Device for preparing electronic-grade disilane through circulating pyrolytic reaction

Abstract

According to the preparation device of the electronic-grade disilane, high-order silane is generated on the basis of pyrolysis polymerization reaction of crude monosilane, after the high-order silane is primarily separated by the circulating tower, heavy components are rectified twice to remove light components and heavy components respectively, and then are purified twice to remove water, oxygen and metal ions to obtain the electronic-grade disilane, so that continuous production is realized, the production cost is reduced, and the production efficiency is improved. And common unit equipment combination can be directly used, so that the cost is low, the efficiency is high, and a new choice is provided for preparation of electronic-grade disilane.

Description

TECHNICAL FIELD

[0001] The utility model relates to the preparation technical field of silane, concretely is the device of preparation electronic grade disilane of cyclic pyrolysis reaction. BACKGROUND

[0002] With the rapid development of semiconductor very large scale integrated circuit, storage chip capacity and layer number, the demand for ultrahigh purity disilane used in the above-mentioned field manufacturing process is more and more large, in advanced process semiconductor manufacturing, electronic grade disilane can be used in chemical vapor deposition (CVD) and atomic layer deposition (ALD) process, to deposit high quality silicon thin film. These thin films play a key role in integrated circuits, such as as gate insulating layer of transistor, diffusion barrier layer of source and drain etc. Disilane has high reactivity and selectivity, can realize efficient deposition process at lower temperature, help to reduce energy consumption and thermal stress in chip manufacturing process, and improve production efficiency and chip performance. For example, in the chip manufacturing of 7 nanometer and below, disilane can be used to deposit very thin silicon germanium (SiGe) or silicon carbon (SiC) alloy thin film, to improve the performance and reliability of transistor. In addition, electronic grade disilane can be used as a doping source for semiconductor doping process. By introducing disilane in CVD or ion implantation process, the doping concentration and depth can be accurately controlled, so that the electrical properties of semiconductor materials can be regulated.

[0003] There are many preparation devices for electronic grade disilane, at present, the process is mainly in the process of producing silane by silicon-magnesium alloy method, through multistage separation, the obtained trace amount of disilane is purified, and electronic grade disilane is obtained, which needs to consume a large amount of liquid ammonia in the previous process, and the content of disilane obtained is small, which cannot meet the large-scale semiconductor industrialization demand. Secondly, through the method of electrocatalysis, the methylsilane in the reactor is discharged and ionized, the silicon-hydrogen bond is separated and combined to form silicon-silicon bond, and disilane is generated and then separated and purified. Thirdly, the organic catalytic conversion method of methylsilane: taking methylsilane as raw material, the reaction product including methylsilane, disilane and hydrogen is obtained in the fixed bed reactor through catalytic reaction, and disilane is obtained after a series of separation and purification. In this process, dimethyl titanium and platinum such as ethylene bis (triphenyl phosphine) are used as noble metal organic catalysts, and part of organic solvents are also used, and the reaction activity is difficult to control.

[0004] Therefore, it is necessary to propose a preparation device for electronic grade disilane to solve the defects of high cost and low efficiency of the existing device, which leads to unsuitable industrial production. INVENTION CONTENTS

[0005] The utility model proposes a kind of device for preparation electronic grade disilane of cyclic pyrolysis reaction, solves the defect of high cost and low efficiency of preparation device in prior art, which leads to unsuitable industrial production.

[0006] The technical scheme of the utility model is as follows:

[0007] The utility model provides a device for preparing electronic grade disilane by cyclic pyrolysis reaction, which comprises a preheating unit, a reactor, a filter, a circulating column, a rectifying column one and a rectifying column two, a purifier one and a purifier two which are sequentially connected, wherein:

[0008] The preheating unit is connected to the upper part of the reactor and is used for feeding and preheating silane; the lower part of the reactor is connected to the filter; the reactor is used for generating disilane through the pyrolysis polymerization reaction of silane;

[0009] The circulating column is used for pre-separating and removing silane; the rectifying column one and the rectifying column two are respectively used for removing light components and heavy components;

[0010] The purifier one is used for removing water and oxygen; and the purifier two is used for removing metal ions to obtain electronic grade disilane.

[0011] Further, the preheating unit comprises a preheater and a heater which are connected in series; the filter is connected to the heat exchange medium layer of the preheater;

[0012] Further, a cooler one is arranged between the filter and the circulating column.

[0013] Preferably, the filter is a plurality of filters which are arranged in parallel.

[0014] Further, the circulating column is provided with a circulating pipe at the top of the circulating column, the circulating pipe is connected to the preheating unit through a compressor.

[0015] Further, the circulating column is provided with a reflux pipe one at the top of the circulating column, the reflux pipe one is connected to the upper part of the circulating column, and the reflux pipe one is provided with a tapping pipe one for tapping non-condensable gas.

[0016] Further, the rectifying column one is provided with a reflux pipe two at the top of the rectifying column one, the reflux pipe two is connected to the upper part of the rectifying column one, and the reflux pipe two is provided with a tapping pipe two for tapping non-condensable gas.

[0017] Preferably, the tapping pipe two is connected to the feeding end of the circulating column.

[0018] Further, the purifier one is filled with metal oxides; and / or the purifier two is filled with metal cation exchange resins.

[0019] Further, a plurality of purifiers one and a plurality of purifiers two are arranged respectively and arranged in parallel.

[0020] Further, the reactor is provided with a packing layer, and the packing layer is filled with one or more of stainless steel Rasching rings, Pall rings or stepped rings.

[0021] Compared with the prior art, the electronic-grade disilane preparation device has the advantages that:

[0022] The electronic-grade disilane preparation device disclosed by the utility model is based on the pyrolytic polymerization reaction of crude monosilane to generate high-order silane, after preliminary separation through a circulating column, the heavy components are subjected to two rectifications for light component removal and heavy component removal respectively, and then are subjected to two purifications for removal of water, oxygen and metal ions respectively to obtain the electronic-grade disilane, continuous production is realized, common unit equipment combination can be directly used, the cost is low, the efficiency is high, and a new selection is provided for the preparation of the electronic-grade disilane. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical schemes in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0024] Figure 1 It is the schematic diagram of the device for preparing electronic-grade disilane through the circulating pyrolysis reaction.

[0025] Figure 1 The reference signs in the drawings are as follows:

[0026] 100, reflux pipe one; 101, circulating pipe; 200, reflux pipe two; L1, production pipe one; L2, production pipe two; C1, compressor; E1, preheater; E2, electric heater; E3, cooler one; E4, cooler two; E5, cooler three; E6, cooler four; F1, filter; P1, pump one; P2, pump two; P3, pump three; P4, pump four; P5, pump five; R1, reactor; FT1, circulating column; T1, rectification column one; T2, rectification column two; V1, storage tank one; V2, storage tank two; A1, purifier one; A2, purifier two. DETAILED DESCRIPTION

[0027] The technical scheme of the utility model will be described clearly and completely in combination with the embodiments of the utility model, obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0028] REFERENCE Figure 1In one embodiment, a device for preparing electronic-grade disilane by cyclic pyrolysis reaction is provided, which comprises, in sequence, a preheating unit, a reactor R1, a filter F1, a circulating column FT1, a distillation column T1 and a distillation column T2, a purifier A1 and a purifier A2; wherein:

[0029] The preheating unit is connected to the upper part of the reactor R1 for feeding and preheating of silane; the lower part of the reactor R1 is connected to the filter F1; the reactor R1 is used for the pyrolysis polymerization reaction of silane to generate disilane;

[0030] The circulating column FT1 is used for pre-separation to remove silane; the distillation column T1 and the distillation column T2 are used for removing light components and heavy components, respectively; the light components include hydrogen, silane, nitrogen, methane and carbon monoxide; the heavy components include chlorosilane and water;

[0031] The purifier A1 is used for removing water and oxygen; the purifier A2 is used for removing metal ions to obtain electronic-grade disilane.

[0032] In the above embodiment, the preparation device can generate high-order silane based on the pyrolysis polymerization reaction of crude silane; after preliminary separation by the circulating column, the heavy components are subjected to two times of distillation to remove light components and heavy components, respectively; and then the two times of purification are performed to remove water, oxygen and metal ions to obtain electronic-grade disilane, thereby realizing continuous production; the raw material can be crude silane by-produced from electronic-grade silane; common unit equipment can be directly used; the economic benefit is high; and a new choice is provided for the preparation of electronic-grade disilane.

[0033] In a preferred embodiment, the preheating unit comprises a preheater E1 and a heater E2 connected in series; the filter F1 is connected to the heat exchange medium layer of the preheater E1; the hot material after reaction is used for preheating the feed in the preheater E1 after filtration, thereby improving the heat utilization efficiency.

[0034] In a preferred embodiment, the filter F1 is provided in multiple parallel connections for maintenance and switching use, thereby ensuring continuous operation of the system. A cooler E3 is provided between the filter F1 and the circulating column FT1, which is preferably connected in series with the above-mentioned preheater E1, for cooling the material to an appropriate temperature to enter the circulating column FT1 for separation.

[0035] In a preferred embodiment, the reactor R1 is filled with stainless steel Raschig rings, Pall rings, stepped rings and other types of random packings, thereby increasing the reaction area of silane in the reactor; silane is pyrolyzed by silicon-hydrogen bond in the reactor R1, and the silicon-silicon bond is polymerized to generate disilane, trisilane or higher-order silane.

[0036] In the preferred embodiment, the top of the circulating column FT1 is provided with a circulation pipe 101 connected to the preheating unit via a compressor C1. The top of the circulating column FT1 is provided with a reflux pipe one 100 connected to the upper part of the circulating column FT1 for circulating feed to improve the utilization of silane and further improve the yield of disilane; the reflux pipe one 100 is provided with a production pipe one L1 for producing non-condensable gas. Specifically, the reflux pipe one 100 is provided with a cooler two E4, a storage tank one V1, and a pump two P2 from the top of the circulating column FT1 to the reflux feed end in sequence for reflux at the top and power supply; the material outlet end of the cooler two E4 is also provided with an upward extension pipeline connected to a cooler three E5, and the outlet end of the cooler three E5 is provided with the production pipe one L1 for condensing and producing non-condensable gas to the external tail gas absorption system.

[0037] In the preferred embodiment, the top of the rectifying column one T1 is provided with a reflux pipe two 200 connected to the upper part of the rectifying column one T1 via a cooler four E6; the material output end of the cooler four E6 is provided with a production pipe two L2 for producing non-condensable gas, including non-condensable silane. The production pipe two L2 is connected to the feed end of the circulating column FT1 for circulating feed to improve the recovery rate.

[0038] In the above embodiment, the light components are circulated to the reactor through the top of the circulating column, and the non-condensable components are circulated to the circulating column through the top of the rectifying column one, and the above multi-circulation mode can effectively improve the yield of disilane prepared by pyrolysis polymerization, further reduce the preparation cost, and is suitable for industrial application.

[0039] In the preferred embodiment, the purifier one A1 is filled with metal oxides such as γ-Al2O3, which can further remove water and oxygen; the purifier two A2 is filled with metal cation exchange resin such as alkali metal (sodium / potassium) styrene cation exchange resin, which further removes metal ions. The purifier one A1 and the purifier two A2 are respectively provided with multiple parallel connections for maintenance and switching use to ensure continuous operation of the system.

[0040] In some embodiments, the circulating column FT1 is provided with an electric heating system (not shown in the figure) to provide heat source for the column reboiler by heating the heat conducting oil in the shell side. The pump one P1 is used to circulate the heat conducting oil in the shell side to increase the heat exchange efficiency. Similarly, the column reboilers of the rectifying column one T1 and the rectifying column two T2 are also provided with electric heating systems (not shown in the figure) to provide heat source for the column reboiler by heating the heat conducting oil in the shell side respectively. The pump three 3 and the pump four P4 are used to circulate the heat conducting oil in the shell side to increase the heat exchange efficiency. The output end of the purifier two A2 is connected to the storage tank two V2 and the pump five P5 for pressurization after filling, and then enters the subsequent analysis and filling system as the final ultra-high purity disilane product for semiconductors.

[0041] As a routine setting in the art, the above device further comprises a power pump for providing material transfer, a valve for pipeline control, and instruments for monitoring working conditions, which are not described herein.

[0042] The above device is used in the process for preparing electronic-grade disilane as follows:

[0043] 1) The crude monosilane by-produced from electronic-grade silane is preheated by a preheater E1 and then enters an electric heater E2, in which the temperature is heated to 380-450°C. After heating, the gas enters a reactor R1. The monosilane is pyrolyzed by a silicon-hydrogen bond and polymerized by a silicon-silicon bond in the reactor R1 to generate disilane, trisilane or higher-order silane.

[0044] 2) The product obtained by the reaction in the reactor R1 is first filtered by a filter F1 to remove the micro-silicon powder possibly generated by the pyrolysis of monosilane during the reaction. The gas from the filter F1 enters the preheater E1, in which the raw material gas is preheated and the temperature of the gas itself is reduced. The gas from the preheater E1 enters a cooler one E3, in which the temperature of the gas is reduced to a suitable separation temperature by circulating water.

[0045] 3) The gas cooled by the cooler one E3 enters a circulating tower FT1. Part of the gas at the top of the tower is pressurized by a circulating compressor C1 through a circulating pipe 101 and then returned to the raw material pipeline of the crude monosilane to enter the preheater E1 as the circulating reaction gas. Another part of the gas is condensed to a lower temperature by a cooler two E4 and a cooler three E5 in sequence through a reflux pipe 100. The non-condensable gas is discharged to a tail gas absorption system through a production pipe one L1. The condensate is output from the output end of the cooler two E4 to enter a storage tank one V1 and then pumped by a pump two P2 to be returned to the upper part of the circulating tower FT1 as the reflux liquid.

[0046] 4) The material mainly containing disilane collected from the tower kettle of the circulating tower FT1 is treated by a light-removing distillation column one T1. The distillation column one T1 mainly removes hydrogen, monosilane, nitrogen, methane, carbon monoxide and other substances contained in the disilane. The gas containing non-condensable silane is returned to the circulating tower FT1 for recycling after being condensed by a cooler four E6. The condensate is returned to the upper part of the distillation column one T1 as the reflux liquid.

[0047] 5) The disilane after removing the light components collected from the tower kettle of the distillation column one T1 is treated by a heavy-removing distillation column two T2. The distillation column two T2 mainly removes chlorosilane, moisture and other impurities contained in the disilane.

[0048] 6) The light components taken out from the top of the rectification column two T2 enter the purifier one A1 filled with metal oxide, and the water, oxygen and other impurities not removed in the rectification system are deeply removed, so that the water content and oxygen content are reduced to below 10ppb. The product after deep dehydration enters the purifier two A2 filled with metal cation exchange resin, and the metal ion content in the material is removed to below 10ppt. The material after removal of metal ions is the electronic grade ethylsilane.

[0049] In the above embodiment, the ethylsilane finally obtained by the preparation device is analyzed, and the propylsilane, hydrogen, methylsilane, nitrogen, methane, carbon monoxide, chlorosilane, moisture and metal ion are all controlled within the impurity control range of the electronic grade, the purity of the ethylsilane reaches more than 6N, and reaches the standard requirement of the electronic grade.

[0050] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. Apparatus for the production of electronic grade disilane by a cyclic pyrolysis reaction, characterised in that, The preheating unit, the reactor (R1), the filter (F1), the circulating column (FT1), the rectifying column one (T1) and the rectifying column two (T2), the purifier one (A1) and the purifier two (A2) are sequentially connected; wherein: The preheating unit is connected to the upper part of the reactor (R1) for feeding and preheating of silane; the lower part of the reactor (R1) is connected to the filter (F1); the reactor (R1) is used for pyrolytic polymerization of silane to generate disilane; The circulating column (FT1) is used for pre-separation of silane; the rectifying column one (T1) and the rectifying column two (T2) are respectively used for light removal and heavy removal; The purifier one (A1) is used for removing water and oxygen; the purifier two (A2) is used for removing metal ions to obtain electronic-grade disilane.

2. The apparatus for cyclic pyrolytic reaction for producing electronic grade disilane as claimed in claim 1, wherein, The preheating unit comprises a preheater (E1) and a heater (E2) connected in series; the filter (F1) is connected to the heat exchange medium layer of the preheater (E1); And / or, a cooler one (E3) is arranged between the filter (F1) and the circulating column (FT1).

3. The apparatus for cyclic pyrolytic reaction production of electronic grade disilane as claimed in claim 2, wherein, The filter (F1) is multiple and arranged in parallel.

4. The apparatus for cyclic pyrolytic reaction for producing electronic grade disilane as claimed in claim 1, wherein, The circulating column (FT1) is provided with a circulating pipe (101) connected to the preheating unit through a compressor (C1).

5. The apparatus for cyclic pyrolytic reaction for producing electronic grade disilane as claimed in claim 1 or 4, wherein The circulating column (FT1) is provided with a reflux pipe one (100) connected to the upper part of the circulating column (FT1), and the reflux pipe one (100) is provided with a production pipe one (L1) for producing non-condensable gas.

6. The apparatus for cyclic pyrolytic reaction production of electronic grade disilane as claimed in claim 1, wherein, The rectifying column one (T1) is provided with a reflux pipe two (200) connected to the upper part of the rectifying column one (T1); the reflux pipe two (200) is provided with a production pipe two (L2) for producing non-condensable gas.

7. The apparatus for cyclic pyrolytic reaction production of electronic grade disilane as claimed in claim 6, wherein The production pipe two (L2) is connected to the feeding end of the circulating column (FT1).

8. The apparatus for cyclic pyrolytic reaction for producing electron grade disilane as claimed in claim 1, wherein The purifier one (A1) is filled with metal oxide; and / or, the purifier two (A2) is filled with metal cation exchange resin.

9. The apparatus for cyclic pyrolytic reaction production of electronic grade disilane as claimed in claim 1 or 8, wherein The purifier one (A1) and the purifier two (A2) are respectively provided with multiple and arranged in parallel.

10. The apparatus for cyclic pyrolytic reaction for producing electron grade disilane as claimed in claim 1, wherein The reactor (R1) is provided with a filler layer filled with one or more of stainless steel Rasching ring, Pall ring or stepped ring.

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