoride content in germanium tetrafluoride and improve the utilization rate of germanium tetrafluoride raw materials.

[0011] The specific solution of this application is as follows:

[0012] A method for reducing hydrogen fluoride in germanium tetrafluoride, comprising the following steps:

[0013] Step S1. Purge the reactor filled with a mixed filler of germanium oxide and activated carbon with hydrogen. An oxidation-reduction reaction occurs between hydrogen and germanium oxide, and germanium oxide is reduced to metallic germanium to obtain a reduced mixed raw material.

[0014] Step S2. First, purge the reduced mixed filler in the reactor with nitrogen, and then evacuate the reactor.

[0015] Step S3. Introduce the germanium tetrafluoride raw material containing hydrogen fluoride into the mixed filler in Step S2. The hydrogen fluoride in the raw material germanium tetrafluoride reacts with germanium, is converted into germanium tetrafluoride and collected.

[0016] Preferably, the mass ratio of germanium oxide to activated carbon in the mixed filler of germanium oxide and activated carbon in Step S1 is 1:(3 - 5).

[0017] Preferably, the temperature of the oxidation-reduction in Step S1 is 100°C - 200°C, the flow rate of hydrogen is 20 mL / min - 150 mL / min, and the purging time is 12 h - 24 h.

[0018] Preferably, the flow rate of nitrogen in Step S2 is 20 mL / min - 150 mL / min, the purging time is 12 h - 24 h, and the temperature of the reactor is controlled at 100°C - 200°C.

[0019] Preferably, in Step S2, the reactor is evacuated to a vacuum degree of -0.1 Mpa.

[0020] Preferably, in step S3, the purity of the raw material germanium tetrafluoride is 99.99%, and the flow rate is 0.5 L / min to 1.5 L / min.

[0021] Preferably, in step S3, the reaction temperature is 150°C to 200°C, and the pressure is 0.10 Mpa to 0.5 Mpa.

[0022] Preferably, the purity of hydrogen in step S1 is ≥99.99%.

[0023] Preferably, the purity of nitrogen in step S2 is ≥99.99%.

[0024] The beneficial effects of this application are as follows:

[0025] (1) High-efficiency removal of hydrogen fluoride (HF): Through the mixed filler formed by loading germanium oxide on activated carbon, highly reactive metallic germanium is generated after hydrogen reduction, which reacts with HF in germanium tetrafluoride (GeF4) (Ge + 4HF → GeF4 + 2H2↑), directly converting it into the target product GeF4 and reducing the content of HF impurities.

[0026] (2) This application selects activated carbon as the carrier: It not only ensures the uniform loading of germanium oxide on the carrier but also provides an abundant pore structure, improving the efficiency of the reduction reaction and subsequent HF adsorption-conversion.

[0027] (3) Dual purification guarantee system: Hydrogen purging combined with nitrogen purging and vacuum treatment thoroughly removes moisture and residual gases in the reaction system, avoids impurity interference, and ensures a highly clean reaction environment. In summary, the process of this application is simple and scalable, achieving high-efficiency removal of HF in germanium tetrafluoride, while also having low cost and environmental friendliness, meeting the production requirements of semiconductor-grade GeF4. Detailed implementation manners

[0028] To further elaborate on the technical means and effects adopted by this application to achieve the predetermined invention purpose, the following combines preferred embodiments to detail the specific implementation manners, structures, features, and their effects according to this application. It should be noted that the two substances in the germanium oxide and activated carbon mixed filler of this application are mixed by mechanical stirring.

[0029] Example 1

[0030] This example provides a method for reducing hydrogen fluoride in germanium tetrafluoride, which is as follows:

[0031] Step S1. Hydrogen (with a purity of 99.99%) is introduced into the mixed filler of germanium oxide and activated carbon (the mass ratio of germanium oxide to activated carbon is 1:4). The hydrogen reduces germanium oxide to metallic germanium. The temperature is controlled at 150°C, the gas flow rate of hydrogen is controlled at 100 mL / min, and the purging time is 18 h to ensure that all germanium oxide is reduced to metallic germanium.

[0032] Step S2. First, the reactor is purged with nitrogen (with a purity of 99.99%), and then the reactor is vacuum-treated with a vacuum pump to a vacuum of -0.1 Mpa. The nitrogen flow rate is controlled at 100 mL / min, the temperature of the reactor is controlled at 150°C, and the nitrogen purging time is 18 h.

[0033] By adopting the above technical solution, nitrogen purging can remove the impurity gases generated during the reduction process, and vacuum treatment can further remove the residual gases in the filler to ensure the purity of the filler and the stability of the reaction environment.

[0034] Step S3. Germanium tetrafluoride (with a purity of 99.99%) as the raw material is introduced into the mixed filler in Step S2. The temperature is controlled at 180°C, the pressure is 0.3 Mpa, and the gas flow rate for introduction is 1.0 L / min. The hydrogen fluoride in the raw material reacts with germanium to be converted into germanium tetrafluoride.

[0035] Example 2

[0036] Step S1. Hydrogen (with a purity of 99.998%) is introduced into the mixed filler of germanium oxide and activated carbon (the mass ratio of germanium oxide to activated carbon is 1:3). The temperature is controlled at 200°C, the gas flow rate of hydrogen is controlled at 20 mL / min, and the purging time is 24 h.

[0037] Step S2. First, the reactor is purged with nitrogen (with a purity of 99.994%), and then the reactor is vacuum-treated with a vacuum pump to a vacuum of -0.1 Mpa. The nitrogen flow rate is controlled at 20 mL / min, the temperature of the reactor is controlled at 200°C, and the nitrogen purging time is 12 h.

[0038] Step S3. Germanium tetrafluoride (with a purity of 99.99%) as the raw material is introduced into the reactor. The temperature is controlled at 150°C, the pressure is 0.5 Mpa, and the gas flow rate for introduction is 0.5 L / min. The hydrogen fluoride in the raw material reacts with germanium to be converted into germanium tetrafluoride.

[0039] Example 3

[0040] Step S1. Hydrogen (purity 99.99%) is introduced into the mixed filler of germanium oxide and activated carbon (mass ratio of germanium oxide to activated carbon is 1:5). The temperature is controlled at 100°C, the gas flow rate of hydrogen is controlled at 150 mL / min, and the purging time is 12 h.

[0041] Step S2. First, the reactor is purged with nitrogen (purity 99.99%), and then the reactor is vacuum-treated with a vacuum pump to a vacuum of -0.1 Mpa. The nitrogen flow rate is controlled at 150 mL / min, the reactor temperature is controlled at 100°C, and the nitrogen purging time is 24 h.

[0042] Step S3. The raw material germanium tetrafluoride (purity 99.99%) is introduced into the reactor. The temperature is controlled at 200°C, the pressure is 0.10 Mpa, the gas inlet flow rate is 1.5 L / min, and the hydrogen fluoride in the raw material reacts with germanium to be converted into germanium tetrafluoride.

[0043] Example 4

[0044] Step S1. Hydrogen (purity 99.99%) is introduced into the mixed filler of germanium oxide and activated carbon (mass ratio of germanium oxide to activated carbon is 1:3.5). The temperature is controlled at 120°C, the gas flow rate of hydrogen is controlled at 50 mL / min, and the purging time is 15 h.

[0045] Step S2. First, the reactor is purged with nitrogen (purity 99.99%), and then the reactor is vacuum-treated with a vacuum pump to a vacuum of -0.1 Mpa. The nitrogen flow rate is controlled at 50 mL / min, the reactor temperature is controlled at 130°C, and the nitrogen purging time is 20 h.

[0046] Step S3. The raw material germanium tetrafluoride (purity 99.99%) is introduced into the reactor. The temperature is controlled at 180°C, the pressure is 0.20 Mpa, the gas inlet flow rate is 1.2 L / min, and the hydrogen fluoride in the raw material reacts with germanium to be converted into germanium tetrafluoride.

[0047] Example 5

[0048] Step S1. Hydrogen (purity 99.99%) is introduced into the mixed filler of germanium oxide and activated carbon (mass ratio of germanium oxide to activated carbon is 1:4). The temperature is controlled at 120°C, the gas flow rate of hydrogen is controlled at 80 mL / min, and the purging time is 22 h.

[0049] Step S2. First, purge the reactor with nitrogen (the purity of nitrogen is 99.99%), and then vacuum-treat the reactor with a vacuum pump until the vacuum reaches -0.1 Mpa. Among them, control the flow rate of nitrogen to be 120 mL / min, control the temperature of the reactor to be 160 °C, and the purging time of nitrogen to be 18 h.

[0050] Step S3. Feed germanium tetrafluoride (purity 99.99%) into the reactor, control the temperature at 160 °C, the pressure at 0.30 Mpa, and the gas feed flow rate at 0.2 L / min. Hydrogen fluoride in the raw material reacts with germanium to be converted into germanium tetrafluoride.

[0051] Comparative Example 1

[0052] The difference between this comparative example and Example 1 is that in Step S3, the raw material germanium tetrafluoride has a purity of 98%.

[0053] Comparative Example 2

[0054] The difference between this comparative example and Example 1 is that in Step S2, there is no vacuum treatment.

[0055] Comparative Example 3

[0056] The difference between this comparative example and Example 1 is that in Step S2, there is no purging with nitrogen.

[0057] Comparative Example 4

[0058] The difference between this comparative example and Example 1 is that in Step S3, the gas feed flow rate of germanium tetrafluoride raw material is 5 L / min.

[0059] Comparative Example 5

[0060] The difference between this comparative example and Example 1 is that in Step S3, the temperature is controlled at 500 °C.

[0061] Performance Detection

[0062] Detect the content of hydrogen fluoride in germanium tetrafluoride after purification in Examples 1 - 5 and Comparative Examples 1 - 5. The results are shown in Table 1.

[0063] Table 1

[0064] Sample HF content before adsorption (ppm) HF content after adsorption (ppm) Example 1 50 8 Example 2 50 30 Example 3 50 25 Example 4 50 10 Example 5 50 28 Comparative Example 1 352 172 Comparative Example 2 50 35 Comparative Example 3 50 33 Comparative Example 4 50 42 Comparative Example 5 50 39

[0065] As can be seen from Examples 1 to 5, Comparative Examples 1 to 5 and Table 1, the method of the present application can further remove hydrogen fluoride in germanium tetrafluoride, and greatly improve the utilization rate of germanium tetrafluoride raw materials. It can be found from Comparative Example 1 that the method of the present application is more suitable for further purifying and removing hydrogen fluoride gas from germanium tetrafluoride with higher purity. In Comparative Examples 2 and 3, due to the lack of vacuum pumping or nitrogen purging in step S2, there may be more impurity gases in the subsequent packing, affecting the purification effect; in Comparative Examples 4 and 5, the reaction temperature or gas flow rate of germanium tetrafluoride was adjusted. It may be due to too high temperature or too large gas flow rate, resulting in incomplete reaction or formation of other substances, affecting the purification effect.

[0066] In summary, the method of the present application realizes the efficient removal of HF in germanium tetrafluoride, and at the same time has high purity, low cost and environmental friendliness, meeting the production requirements of semiconductor-grade GeF4.

[0067] The above are only the preferred embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application has been disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the equivalent embodiments by using the disclosed technical content without departing from the technical solution scope of the present application. However, any modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the technical solution content of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A method for reducing hydrogen fluoride in germanium tetrafluoride, characterized in that, It includes the following steps: Step S1. Purge the reactor filled with a mixed filler of germanium oxide and activated carbon with hydrogen. An oxidation-reduction reaction occurs between hydrogen and germanium oxide, and germanium oxide is reduced to metallic germanium to obtain a reduced mixed raw material. Step S2. First, purge the reduced mixed filler in the reactor with nitrogen, and then subject the reactor to a vacuum treatment. Step S3. Introduce a germanium tetrafluoride raw material containing hydrogen fluoride into the mixed filler in Step S2. The hydrogen fluoride in the germanium tetrafluoride raw material reacts with germanium to be converted into germanium tetrafluoride and collected.

2. The method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, In the mixed filler of germanium oxide and activated carbon in Step S1, the mass ratio of germanium oxide to activated carbon is 1:(3 - 5).

3. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, In Step S1, the temperature of the oxidation-reduction is 100°C - 200°C, the flow rate of hydrogen is 20 mL / min - 150 mL / min, and the purging time is 12 h - 24 h.

4. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, In Step S2, the flow rate of nitrogen is 20 mL / min - 150 mL / min, the purging time is 12 h - 24 h, and the temperature of the reactor is controlled at 100°C - 200°C.

5. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, In Step S2, the reactor is evacuated to a vacuum degree of -0.1 Mpa.

6. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, In Step S3, the purity of the raw material germanium tetrafluoride is 99.99%, and the introduced flow rate is 0.5 L / min - 1.5 L / min.

7. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, In Step S3, the reaction temperature is 150°C - 200°C, and the pressure is 0.10 Mpa - 0.5 Mpa.

8. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, The purity of hydrogen in Step S1 is ≥99.99%.

9. A method for reducing hydrogen fluoride in germanium tetrafluoride according to claim 1, characterized in that, The purity of nitrogen in Step S2 is ≥99.99%.