Preparation method of electronic-grade bis (diethylamino) silane

Abstract

The invention discloses a preparation method of electronic-grade bis (diethylamino) silane, which comprises the following steps: S1: under the protection of inert atmosphere, adding diethylamine and a hydrocarbon solvent into a reactor, then adding an organic lithium compound into the system, controlling the temperature at-20 DEG C to 0 DEG C, and reacting for several hours to obtain lithium diethylamino; s2, adding dichlorosilane into the system, controlling the temperature at-25 DEG C to-15 DEG C, reacting for several hours, and filtering and distilling after the reaction is finished to obtain bis (diethylamino) silane; purifying the bis (diethylamino) silane obtained in the step S2; the purification process is additionally adopted on the basis of the original processing technology, so that the purity of the product is greatly improved; the method only needs a single hydrocarbon solvent, and the raw materials are conventional commercially available products, so that the synthesis cost and the reaction toxicity are reduced, and the method has better operability and is suitable for industrial application; the method is high in yield and easy for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of material preparation, and in particular to a method for preparing electronic-grade bis(diethylamino)silane. Background Art

[0002] The continuous development of the semiconductor manufacturing industry has made it necessary to find high-K and metal gate material precursors suitable for ALD and CVD. For the 32nm technology node, issues such as material volatility, transport mode and purity have become crucial; with the substantial increase in information storage and acquisition, the demand for higher K value materials has also continued to increase; choosing the right high-K material can meet production requirements such as dielectric constant, thermodynamic stability, gate electrode compatibility and interface layer stability, which is a hot topic in the current ALD research field.

[0003] Bis(diethylamino)silane is unstable at high temperatures and is extremely prone to spontaneous combustion when exposed to air. It reacts violently with water and burns and explodes. The product should be placed in a sealed stainless steel container and operated in an inert gas to avoid contact with water and air. Protective measures (protective gloves, protective glasses, protective masks) should be taken when humans operate cylinders.

[0004] Bis(diethylamino)silane is a solid-liquid mixed precursor that can be used with other co-reactants to deposit oxide, nitride, sulfide and other thin films. It is used in optical coatings, power devices, storage devices, etc. It is a key raw material for growing hafnium nitride or hafnium oxide by chemical vapor deposition (CVD) or atomic layer deposition processes.

[0005] Based on the above situation, our company has developed and proposed a method for preparing bis(diethylamino)silane to achieve the preparation of bis(diethylamino)silane products with a purity of 99.99%. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing electronic grade bis(diethylamino)silane, so as to realize the production and preparation of high-purity bis(diethylamino)silane products and fill the gap in the current technology.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A method for preparing electronic grade bis(diethylamino)silane comprises the following steps:

[0009] S1: under the protection of an inert atmosphere, diethylamine and a hydrocarbon solvent are added to a reactor, and then an organic lithium compound is added to the system, the temperature is controlled at -20°C to 0°C, and diethylamide lithium is obtained after reacting for several hours;

[0010] S2: adding dichlorosilane to the system, controlling the temperature at -25°C to -15°C, reacting for several hours, filtering and distilling after the reaction to obtain bis(diethylamino)silane;

[0011] S3: subjecting the obtained bis(diethylamino)silane to a reflux reaction for 3 to 9 hours; after cooling, removing the byproduct lithium chloride through a solid-liquid separator to obtain a first solution;

[0012] S4: transferring the obtained first solution to a distiller, first reducing the pressure to 10-50 mm Hg to evaporate the alkane solvent; and then reducing the pressure to 1-5 mm Hg to evaporate the product bis(diethylamino)silane;

[0013] S5: The distilled product bis(diethylamino)silane is subjected to adsorption and filtration to obtain electronic grade bis(diethylamino)silane.

[0014] In a preferred embodiment, the hydrocarbon solvent is a normal alkane having 4 to 8 carbon atoms.

[0015] In a preferred embodiment, the hydrocarbon solvent is n-hexane.

[0016] In a preferred embodiment, the organic lithium compound is a normal chain hydrocarbon lithium having 4 to 6 carbon atoms.

[0017] In a preferred embodiment, the normal chain alkyl lithium is n-butyl lithium.

[0018] In a preferred embodiment, in step S1, the temperature is -15°C and the reaction time is 10 hours; in step S2, the temperature is -20°C and the reaction time is 10 hours.

[0019] In a preferred embodiment, in step S3, the reflux reaction time is 4 hours.

[0020] In a preferred solution, in step S4, the pressure is first reduced to 30 mm Hg, and then reduced to 3 mm Hg.

[0021] In a preferred embodiment, the molar ratio of diethylamine to the organic lithium compound during the reaction is 1-1.2:1, the molar ratio of the organic lithium compound to dichlorosilane is 4:1-1.2, and the inert atmosphere is a nitrogen atmosphere.

[0022] In a preferred embodiment, the molar ratio of the diethylamine to the organic lithium compound is 1.1:1, and the molar ratio of the organic lithium compound to dichlorosilane is 4:1.1.

[0023] Due to the application of the above technical solution, the beneficial effects of the present application compared with the prior art are:

[0024] The present application provides a method for preparing electronic-grade bis(diethylamino)silane, which additionally adopts a purification process on the original processing technology, firstly performs a reflux reaction, then performs multiple vacuum distillations, and finally performs adsorption and filtration, thereby greatly improving the purity of the product, so that the purity and particle size of the product both better meet the product requirements of the electronics industry; moreover, the method of the present invention only requires a single hydrocarbon solvent, and its raw materials are all conventional commercially available products, which reduces the synthesis cost and the toxicity of the reaction, has better operability, and is suitable for industrial application; the yield of the present invention is high, and it is easy to scale up production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The present invention is a schematic flow diagram of a method for preparing electronic grade bis(diethylamino)silane;

[0027] Figure 2 It is a comparative schematic diagram of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0031] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0032] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] See also Figure 1 The present application provides a method for preparing electronic grade bis(diethylamino)silane, comprising the following steps:

[0035] S1: under the protection of an inert atmosphere, diethylamine and a hydrocarbon solvent are added to a reactor, and then an organic lithium compound is added to the system, and the temperature is controlled at -20°C to 0°C. After reacting for several hours, diethylamide lithium is obtained; wherein the hydrocarbon solvent is a normal alkane with 4 to 8 carbon atoms, such as n-hexane; and the organic lithium compound is a normal chain hydrocarbon lithium with 4 to 6 carbon atoms, such as n-butyl lithium;

[0036] S2: adding dichlorosilane to the system, controlling the temperature at -25°C to -15°C, reacting for several hours, filtering and distilling after the reaction to obtain bis(diethylamino)silane;

[0037] S3: subjecting the obtained bis(diethylamino)silane to a reflux reaction for 3 to 9 hours; after cooling, removing the byproduct lithium chloride through a solid-liquid separator to obtain a first solution;

[0038] S4: transferring the obtained first solution to a distiller, first reducing the pressure to 10-50 mm Hg to evaporate the alkane solvent; and then reducing the pressure to 1-5 mm Hg to evaporate the product bis(diethylamino)silane;

[0039] S5: The distilled product bis(diethylamino)silane is subjected to adsorption and filtration to obtain electronic grade bis(diethylamino)silane.

[0040] Embodiment 1

[0041] This embodiment provides a method for preparing electronic grade bis(diethylamino)silane, comprising the following steps:

[0042] (1) Under an inert atmosphere, 146 g (2 mol) of diethylamine and 700 mL of n-hexane solution were added to a 2 L reaction bottle, the system temperature was maintained at about -15°C, and 360 mL (0.9 mol) of 2.5 mol / L n-butyl lithium solution was added dropwise while stirring. After the addition was completed, the reaction system was heated to room temperature and stirred for 10 hours;

[0043] (2) 101 g (1 mol) of dichlorosilane was added dropwise to the reaction system, and the reaction temperature was maintained at about -20°C for 10 hours to obtain bis(diethylamino)silane;

[0044] (3) After the reaction system was heated to room temperature, the system temperature was maintained at not less than 60° C. under inert gas protection and heated under reflux for 4 hours. After cooling, the by-product lithium chloride was removed through a solid-liquid separator. After the reaction was completed, the reaction system was filtered, and then the pressure was reduced to 10 mm Hg to evaporate the alkane solvent, and then the pressure was reduced to 1 mm Hg to evaporate the product bis(diethylamino)silane. The fraction at 80° C. / 1 mm Hg was collected, which was the target compound bis(diethylamino)silane. 148.7 g of the product was obtained with a yield of 85% and a purity of 99.99%.

[0045] Embodiment 2

[0046] This embodiment provides a method for preparing electronic grade bis(diethylamino)silane, comprising the following steps:

[0047] (1) Under an inert atmosphere, 146 g (2 mol) of diethylamine and 700 mL of n-hexane solution were added to a 2 L reaction bottle, the system temperature was maintained at about -10°C, and 360 mL (0.9 mol) of 2.5 mol / L n-butyl lithium solution was added dropwise while stirring. After the addition was completed, the reaction system was heated to room temperature and stirred for 10 hours;

[0048] (2) 101 g (1 mol) of dichlorosilane was added dropwise to the above reaction system, and the reaction system temperature was maintained at about -25°C for 7 hours to obtain bis(diethylamino)silane;

[0049] (3) After the reaction system was heated to room temperature, the system temperature was maintained at not less than 60° C. under inert gas protection and heated under reflux for 6 hours. After cooling, the by-product lithium chloride was removed through a solid-liquid separator. After the reaction was completed, the reaction system was filtered, and then the pressure was reduced to 10 mm Hg to evaporate the alkane solvent, and then the pressure was reduced to 1 mm Hg to evaporate the product bis(diethylamino)silane. The fraction at 80° C. / 1 mm Hg was collected, which was the target compound bis(diethylamino)silane. 150.9 g of the product was obtained with a yield of 86.25% and a purity of 99.99%.

[0050] Comparative Example 1

[0051] A method for preparing bis(diethylamino)silane comprises the following steps:

[0052] (1) Under an inert atmosphere, 146 g (2 mol) of diethylamine and 700 mL of n-hexane solution were added to a 2 L reaction bottle, the system temperature was maintained at about -15°C, and 360 mL (0.9 mol) of 2.5 mol / L n-butyl lithium solution was added dropwise while stirring. After the addition was completed, the reaction system was heated to room temperature and stirred for 10 hours;

[0053] (2) 101 g (1 mol) of dichlorosilane was added dropwise to the above reaction system, and the reaction system temperature was maintained at about -20°C for 10 hours to obtain bis(diethylamino)silane. The product was 113.75 g with a yield of 65% and a purity of 91.89%.

[0054] Comparative Example 2

[0055] A method for preparing bis(diethylamino)silane comprises the following steps:

[0056] (1) Under an inert atmosphere, 146 g (2 mol) of diethylamine and 700 mL of n-hexane solution were added to a 2 L reaction bottle, the system temperature was maintained at about -15°C, and 360 mL (0.9 mol) of 2.5 mol / L n-butyl lithium solution was added dropwise while stirring. After the addition was completed, the reaction system was heated to room temperature and stirred for 10 hours;

[0057] (2) 101 g (1 mol) of dichlorosilane was added dropwise to the reaction system, and the reaction temperature was maintained at about -20°C for 10 hours to obtain bis(diethylamino)silane;

[0058] (3) After the reaction system was heated to room temperature, the system temperature was maintained at not less than 60° C. under inert gas protection and heated to reflux for 4 hours. After cooling, the by-product lithium chloride was removed through a solid-liquid separator. After the reaction was completed, the reaction system was filtered and separated to obtain bis(diethylamino)silane, and 131.2 g of the product was obtained with a yield of 75% and a purity of 95.95%.

[0059] The present application provides a method for preparing electronic-grade bis(diethylamino)silane, which additionally adopts a purification process on the original processing technology, firstly performs a reflux reaction, then performs multiple vacuum distillations, and finally performs adsorption and filtration, thereby greatly improving the purity of the product, so that the purity and particle size of the product both better meet the product requirements of the electronics industry; moreover, the method of the present invention only requires a single hydrocarbon solvent, and its raw materials are all conventional commercially available products, which reduces the synthesis cost and the toxicity of the reaction, has better operability, and is suitable for industrial application; the yield of the present invention is high, and it is easy to scale up production.

[0060] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing electronic grade bis(diethylamino)silane, characterized in that: The steps include: S1: under the protection of an inert atmosphere, diethylamine and a hydrocarbon solvent are added to a reactor, and then an organic lithium compound is added to the system, the temperature is controlled at -20°C to 0°C, and diethylamide lithium is obtained after reacting for several hours; S2: adding dichlorosilane to the system, controlling the temperature at -25°C to -15°C, reacting for several hours, filtering and distilling after the reaction to obtain bis(diethylamino)silane; S3: subjecting the obtained bis(diethylamino)silane to a reflux reaction for 3 to 9 hours; after cooling, removing the byproduct lithium chloride through a solid-liquid separator to obtain a first solution; S4: transferring the obtained first solution to a distiller, first reducing the pressure to 10-50 mm Hg to evaporate the alkane solvent; and then reducing the pressure to 1-5 mm Hg to evaporate the product bis(diethylamino)silane; S5: The distilled product bis(diethylamino)silane is subjected to adsorption and filtration to obtain electronic grade bis(diethylamino)silane.

2. The method for preparing electronic grade bis(diethylamino)silane according to claim 1, wherein: The hydrocarbon solvent is a normal alkane with 4 to 8 carbon atoms.

3. The method for preparing electronic grade bis(diethylamino)silane as claimed in claim 2, characterized in that: The hydrocarbon solvent is n-hexane.

4. The method for preparing electronic grade bis(diethylamino)silane according to claim 1, wherein: The organic lithium compound is a normal chain hydrocarbon lithium with 4 to 6 carbon atoms.

5. The method for preparing electronic grade bis(diethylamino)silane as claimed in claim 4, characterized in that: The n-chain alkyl lithium is n-butyl lithium.

6. The method for preparing electronic grade bis(diethylamino)silane according to claim 1, wherein In step S1, the temperature is -15°C and the reaction time is 10 hours; in step S2, the temperature is -20°C and the reaction time is 10 hours.

7. The method for preparing electronic grade bis(diethylamino)silane according to claim 1, characterized in that: In step S3, the reflux reaction time is 4 hours.

8. The method for preparing electronic grade bis(diethylamino)silane according to claim 1, wherein: In step S4, the decompression pressure is first reduced to 30 mm Hg, and then reduced to 3 mm Hg.

9. The method for preparing electronic grade bis(diethylamino)silane according to claim 1, wherein: During the reaction, the molar ratio of diethylamine to the organic lithium compound is 1-1.2:1, the molar ratio of the organic lithium compound to dichlorosilane is 4:1-1.2, and the inert atmosphere is a nitrogen atmosphere.

10. The method for preparing electronic grade bis(diethylamino)silane according to claim 9, characterized in that: The molar ratio of the diethylamine to the organic lithium compound is 1.1:1, and the molar ratio of the organic lithium compound to dichlorosilane is 4:1.1.

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