A synthesis device and preparation method of trimethylsilylamine

Abstract

The present invention relates to a synthesis device and preparation method for trisilylamine. The synthesis device comprises a reaction unit, a vacuum distillation unit, a filtration unit, a rectification unit, and a cleaning unit. The present invention improves the traditional synthesis route for preparing trisilylamine by reacting chlorosilane with ammonia. By adjusting and controlling the reaction conditions and the reaction apparatus, the stable synthesis of trisilylamine is promoted and the occurrence of side reactions is reduced. The synthesis device and preparation method provided by the present invention are safe, stable, and reliable, and have promising prospects for industrial application.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology and relates to a production device and method of a semiconductor silicon precursor, and in particular to a synthesis device and a preparation method of trisilylamine. Background Art

[0002] Trisilylamine (TSA), with the structural formula (SiH3)3N, is a volatile, colorless, pyrophoric, and readily hydrolyzable liquid. TSA is a key silicon precursor in semiconductor manufacturing, enabling film growth without direct plasma excitation. It provides silicon and nitrogen sources for semiconductor manufacturing and is widely used in high-aspect-ratio (HAR) silicon dielectric film structures.

[0003] The synthesis methods of trisilylamine mainly include: (1) the reaction of monohalosilane with ammonia to prepare TSA, which is divided into two types: liquid phase method and gas phase method, each with its own advantages and disadvantages; (2) the pyrolysis of perhydropolysilazane to prepare TSA; (3) the preparation of TSA by transamination. At present, the industrial process of preparing TSA mainly adopts the reaction of chlorosilane with ammonia:

[0004] 3SiH3Cl+4NH3→3NH4Cl+(SiH3)3N

[0005] This process route results in the main product being disilylamine (DSA) in the presence of excess ammonia, along with the formation of polysilazane and SiH4. There are two mechanisms for the decomposition of DSA:

[0006] x(SiH3)2NH→(SiH2NH) x +xSiH4

[0007] 3(SiH3)2NH→2(SiH3)3N+NH3

[0008] DSA, TSA and polysilazane are very unstable in the air and easily react violently with water to produce SiO2, H2 and NH3. Therefore, it is necessary to provide a synthesis device and preparation method for preparing (SiH3)3N with higher purity.

[0009] Burg and Kuljian et al. disclosed a method for preparing TSA with high yield in J.Am.Chem.Soc., 1950, 72, 3103. In this method, ammonia gas is slowly introduced into gaseous monochlorosilane from below, and the best yield of TSA is 80%. Wells and Schaeffer et al. disclosed a method for preparing TSA in batches by reacting chlorosilane gas with ammonia gas in J.Am.Chem.Soc., 1966, 88(1), 37-42. This method produces a large amount of ammonium chloride solid, which catalyzes the conversion of TSA into silane and other products. The intense heat release of chlorosilane and ammonia also exacerbates the degradation of TSA in the closed reactor, thereby reducing the yield of TSA to 77%.

[0010] To further increase the yield of TSA, it is necessary to reduce the proportion of DSA produced, which requires adding excess chlorosilane while minimizing the formation of polysilazane from TSA decomposition. However, chlorosilane is a very reactive gas, and adding excess chlorosilane increases the risk during the TSA synthesis process.

[0011] Further optimization of the process for preparing TSA by the reaction of monohalosilane with ammonia, controlling the reaction conditions that are favorable for the formation of TSA, and avoiding the following side reactions have become a hot topic of current research:

[0012] nNH3+3(SiH3)3N→3SiH4+(SiH3NSiH2)3+nNH3

[0013] (SiH3NSiH2)3+xNH3→ySiH4+zNH3+[polymeric materials]

[0014] The vapor phase process typically produces TSA with moderate to high yields and purity. However, when produced on an industrial scale, the process can produce a large amount of solid byproduct, NH4Cl, which accumulates on the internal surfaces of the equipment, clogging the reactor and the feed and discharge ports, affecting the normal production of TSA. Furthermore, the process also produces a large amount of DSA, which requires subsequent conversion to TSA. This conversion results in the contamination of the mixture with solid ammonium chloride, which requires additional separation steps. The separated ammonium chloride still contains some TSA / DSA, requiring special waste treatment processes.

[0015] The liquid-phase method uses low-temperature, pressurized conditions to disperse chlorosilanes and ammonia in an organic phase to react and produce TSA. The resulting ammonium chloride is dispersed in an organic solvent for easy removal, with virtually no downtime for the reactor, significantly reducing contamination of downstream purification equipment by ammonium chloride. However, the liquid-phase method cannot avoid the catalytic decomposition of TSA by ammonium chloride. Ammonium chloride also traps TSA, resulting in additional losses in TSA yield and requiring special post-reaction handling.

[0016] Therefore, there is currently no comprehensive TSA synthesis method, and actual production processes often require numerous separation steps, resulting in lower TSA yields. Therefore, there is a need to develop a synthesis apparatus and method for trisilylamine that produces stable yields, high purity, and safety. Summary of the Invention

[0017] The present invention aims to provide a synthesis device and preparation method of trisilylamine, which can achieve safe, stable and reliable production of trisilylamine, and the trisilylamine has high yield and purity and has industrial application value.

[0018] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0019] In a first aspect, the present invention provides a synthesis device for trisilylamine, the synthesis device comprising a reaction unit, a vacuum distillation unit, a filtration unit, a rectification unit, and a cleaning unit;

[0020] The reaction unit includes a reaction device, a solvent supply device, an ammonia feed pipeline and a chlorosilane feed pipeline; the reaction device is provided with a stirring device; the solvent supply device, the ammonia feed pipeline and the chlorosilane feed pipeline are independently connected to the reaction device; the ammonia feed pipeline is provided with a linkage valve; the linkage valve is interlocked with the stirring device;

[0021] The vacuum distillation unit includes a first condensing device, a second condensing device, a vacuum device, a cold trap, and a light phase storage tank; the first condensing device, the second condensing device, the cold trap, and the vacuum device are connected in sequence, and the feed port of the first condensing device is connected to the gas outlet of the reaction device; the condensate outlet of the second condensing device is connected to the light phase storage tank; the connecting pipeline between the cold trap and the light phase storage tank is connected to a balancing gas pipeline;

[0022] The filtration unit includes a first filtration system, a second filtration system, a product filtrate storage tank, and a solvent recovery storage tank; the first filtration system and the second filtration system each independently include at least two parallel filtration devices, and the inlet and outlet of the filtration device are respectively connected to the gas pipeline; the first filtration system is connected to the light phase storage tank and the product filtrate storage tank; the product filtrate storage tank is connected to the distillation unit; the second filtration system is connected to the reaction device and the solvent recovery storage tank;

[0023] The distillation unit comprises at least two distillation devices connected in series, and the bottom liquid outlet of the last distillation device is connected to the solvent recovery tank;

[0024] The cleaning unit includes a gas cleaning pipeline; the gas cleaning pipeline is connected to an ammonia feed pipeline and a chlorosilane feed pipeline respectively.

[0025] The linkage valve and stirring device described in the present invention are interlocked, meaning that the opening and closing of the linkage valve controls the intake of air into the ammonia feed line. When the stirring device is stopped, the linkage valve is closed; when the stirring device is running, the linkage valve is opened or closed based on the ammonia intake demand. By interlocking the linkage valve and stirring device, the present invention prevents the continued introduction of ammonia, which could cause a violent reaction between chlorosilane and locally high ammonia concentrations, and avoids the risk of accidents caused by untimely heat dissipation.

[0026] The reaction apparatus described herein is provided with a temperature control unit. The present invention does not impose any specific restrictions on the structure of the temperature control unit, as long as it can achieve temperature control of the reaction apparatus. Exemplarily, the temperature control unit includes, but is not limited to, a heat exchange coil and / or a heat exchange interlayer.

[0027] The first filtration system and the second filtration system provided by the present invention independently include at least two parallel filtration devices. The arrangement of the at least two parallel filtration devices can ensure the continuous operation of the filtration system and avoid the impact of the maintenance of any one of the filtration devices on the stable operation of the entire synthesis device.

[0028] The first filtering system includes at least two filtering devices connected in parallel, for example, 2, 3, 4, 5 or 6, but not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0029] The second filtering system includes at least two filtering devices connected in parallel, for example, 2, 3, 4, 5 or 6, but not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0030] The present invention avoids excessively low vacuum in the reaction device by arranging a cold trap and a balancing gas pipeline, thereby preventing the product from being sucked into the vacuum device and ensuring stable operation of the vacuum device.

[0031] The present invention is connected to the ammonia feed pipeline through a gas cleaning pipeline. When the ammonia feed pipeline is arranged at the end of the reaction device and ammonium chloride is attached or deposited, the ammonia gas can be turned off and then the ammonia feed pipeline can be flushed with protective gas to avoid the accumulation of ammonium chloride.

[0032] The gas used in the gas cleaning pipeline, the balance gas pipeline and the gas pipeline of the present invention independently include nitrogen and / or an inert gas, and the inert gas includes any one or a combination of at least two of helium, neon or argon. Typical but non-limiting combinations include a combination of helium and neon, a combination of neon and argon, a combination of helium and argon, or a combination of helium, neon and argon.

[0033] Illustratively, the solvent supply device described in the present invention is a conventional solvent supply device in the art, including but not limited to a solvent storage tank and a matching solvent delivery device. The present invention does not make any specific limitations here, as long as the supply of solvent in the reaction device can be achieved.

[0034] When the synthesis device provided by the present invention is used:

[0035] (a) first, using a cleaning unit to purge a synthesis device to ensure that the synthesis device is dry and clean; then, controlling the temperature of the reaction device to a process temperature, under stirring conditions of a stirring device, a solvent supply device provides a solvent to the reaction device, and a chlorosilane feed pipe is used to supply chlorosilane to the reaction device. After the chlorosilane feeding is completed, the cleaning unit purges the chlorosilane feed pipe;

[0036] (b) Under stirring conditions of the stirring device, ammonia is supplied to the reaction device at a uniform speed through the ammonia feed pipeline until the ammonia supply meets the process requirements. After the ammonia feeding is completed, the cleaning unit purges the ammonia feed pipeline; after the ammonia supply is completed, the stirring device continues to stir until the material in the reaction device is processed;

[0037] (c) The reaction apparatus is slowly depressurized, and then the pressure balance in the reaction apparatus is maintained using gas supplied by the vacuum apparatus and the cleaning apparatus. The NH3, DSA, TSA, a small amount of solvent, and entrained NH4Cl in the reaction apparatus are transferred out of the reaction apparatus by controlling the temperature of the reaction apparatus, the first condensing apparatus, and the second condensing apparatus; the NH3 is cooled by the first condensing apparatus and the second condensing apparatus and then collected by a cold trap; the DSA, TSA, a small amount of solvent, and entrained NH4Cl are passed through the first condensing apparatus and the second condensing apparatus and collected by a light phase storage tank;

[0038] (d) the product mixture collected in the light phase storage tank is filtered through a first filtration system to separate solid NH4Cl, and the remaining product filtrate enters a product filtrate storage tank; the product filtrate in the product filtrate storage tank is sequentially passed through a first rectification unit and a second rectification unit, and the parameters of the first rectification unit and the second rectification unit are adjusted so that the heavy components of the first rectification unit do not contain DSA; the heavy components of the first rectification unit are processed through the second rectification unit to obtain product TSA and a recovered solvent collected in a solvent recovery storage tank;

[0039] (e) The residual solvent in the reaction device contains ammonium chloride, which is filtered through a second filtering system to separate solid ammonium chloride, and the filtered solvent is recovered in a solvent recovery tank.

[0040] There is no particular order in which steps (d) and (e) are performed.

[0041] In order to ensure good dispersion of the by-product ammonium chloride, the stirring device continues stirring during the use of the synthesis device of the present invention; if the stirring device stops unexpectedly, the use of a linkage valve ensures that no ammonia gas enters the reaction device when the stirring is stopped.

[0042] Preferably, the end of the ammonia feed pipe in the present invention is arranged below the liquid level of the reaction device and does not affect stirring and dispersion.

[0043] Preferably, the material of the ammonia feed pipe of the present invention should not be easily attached by the by-product ammonium chloride salt and thus block the pipe, including but not limited to fluoroplastics.

[0044] Preferably, the first filter system includes a first filter device and a second filter device connected in parallel.

[0045] Preferably, the second filter system includes a third filter device and a fourth filter device connected in parallel.

[0046] Preferably, the distillation unit comprises a first distillation system and a second distillation system connected in series;

[0047] The first distillation system includes a first distillation device and a first product storage device connected to the light component discharge port of the first distillation device;

[0048] The second distillation system includes a second distillation device and a second product storage device connected to the light component discharge port of the second distillation device.

[0049] When the distillation unit described in the present invention is used, the conditions of the first distillation device are controlled so that the heavy components in the first distillation device do not contain DSA, and the light components mainly composed of DSA are collected in the first product storage device; the heavy components in the first distillation device are processed in the second distillation device, and the resulting light components are product TSA, which is collected in the second product storage device.

[0050] The first distillation device of the present invention includes but is not limited to a first distillation tower, and the first product storage device includes but is not limited to a first product storage tank; the second distillation device of the present invention includes but is not limited to a second distillation tower, and the second product storage device includes but is not limited to a second product storage tank.

[0051] Preferably, the connecting pipeline between the solvent supply device and the reaction device is also connected to a solvent recovery tank.

[0052] The invention realizes the recycling of the solvent in the solvent recovery tank by connecting the connecting pipeline between the solvent supply device and the reaction device with the solvent recovery tank.

[0053] Preferably, the linkage valve is a solenoid valve.

[0054] Preferably, the light phase storage tank is provided with a metering element.

[0055] The light phase storage tank provided with a metering device in the present invention refers to a level gauge, flow meter, or scale provided in the light phase storage tank. The metering device facilitates monitoring of the distillation output during vacuum distillation by the operator, thereby preventing the adverse effects of excessive solvent distillation on the dispersion and discharge of NH4Cl in the reaction unit.

[0056] In a second aspect, the present invention provides a method for preparing trisilylamine, which is carried out in the synthesis apparatus described in the first aspect and comprises the following steps:

[0057] (1) uniformly mixing the solvent and chlorosilane, and then introducing ammonia gas at a uniform rate; after the introduction of ammonia gas is completed, reacting until the chlorosilane is completely consumed to obtain a reaction solution;

[0058] (2) The reaction solution obtained in step (1) is distilled under reduced pressure, and NH3 is collected in a cold trap, and a distillate is obtained in a light phase storage tank;

[0059] (3) The distillate obtained in step (2) is filtered, subjected to a first distillation, and a second distillation in sequence to obtain the trimethylsilylamine.

[0060] The preparation method provided by the present invention is carried out in the synthesis apparatus described in the first aspect. Relying on the above-mentioned synthesis apparatus, by adjusting the preparation method of trisilylamine, an improvement is achieved in the traditional synthesis route for preparing TSA from chlorosilane and ammonia, avoiding and reducing the occurrence of side reactions, and capable of producing TSA safely, stably and reliably, with industrial application value.

[0061] Preferably, the temperature of the uniform mixing in step (1) is -50°C to 0°C, for example, -50°C, -40°C, -30°C, -20°C, -10°C or 0°C, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0062] Chlorosilane is a colorless gas with a pungent odor at room temperature and pressure. It has very active chemical properties and can undergo violent exothermic reactions with compounds containing active hydrogen, such as water, alcohol, phenol, ammonia, silanol, and organic acids. It may even burn or explode when exposed to open flames or high temperatures.

[0063] In the production process of trisilylamine, mass transfer and heat transfer are limited. Simple mixing, refrigeration and other methods are difficult to disperse the heat generated by the violent reaction in time. The reaction temperature is high, and under the conditions of ammonia or ammonium chloride, the side reaction of generating polysilazane is more likely to occur. When the temperature of the uniform mixing in step (1) is higher than 0°C, it is very easy to cause the reaction temperature to be too high, causing the proportion of polysilazane generated to increase. When the temperature of the uniform mixing is too low, the rate at which chlorosilane reacts with ammonia to generate TSA slows down, affecting the conversion efficiency of TSA; moreover, the lower mixing temperature also makes the selection of solvent more difficult, which is not conducive to the smooth progress of dispersion. Therefore, in order to safely and stably produce trisilylamine, the temperature of the uniform mixing in step (1) of the present invention is preferably -50°C to 0°C.

[0064] Preferably, the uniform mixing method in step (1) includes stirring, and the stirring speed is 50-300 r / min, for example, it can be 50 r / min, 100 r / min, 150 r / min, 200 r / min, 250 r / min or 300 r / min, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0065] Preferably, the mass ratio of the solvent to the chlorosilane in step (1) is (2-8):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0066] Preferably, the boiling point of the solvent in step (1) is above 100°C and the freezing point is below -25°C.

[0067] Preferably, the solvent in step (1) comprises any one of n-octane, n-nonane, n-decane, toluene, xylene or D series solvent oil, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of n-octane and n-nonane, a combination of n-nonane and toluene, a combination of toluene and xylene, a combination of xylene and D series solvent oil, a combination of n-octane, n-nonane and toluene, a combination of toluene, xylene and D series solvent oil, or a combination of n-octane, n-nonane, toluene, xylene or D series solvent oil, preferably n-nonane.

[0068] The solvent selected by the present invention does not evaporate excessive solvent when the product is completely evaporated by reduced pressure distillation, thereby avoiding affecting the dispersion of the by-product ammonium chloride due to the reduction of the solvent amount in the reaction device, and can also ensure the distillation efficiency. Among them, the boiling point of n-octane is 125°C and the freezing point is -57°C; the boiling point of n-decane is 174°C and the freezing point is -30°C; the boiling point of toluene is 110.6°C and the freezing point is -94.9°C; the boiling range of xylene is 135-145°C, the freezing point of o-xylene is -25.2°C, the freezing point of m-xylene is -48°C, and the freezing point of p-xylene is 12-13°C; taking D40 as an example, its boiling range is 150-210°C and the freezing point is -40°C.

[0069] The boiling point of n-nonane is 151°C and the freezing point is -53°C. It does not solidify or clump during the uniform mixing process in step (1), and can stabilize the dispersion reaction. Furthermore, the vapor pressure of n-nonane at 0°C is 0.1 kPa. When the product is completely evaporated by vacuum distillation, the amount of solvent evaporated is reduced. During the second distillation, the boiling point and vapor pressure of n-nonane and TSA differ significantly, which can also ensure distillation efficiency. Therefore, the solvent of the present invention is preferably n-nonane.

[0070] Preferably, the mass ratio of ammonia to chlorosilane in step (1) is (0.35-0.4):1, for example, it can be 0.35:1, 0.36:1, 0.37:1, 0.38:1, 0.39:1 or 0.4:1, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0071] Preferably, the time for introducing ammonia gas in step (1) is 3-12 hours, for example, 3 hours, 5 hours, 6 hours, 8 hours, 10 hours or 12 hours, but is not limited to the listed values, and other values not listed within the numerical range are also applicable. When the time for introducing ammonia gas is less than 3 hours, the reaction between chlorosilane and ammonia in the system is too rapid, the heat generated by the reaction is not conducive to timely dispersion, the system temperature is likely to rise, and the generated TSA is easily destroyed, resulting in the production of more polysilazane; when the time for introducing ammonia gas exceeds 12 hours, the production efficiency of TSA is affected.

[0072] Preferably, the process of introducing ammonia gas in step (1) is accompanied by stirring, and the stirring speed is 50-300 r / min, for example, it can be 50 r / min, 100 r / min, 150 r / min, 200 r / min, 250 r / min or 300 r / min, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0073] Preferably, the reaction process in step (1) is accompanied by stirring, and the stirring speed is 50-300 r / min, for example, it can be 50 r / min, 100 r / min, 150 r / min, 200 r / min, 250 r / min or 300 r / min, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0074] Preferably, the absolute pressure of the reaction in step (1) is 1-6 bar, for example, 1 bar, 2 bar, 3 bar, 4 bar, 5 bar or 6 bar, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0075] The absolute pressure of the reaction described herein refers to the pressure within the reaction apparatus during the reaction. Due to the consumption of ammonia, the absolute pressure of the reaction fluctuates. Therefore, the absolute pressure of the reaction described herein is the equilibrium pressure during the reaction. When the introduction of ammonia fails to maintain the absolute pressure of the reaction, nitrogen and / or an inert gas is introduced to compensate.

[0076] The temperature of uniformly introducing ammonia gas in step (1) of the present invention and the temperature during the reaction are both the same as the temperature of uniform mixing. The preparation method provided by the present invention avoids the step of recovering the hazardous raw material chlorosilane by controlling the reaction conditions, and also avoids the problem of ammonium salt precipitation caused by the reaction of excess chlorosilane with residual DSA; moreover, the reaction process is carried out under conditions of -50°C to 0°C, avoiding the danger caused by the inability to dissipate heat in time during the reaction and also reducing the formation of polysilazane.

[0077] Preferably, the absolute pressure of the reduced pressure distillation in step (2) is 0.2-0.8 bar, for example, it can be 0.2 bar, 0.3 bar, 0.4 bar, 0.5 bar, 0.6 bar, 0.7 bar or 0.8 bar, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0078] Preferably, the temperature of the reduced pressure distillation in step (2) is -30°C to 20°C, for example, -30°C, -20°C, -10°C, 0°C, 10°C or 20°C, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0079] The temperature of the reduced pressure distillation in the present invention is the temperature of the reaction device; as a preferred technical solution, in order to control the amount of solvent evaporated, the temperatures of the first condensing device and the second condensing device are independently -20°C to 0°C, for example, -20°C, -15°C, -10°C, -5°C or 0°C, but are not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0080] The endpoint of the reduced pressure distillation in step (2) of the present invention is to completely distill out DSA and TSA.

[0081] During the vacuum distillation of the present invention, it is necessary to evaporate excess ammonia before DSA and TSA evaporate the system (DSA boiling point 36°C, TSA boiling point 52°C), so the vacuum distillation needs to start at a lower temperature; the ammonia evaporation process is an endothermic process, and the temperature in the reaction device will further decrease during the ammonia evaporation process. Therefore, if the temperature of the vacuum distillation is lower than -30°C, as the vacuum distillation proceeds, the temperature of the system will gradually decrease to below the liquefaction point of ammonia (-33.5°C), affecting the further evaporation of ammonia; when the temperature is lower than the freezing point of the solvent, it will cause the system to become viscous and even the solvent to agglomerate, affecting the distillation of the product; and when the temperature of the vacuum distillation exceeds 20°C, ammonia and the by-product ammonium chloride will accelerate the decomposition of TSA and increase the formation of polysilazane. Therefore, it is necessary to control the temperature of the vacuum distillation to be between -30°C and 20°C.

[0082] The present invention controls the conditions of the reduced pressure distillation, which not only can realize the reduced pressure distillation of the product, but also can distill out excess ammonia, thereby reducing the damage to the product TSA caused during the purification process.

[0083] Preferably, the filtration in step (3) is boosted filtration, and the gas pressure of the boosted filtration is 1-5 bar.

[0084] The saturated vapor pressure of the products DSA and TSA produced by the preparation method of the present invention is relatively high, and ammonium chloride also has a trapping effect on TSA and DSA. Conventional reduced-pressure filtration or normal-pressure filtration cannot fully utilize DSA and TSA. However, pressurized filtration can also shorten the filtration time and avoid the risk of catalytic decomposition of the product.

[0085] The first distillation of the present invention is carried out in a first distillation device, and the first distillation is used to prevent DSA from being contained in the heavy components of the first distillation device. The second distillation of the present invention is carried out in a second distillation device, and the second distillation is used to obtain the product TSA at the top of the second distillation device.

[0086] Preferably, in step (3), the bottom temperature of the first distillation is 90-100°C, and the top temperature is 45-50°C.

[0087] The bottom temperature of the first distillation in the present invention is 90-100°C, for example, 90°C, 92°C, 95°C, 96°C, 98°C or 100°C, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0088] The tower top temperature of the first distillation of the present invention is 45-50°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0089] The present invention does not impose any specific limitation on the reflux ratio of the first distillation, as long as the heavy components of the first distillation unit do not contain DSA and the bottom temperature and top temperature of the first distillation meet the requirements.

[0090] Preferably, the bottom temperature of the second distillation in step (3) is 110-120°C, and the top temperature is 55-60°C.

[0091] The bottom temperature of the second distillation tower of the present invention is 110-120°C, for example, it can be 110°C, 112°C, 115°C, 116°C, 118°C or 120°C, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0092] The tower top temperature of the second distillation of the present invention is 55-60°C, for example, it can be 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0093] The present invention does not impose a specific limit on the reflux ratio of the second distillation, as long as the second distillation can produce the TSA product. Exemplarily, the reflux ratio of the second distillation is 8-12, for example, 8, 9, 10, 11, or 12, but is not limited to the listed values, and other values within the numerical range not listed are also applicable.

[0094] Compared with the prior art, the present invention has the following beneficial effects:

[0095] (1) The trisilylamine synthesis device provided by the present invention can timely purify the produced TSA, thereby preventing the damage of impurities such as ammonia and ammonium chloride to TSA, thereby increasing the safety of the TSA production process;

[0096] (2) The preparation method provided by the present invention is carried out in a specific synthesis device. Relying on the specific synthesis device, by adjusting the preparation method of trisilylamine, the traditional synthesis route of TSA prepared by chlorosilane and ammonia is improved, the occurrence of side reactions is avoided and reduced, and TSA can be produced safely, stably and reliably, which has industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 This is a schematic diagram of the synthesis apparatus for trisilylamine provided in Example 1.

[0098] Among them: 11, reaction device; 12, solvent supply device; 21, first condensing device; 22, second condensing device; 23, cold trap; 24, vacuum device; 25, light phase storage tank; 31, first filtering device; 32, second filtering device; 33, product filtrate storage tank; 34, third filtering device; 35, fourth filtering device; 36, solvent recovery storage tank; 41, first distillation device; 42, first product storage device; 43, second distillation device; 44, second product storage device. DETAILED DESCRIPTION

[0099] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are only provided to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0100] Example 1

[0101] This embodiment provides a Figure 1 The synthesis device of trisilylamine shown includes a reaction unit, a vacuum distillation unit, a filtration unit, a rectification unit and a cleaning unit;

[0102] The reaction unit includes a reaction device 11, a solvent supply device 12, an ammonia feed pipeline, and a chlorosilane feed pipeline; the reaction device 11 is provided with a stirring device; the solvent supply device 12, the ammonia feed pipeline, and the chlorosilane feed pipeline are independently connected to the reaction device 11; the ammonia feed pipeline is provided with a linkage valve; the linkage valve is interlocked with the stirring device; the linkage valve is a solenoid valve; the end of the ammonia feed pipeline is arranged below the liquid level of the reaction device 11 and does not affect stirring and dispersion; the material of the ammonia feed pipeline is fluoroplastic;

[0103] The vacuum distillation unit includes a first condensing device 21, a second condensing device 22, a vacuum device 24, a cold trap 23 and a light phase storage tank 25; the first condensing device 21, the second condensing device 22, the cold trap 23 and the vacuum device 24 are connected in sequence, and the feed port of the first condensing device 21 is connected to the gas outlet of the reaction device 11; the condensate outlet of the second condensing device 22 is connected to the light phase storage tank 25; the connecting pipeline between the cold trap 23 and the vacuum device 24 is connected to a balancing gas pipeline; the light phase storage tank 25 is provided with a liquid level gauge;

[0104] The filtration unit includes a first filtration system, a second filtration system, a product filtrate storage tank 33, and a solvent recovery storage tank 36; the first filtration system includes a first filtration device 31 and a second filtration device 32 connected in parallel, and the second filtration system includes a third filtration device 34 and a fourth filtration device 35 connected in parallel. The inlets and outlets of the first filtration device 31, the second filtration device 32, the third filtration device 34, and the fourth filtration device 35 are respectively connected to the gas pipeline; the first filtration system is connected to the light phase storage tank 25 and the product filtrate storage tank 33; the product filtrate storage tank 33 is connected to the distillation unit; the second filtration system is connected to the reaction device 11 and the solvent recovery storage tank 36;

[0105] The distillation unit includes a first distillation system and a second distillation system connected in series; the first distillation system includes a first distillation device 41 and a first product storage device 42 connected to the light component discharge port of the first distillation device 41; the second distillation system includes a second distillation device 43 and a second product storage device 44 connected to the light component discharge port of the second distillation device 43; the bottom liquid outlet of the second distillation device 43 is connected to the solvent recovery storage tank 36; the first distillation device 41 is a first distillation tower, the second distillation device 43 is a second distillation tower, and the bottom of the first distillation tower is connected to the feed port of the second distillation tower;

[0106] The connection pipeline between the solvent supply device 12 and the reaction device 11 is connected to the solvent recovery tank 36 .

[0107] The cleaning unit includes a gas cleaning pipeline; the gas cleaning pipeline is connected to an ammonia feed pipeline and a chlorosilane feed pipeline respectively.

[0108] The gas used in the gas cleaning pipeline, the balancing gas pipeline and the gas pipeline described in this embodiment is nitrogen gas respectively and independently.

[0109] When the synthesis device provided in this embodiment is used:

[0110] (a) First, a cleaning unit is used to purge the synthesis device to ensure that the synthesis device is dry and clean; then, the temperature of the reaction device 11 is controlled to the process temperature, and under the stirring condition of the stirring device, the solvent supply device 12 provides a solvent to the reaction device 11, and chlorosilane is provided to the reaction device 11 through a chlorosilane feed pipe. After the chlorosilane feeding is completed, the cleaning unit purges the chlorosilane feed pipe;

[0111] (b) Under stirring conditions of the stirring device, ammonia is supplied to the reaction device 11 at a uniform rate through the ammonia feed pipe until the ammonia supply meets the process requirements. After the ammonia feeding is completed, the cleaning unit purges the ammonia feed pipe; after the ammonia supply is completed, the stirring device continues stirring until the material in the reaction device 11 is processed;

[0112] (c) The pressure of the reaction device 11 is slowly released, and then the pressure balance in the reaction device 11 is maintained by using the gas supplied by the vacuum device 24 and the cleaning device. The NH3, DSA, TSA, a small amount of solvent, and entrained NH4Cl in the reaction device 11 are transferred out of the reaction device 11 by controlling the temperature of the reaction device 11, the first condensing device 21, and the second condensing device 22; the NH3 is cooled by the first condensing device 21 and the second condensing device 22 and then collected by the cold trap 23; the DSA, TSA, a small amount of solvent, and entrained NH4Cl are passed through the first condensing device 21 and the second condensing device 22 and collected by the light phase storage tank 25;

[0113] (d) The product mixture collected in the light phase storage tank 25 is filtered through the first filtration system to separate solid NH4Cl, and the remaining product filtrate enters the product filtrate storage tank 33; the product filtrate in the product filtrate storage tank 33 is sequentially passed through the first distillation unit 41 and the second distillation unit 43, and the parameters of the first distillation unit 41 and the second distillation unit 43 are adjusted so that the heavy component of the first distillation unit 41 does not contain DSA; the heavy component of the first distillation unit 41 is processed through the second distillation unit 43 to obtain product TSA and recovered solvent recovered in the solvent recovery storage tank 36;

[0114] (e) The residual solvent in the reaction device 11 contains ammonium chloride, which is filtered by the second filtering system to separate solid ammonium chloride. The filtered solvent is recovered in the solvent recovery tank 36.

[0115] There is no particular order in which steps (d) and (e) are performed.

[0116] In order to ensure good dispersion of the by-product ammonium chloride, the stirring device continues stirring during the use of the synthesis device of the present invention; if the stirring device stops unexpectedly, the use of a linkage valve ensures that no ammonia gas enters the reaction device when the stirring is stopped.

[0117] Application Example 1

[0118] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1, the method comprising the following steps:

[0119] (1) n-nonane and chlorosilane are uniformly mixed in a reaction device, and then ammonia is introduced at a uniform rate; after the introduction of ammonia is completed, the reaction is carried out until the chlorosilane is completely consumed to obtain a reaction liquid; the mass ratio of n-nonane to chlorosilane is 4:1; the mass ratio of ammonia to chlorosilane is 0.36:1, and the introduction time of ammonia is 7 hours; the absolute pressure of the reaction is 3 bar; during step (1), the temperature in the reaction device is maintained at -30°C;

[0120] (2) The reaction liquid obtained in step (1) is distilled under reduced pressure, and NH3 is collected in a cold trap, and distillate is obtained in a light phase storage tank; the absolute pressure of the reduced pressure distillation is 0.4 bar, and the temperature of the reaction device is adjusted within the range of -30°C to 20°C, and NH3, DSA and TSA, a small amount of n-nonane and trace amounts of NH4Cl entrained in the reaction device are sequentially introduced; during the reduced pressure distillation, the temperatures of the first condenser and the second condenser are independently set to -10°C;

[0121] (3) The distillate obtained in step (2) is filtered, subjected to a first distillation, and then to a second distillation to obtain the trimethylsilylamine; the first distillation has a bottom temperature of 100°C, a top temperature of 50°C, a reflux ratio of 21, and a plate number of 60; the second distillation has a bottom temperature of 120°C, a top temperature of 60°C, a reflux ratio of 12, and a plate number of 60;

[0122] In order to disperse the by-product ammonium chloride well, during the process of the method, the stirring device continuously stirs at a stirring speed of 200 r / min.

[0123] Application Example 2

[0124] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1, the method comprising the following steps:

[0125] (1) uniformly mixing n-nonane and chlorosilane, and then uniformly introducing ammonia; after the introduction of ammonia, reacting until the chlorosilane is completely consumed to obtain a reaction solution; the mass ratio of n-nonane to chlorosilane is 8:1; the mass ratio of ammonia to chlorosilane is 0.4:1, and the introduction time of ammonia is 3 hours; the absolute pressure of the reaction is 1 bar; during the process of step (1), the temperature in the reaction device is maintained at -30°C;

[0126] (2) The reaction liquid obtained in step (1) is distilled under reduced pressure, and NH3 is collected in a cold trap, and distillate is obtained in a light phase storage tank; the absolute pressure of the reduced pressure distillation is 0.8 bar, and the temperature of the reaction device is adjusted within the range of -30°C to 20°C, and NH3, DSA and TSA, a small amount of n-nonane and trace amounts of NH4Cl entrained in the reaction device are sequentially introduced; during the reduced pressure distillation, the temperatures of the first condenser and the second condenser are independently set to 0°C;

[0127] (3) The distillate obtained in step (2) is filtered, subjected to a first distillation, and then to a second distillation to obtain the trimethylsilylamine; the bottom temperature of the first distillation is 95°C, the top temperature is 48°C, the reflux ratio is 20, and the number of plates is 60; the bottom temperature of the second distillation is 115°C, the top temperature is 58°C, the reflux ratio is 10, and the number of plates is 60;

[0128] In order to disperse the by-product ammonium chloride well, during the process of the method, the stirring device continuously stirs at a stirring speed of 50 r / min.

[0129] Application Example 3

[0130] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1, the method comprising the following steps:

[0131] (1) uniformly mixing n-nonane and chlorosilane, and then uniformly introducing ammonia; after the introduction of ammonia, reacting until the chlorosilane is completely consumed to obtain a reaction solution; the mass ratio of n-nonane to chlorosilane is 2:1; the mass ratio of ammonia to chlorosilane is 0.35:1, and the introduction time of ammonia is 3 hours; the absolute pressure of the reaction is 1 bar; during the process of step (1), the temperature in the reaction device is maintained at -30°C;

[0132] (2) The reaction liquid obtained in step (1) is distilled under reduced pressure, and NH3 is collected in a cold trap, and a distillate is obtained in a light phase storage tank; the absolute pressure of the reduced pressure distillation is 0.2 bar, and the temperature of the reaction device is adjusted within the range of -30°C to 20°C, and NH3, DSA and TSA, a small amount of n-nonane and a trace amount of NH4Cl entrained in the reaction device are sequentially introduced; during the reduced pressure distillation, the temperature of the first condensing device and the second condensing device are independently set to -20°C;

[0133] (3) The distillate obtained in step (2) is filtered, subjected to a first distillation, and then to a second distillation to obtain the trimethylsilylamine; the bottom temperature of the first distillation is 90°C, the top temperature is 45°C, the reflux ratio is 18, and the number of plates is 60; the bottom temperature of the second distillation is 110°C, the top temperature is 55°C, the reflux ratio is 8, and the number of plates is 60;

[0134] In order to disperse the by-product ammonium chloride well, during the process of the method, the stirring device continuously stirs at a stirring speed of 300 r / min.

[0135] Application Example 4

[0136] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the temperature in the reaction device is maintained at -50°C during step (1), the rest is the same as in Application Example 1.

[0137] Application Example 5

[0138] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the temperature in the reaction device is maintained at -40°C during step (1), the rest is the same as in Application Example 1.

[0139] Application Example 6

[0140] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the temperature in the reaction device is maintained at -20°C during step (1), the rest is the same as in Application Example 1.

[0141] Application Example 7

[0142] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the temperature in the reaction device is maintained at -10°C during step (1), the rest is the same as in Application Example 1.

[0143] Application Example 8

[0144] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the temperature in the reaction device is maintained at -0°C during step (1), the rest is the same as in Application Example 1.

[0145] Application Example 9

[0146] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the temperature in the reaction device is maintained at -60°C during step (1), the rest is the same as in Application Example 1.

[0147] In this application example, since the temperature in the reaction apparatus was too low, the solvent agglomerates and trisilylamine cannot be synthesized.

[0148] Application Example 10

[0149] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the initial temperature in the reaction device during step (1) is 10°C, the rest is the same as in Application Example 1.

[0150] Application Example 11

[0151] This application example provides a method for preparing trimethylsilylamine using the synthesis device provided in Example 1. Except that the mass of n-nonane in step (1) is replaced by n-octane, the rest is the same as that in Application Example 1.

[0152] Application Example 12

[0153] This application example provides a method for preparing trimethylsilylamine using the synthesis device provided in Example 1. Except that the mass of n-nonane in step (1) is replaced by toluene, the rest is the same as that in Application Example 1.

[0154] Application Example 13

[0155] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the mass of n-nonane in step (1) is replaced by a combination of toluene and n-nonane in a mass ratio of 1:1, the rest is the same as in Application Example 1.

[0156] Application Example 14

[0157] This application example provides a method for preparing trisilylamine using the synthesis device provided in Example 1. Except that the mass of n-nonane in step (1) is replaced by xylene, the rest is the same as that in Application Example 1.

[0158] The time taken to synthesize and purify trisilylamine using the method provided in Example 1-14 was recorded, the yield was calculated, and the purity of the resulting trisilylamine was determined. Yield = (mass of trisilylamine / theoretical mass of trisilylamine based on chlorosilane) × 100%. Purity was analyzed by gas chromatography, and the results are shown in Table 1.

[0159] Table 1

[0160]

[0161]

[0162] In summary, the synthesis device of trisilylamine provided by the present invention can timely purify the output TSA, avoid the damage of impurities such as ammonia and ammonium chloride to TSA, and increase the safety of the TSA production process; the preparation method provided by the present invention is carried out in a specific synthesis device. Relying on the specific synthesis device, by adjusting the preparation method of trisilylamine, an improvement is achieved in the traditional synthesis route of preparing TSA from chlorosilane and ammonia, avoiding and reducing the occurrence of side reactions, and can produce TSA safely, stably and reliably, and has industrial application value.

[0163] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A synthesis device for trisilylamine, characterized in that, The synthesis device includes a reaction unit, a vacuum distillation unit, a filtration unit, a rectification unit and a cleaning unit; The reaction unit includes a reaction device, a solvent supply device, an ammonia feed pipeline and a chlorosilane feed pipeline; the reaction device is provided with a stirring device; the solvent supply device, the ammonia feed pipeline and the chlorosilane feed pipeline are independently connected to the reaction device; the ammonia feed pipeline is provided with a linkage valve; the linkage valve is interlocked with the stirring device; The vacuum distillation unit includes a first condensing device, a second condensing device, a vacuum device, a cold trap, and a light phase storage tank; the first condensing device, the second condensing device, the cold trap, and the vacuum device are connected in sequence, and the feed port of the first condensing device is connected to the gas outlet of the reaction device; the condensate outlet of the second condensing device is connected to the light phase storage tank; the connecting pipeline between the cold trap and the light phase storage tank is connected to a balancing gas pipeline; The filtration unit includes a first filtration system, a second filtration system, a product filtrate storage tank, and a solvent recovery storage tank; the first filtration system and the second filtration system each independently include at least two parallel filtration devices, and the inlet and outlet of the filtration device are respectively connected to the gas pipeline; the first filtration system is connected to the light phase storage tank and the product filtrate storage tank; the product filtrate storage tank is connected to the distillation unit; the second filtration system is connected to the reaction device and the solvent recovery storage tank; The connecting pipeline between the solvent supply device and the reaction device is also connected to the solvent recovery tank; The distillation unit includes a first distillation system and a second distillation system connected in series; the first distillation system includes a first distillation device and a first product storage device connected to the light component discharge port of the first distillation device; the second distillation system includes a second distillation device and a second product storage device connected to the light component discharge port of the second distillation device; the bottom liquid outlet of the second distillation device is connected to the solvent recovery tank; The cleaning unit includes a gas cleaning pipeline; the gas cleaning pipeline is connected to an ammonia feed pipeline and a chlorosilane feed pipeline respectively.

2. The synthesis device according to claim 1, characterized in that The first filter system includes a first filter device and a second filter device connected in parallel.

3. The synthesis device according to claim 1, characterized in that The second filter system includes a third filter device and a fourth filter device connected in parallel.

4. The synthesis device according to claim 1, characterized in that The linkage valve is a solenoid valve.

5. The synthesis device according to claim 1, characterized in that The light phase storage tank is provided with a metering member.

6. A method for preparing trisilylamine, characterized in that: The preparation method is carried out in the synthesis device according to any one of claims 1 to 5, comprising the following steps: (1) uniformly mixing the solvent and chlorosilane, and then introducing ammonia gas at a uniform rate; after the introduction of ammonia gas is completed, reacting until the chlorosilane is completely consumed to obtain a reaction solution; (2) The reaction solution obtained in step (1) is distilled under reduced pressure, and NH3 is collected in a cold trap, and a distillate is obtained in a light phase storage tank; (3) The distillate obtained in step (2) is filtered, subjected to a first distillation, and a second distillation in sequence to obtain the trimethylsilylamine.

7. The preparation method according to claim 6, characterized in that The temperature of the uniform mixing in step (1) is -50°C to 0°C.

8. The preparation method according to claim 6, characterized in that The uniform mixing method in step (1) includes stirring, and the stirring speed is 50-300r / min.

9. The preparation method according to claim 6, characterized in that The mass ratio of the solvent to chlorosilane in step (1) is (2-8):

1.

10. The preparation method according to claim 6, characterized in that The boiling point of the solvent in step (1) is above 100° C. and the freezing point is below -25° C.

11. The preparation method according to claim 6, characterized in that The solvent in step (1) includes any one of n-octane, n-nonane, n-decane, toluene, xylene or D series solvent oil, or a combination of at least two thereof.

12. The preparation method according to claim 6, characterized in that The mass ratio of ammonia to chlorosilane in step (1) is (0.35-0.4):

1.

13. The preparation method according to claim 6, characterized in that The time for introducing ammonia in step (1) is 3-12 hours.

14. The preparation method according to claim 6, characterized in that The process of introducing ammonia in step (1) is accompanied by stirring, and the stirring speed is 50-300r / min.

15. The preparation method according to claim 6, characterized in that The reaction process in step (1) is accompanied by stirring, and the stirring speed is 50-300r / min.

16. The preparation method according to claim 6, characterized in that The absolute pressure of the reaction in step (1) is 1-6 bar.

17. The preparation method according to claim 6, characterized in that The absolute pressure of the reduced pressure distillation in step (2) is 0.2-0.8 bar.

18. The preparation method according to claim 6, characterized in that: The temperature of the reduced pressure distillation in step (2) is -30°C to 20°C.

19. The preparation method according to claim 6, characterized in that The filtration in step (3) is pressurized filtration, and the gas pressure of the pressurized filtration is 1-5 bar.

20. The preparation method according to claim 6, characterized in that In step (3), the bottom temperature of the first distillation is 90-100°C, and the top temperature is 45-50°C.

21. The preparation method according to claim 6, characterized in that In step (3), the bottom temperature of the second distillation is 110-120°C, and the top temperature is 55-60°C.

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