JP2818780B2 - Polymer removal in polycrystalline silicon production. - Google Patents
Polymer removal in polycrystalline silicon production.Info
- Publication number
- JP2818780B2 JP2818780B2 JP8519490A JP8519490A JP2818780B2 JP 2818780 B2 JP2818780 B2 JP 2818780B2 JP 8519490 A JP8519490 A JP 8519490A JP 8519490 A JP8519490 A JP 8519490A JP 2818780 B2 JP2818780 B2 JP 2818780B2
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- Prior art keywords
- polymer
- pipe
- chlorosilane
- polycrystalline silicon
- gas
- Prior art date
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、トリクロルシラン（SiHCl3）を原料として
多結晶シリコンを製造する際に、その排ガス経路に凝縮
付着するポリマーの除去法に関する。Description: TECHNICAL FIELD The present invention relates to a method for removing a polymer that is condensed and attached to an exhaust gas path when producing polycrystalline silicon using trichlorosilane (SiHCl 3 ) as a raw material.
〔従来の技術〕 従来より、半導体製造用の多結晶シリコンは、ベルジ
ャー炉内で約1000〜1100℃に加熱保持されたシリコン芯
棒にSiHCl3とH2の混合ガスを接触させてSiを析出させる
ことにより製造される。このとき、SiHCl3は第１式に示
す水素還元反応と、通常は更に第２式に示す熱分解反応
とでSiに分解される。[Prior art] Conventionally, polycrystalline silicon for semiconductor production has deposited Si by contacting a mixed gas of SiHCl 3 and H 2 with a silicon core rod heated and held at about 1000 to 1100 ° C in a bell jar furnace. It is manufactured by having At this time, SiHCl 3 is decomposed into Si by a hydrogen reduction reaction represented by the first formula and usually further by a thermal decomposition reaction represented by the second formula.
SiHCl3＋H2→Si＋3HCl …（１） 4SiHCl3→Si＋3SiCl4＋2H …（２） また、物質収支は、反応条件にもよるが、工業的には
大概次のとおりである。SiHCl 3 + H 2 → Si + 3HCl (1) 4SiHCl 3 → Si + 3SiCl 4 + 2H (2) The material balance depends on the reaction conditions, but is industrially as follows.
すなわち、ベルジャー炉内では、送入されたガス状の
SiHCl3からSiが生成される他、残余のSiHCl3を生じ、更
にSiH2Cl2、SiCl4、ポリマー等の副生物が生じる。これ
らは、炉外へ排ガスとして排出される。 In other words, in the bell jar furnace,
In addition to producing Si from SiHCl 3 , residual SiHCl 3 is produced, and by-products such as SiH 2 Cl 2 , SiCl 4 and polymers are produced. These are discharged as flue gas outside the furnace.
ベルジャー炉から排出される排ガスに含まれるポリマ
ーは、Si,H,Clの成分からなるが、定まった組織ではな
い。このポリマーは、高沸点の物質であるために、ベル
ジャー炉から排出されて温度が低下するに従い粘性が増
大し、排ガスの通流する炉内ガス排出管の内部や、排ガ
スから未反応のトリクロルシラン等の原料ガスを回収す
るために設けた熱交換器の配管内に一部が凝縮付着され
る。配管内に付着するポリマーを放置すると、多結晶シ
リコン製造回数を重ねるに連れて、配管内に凝縮付着す
るポリマーの量が多くなり、配管の詰まりや、熱交換器
においてはポリマー付着箇所での伝熱不良等を生じる。The polymer contained in the exhaust gas discharged from the bell jar furnace is composed of components of Si, H and Cl, but has no defined structure. Since this polymer is a substance with a high boiling point, its viscosity increases as it is discharged from the bell jar furnace and the temperature decreases, and unreacted trichlorosilane is discharged from the inside of the furnace gas discharge pipe through which the exhaust gas flows and from the exhaust gas. Part of the gas is condensed and attached to the pipes of the heat exchanger provided for recovering the raw material gas. If the polymer adhering to the pipe is left untreated, the amount of polymer condensing and adhering to the pipe increases as the number of times of production of polycrystalline silicon increases, causing clogging of the pipe and transfer of the polymer at the polymer adhering point in the heat exchanger. Heat failure or the like occurs.
配管内に付着したポリマーの除去法としては、従来
は、ポリマーの付着している炉内ガス排出管や熱交換器
を分解してスケール等で配管内よりポリマーを掻き出す
人手による方法と、配管内に酸性の液を通流させ、化学
反応により付着ポリマーの組成を変えて、これを除去す
る化学的方法とが実施されている。Conventionally, there are two methods for removing the polymer adhering to the piping: a manual method of disassembling the gas exhaust pipe or heat exchanger in the furnace to which the polymer is adhering and scraping the polymer out of the piping using a scale or the like. And a chemical method of changing the composition of the deposited polymer by a chemical reaction and removing the same.
しかるに、ポリマーは空気中で発火しやすく、その取
り扱いに苦慮する物質であるために、人手による方法で
は、配管を開放した際にポリマーが発火するおそれがあ
り、安全上大きな問題がある。However, since the polymer easily ignites in the air and is a substance that is difficult to handle, there is a risk that the polymer may ignite when the pipe is opened by a manual method, and there is a major safety problem.
これに対し、化学的な除去方法は、配管を開放する必
要がない。しかし、ここで使用される酸性の液は弗酸と
硝酸との混酸であり、配管自体を浸食させて穴があくな
どの弊害を生じる危険性がある。また、酸性の液に含ま
れる微量のリン，ボロン等によって配管内が汚染され、
多結晶シリコンの品質を低下させる危険性もある。In contrast, the chemical removal method does not require opening the piping. However, the acidic liquid used here is a mixed acid of hydrofluoric acid and nitric acid, and there is a danger that the piping itself will be eroded to cause adverse effects such as holes. In addition, the inside of the pipe is contaminated by trace amounts of phosphorus, boron, etc. contained in the acidic liquid,
There is also a risk of degrading the quality of the polycrystalline silicon.
なお、NaOH等のアルカリ水溶液を配管内に通流させれ
ば、配管内のポリマーが除去されることは知られている
が、水などを配管内に流入させて配管内に残留するアル
カリ水溶液を除去せねばならず、作業効率が悪い。ま
た、洗浄とは別に、アルカリ水溶液とポリマーの反応で
はH2Oが発生し、このH2Oが配管内に残留したまま多結晶
シリコンの製造を行うとSiO2（シリカ）等の副産物が生
成し、これが新たな配管詰まりの原因となるため、H2O
が配管内に残留しないよう配管内を十分に乾燥しなけれ
ばならない等の問題もある。そのため、アルカリ水溶液
による除去は、実際には殆ど行われていない。It is known that if an alkaline aqueous solution such as NaOH is passed through the piping, the polymer in the piping is removed.However, water or the like flows into the piping to remove the alkaline aqueous solution remaining in the piping. It has to be removed and the work efficiency is poor. In addition to the cleaning by-products such as H 2 O is generated by the reaction of an alkaline aqueous solution and the polymer, the H 2 when O is to manufacture remains polycrystalline silicon remaining in the pipe SiO 2 (silica) product since then, this causes new pipe clogging, H 2 O
There is also a problem that the inside of the pipe must be sufficiently dried so as not to remain in the pipe. For this reason, removal with an alkaline aqueous solution is hardly performed in practice.
一方、排ガスと共に系外に排出されたポリマーは、分
離回収してトリクロルシランの製造原料になり得ること
が特開平１−188414号公報に開示されており、配管内か
ら除去されたポリマーについても、トリクロルシランの
製造原料としての再利用が期待できる。ところが、従来
の化学的な方法でポリマーを除去すると、除去されたポ
リマーに弗素やナトリウム等が含有されてしまい、再利
用が困難になるという問題もある。On the other hand, it is disclosed in JP-A-1-188414 that the polymer discharged out of the system together with the exhaust gas can be separated and recovered to be a raw material for producing trichlorosilane, and the polymer removed from the piping is also disclosed. It can be expected to reuse trichlorosilane as a raw material. However, when the polymer is removed by a conventional chemical method, there is a problem that the removed polymer contains fluorine, sodium, and the like, and it is difficult to reuse the polymer.
本発明は斯かる事情に鑑みなされたものであり、その
目的は、多結晶シリコン製造装置の排ガス経路には付着
残留するポリマーを人手によらずに除去し、しかも配管
の浸食や汚染の危険性がないポリマー除去法を提供する
ことにある。The present invention has been made in view of such circumstances, and an object of the present invention is to remove a polymer adhering and remaining in an exhaust gas path of a polycrystalline silicon manufacturing apparatus without manual operation, and furthermore, there is a danger of erosion and contamination of piping. The object of the present invention is to provide a method for removing the polymer.
本発明のポリマー除去法は、トリクロルシランを水素
ガスで還元して多結晶シリコンを製造する際に副生した
凝縮ポリマーを、クロルシランにより溶解して除去する
ことを特徴としてなる。The polymer removal method of the present invention is characterized by dissolving and removing condensed polymer by-produced when producing polycrystalline silicon by reducing trichlorosilane with hydrogen gas.
多結晶シリコンの製造に際して副生した凝縮ポリマー
は、クロルシランの液体に特定の溶解度をもって溶解さ
れ、液体の温度が高いほど溶解反応は促進される。クロ
ルシランが気体の場合には、ポリマーに接触するクロル
シランが少なく、液体の場合ほどにはポリマーが溶解さ
れない。Condensed polymer by-produced during the production of polycrystalline silicon is dissolved in chlorosilane liquid with a specific solubility, and the higher the temperature of the liquid, the more the dissolution reaction is promoted. When the chlorosilane is gaseous, the chlorosilane in contact with the polymer is small, and the polymer is not dissolved as much as in the case of a liquid.
本発明のポリマー除去法に使用されるクロルシランと
しては、常温で液体状態になる高沸点のクロルシラン
（SiCl4,SiHCl3,Si2Cl2等）が特に適している。As the chlorosilane used in the polymer removing method of the present invention, chlorosilane having a high boiling point (SiCl 4 , SiHCl 3 , Si 2 Cl 2, etc.) which is in a liquid state at normal temperature is particularly suitable.
例えば、SiCl4は沸点が57℃であり、少量の加熱を加
えるだけで容易にガス化され、そのガスを多結晶シリコ
ン製造装置における排ガス経路の配管内に注入すれば、
配管内に広く行きわたり、しかも常温の配管内で冷却さ
れて配管内面に凝縮される。その結果、配管内に付着す
るポリマーがクロルシラン、特にその沸点直下の比較的
高温のクロルシラン液により活発に溶解される。For example, SiCl 4 has a boiling point of 57 ° C., is easily gasified by adding a small amount of heating, and if the gas is injected into a pipe of an exhaust gas path in a polycrystalline silicon manufacturing apparatus,
It spreads widely in the pipe, and is cooled in the pipe at room temperature and condensed on the inner surface of the pipe. As a result, the polymer adhering in the pipe is actively dissolved by chlorosilane, particularly chlorosilane liquid having a relatively high temperature just below its boiling point.
これに対し、常温で気体状態である低沸点のクロルシ
ラン（SiCl2H2等）の場合は、ガス化設備を必要としな
い反面、そのガスを常温の配管内に注入しても液化が起
こり難く、クロルシラン液による高効率な溶解除去を期
待しようとすると、クロルシランの沸点以下の温度にま
で配管等を冷却する必要がある。また、たとえ冷却を行
ってもクロルシラン液の温度が低いので、高沸点のクロ
ルシランほどには溶解は促進されない。On the other hand, in the case of chlorosilane (SiCl 2 H 2 etc.) having a low boiling point which is in a gaseous state at room temperature, gasification equipment is not required, but liquefaction hardly occurs even if the gas is injected into a pipe at room temperature. In order to expect highly efficient dissolution and removal with a chlorosilane solution, it is necessary to cool pipes and the like to a temperature lower than the boiling point of chlorosilane. Further, even if cooling is performed, the temperature of the chlorosilane liquid is low, so that the dissolution is not promoted as much as chlorosilane having a high boiling point.
なお、クロルシランを液体状態で直接使用する場合
は、必要以上に多量のクロルシランが必要になる。ま
た、クロルシランの取り扱いが大掛かりとなり、圧力調
整等のコントロールも難しい。When chlorosilane is used directly in a liquid state, an unnecessarily large amount of chlorosilane is required. Further, the handling of chlorosilane becomes large, and it is difficult to control such as pressure adjustment.
以上の理由から、常温で液体状態である高沸点のクロ
ルシランが溶解効率の面からも、また取り扱い性、経済
性の面からも優れている。For the above reasons, chlorosilane having a high boiling point, which is in a liquid state at normal temperature, is excellent in terms of dissolution efficiency, handling properties, and economy.
本発明のポリマー除去法によれば、多結晶シリコン製
造装置における排ガス経路にクロルシランを注入するだ
けでポリマーが溶解除去される。According to the polymer removing method of the present invention, the polymer is dissolved and removed only by injecting chlorosilane into the exhaust gas path in the polycrystalline silicon manufacturing apparatus.
特に、常温で液体状態である高沸点のクロルシランの
場合は、排ガス経路の配管内にクロルシランを注入すれ
ば、その配管内全体にクロルシランが行き渡り、しかも
配管内でクロルシランが配管内面上に凝縮液化すること
により、配管内面に付着するポリマーが比較的高温のク
ロルシラン液によって活発に溶解される。In particular, in the case of chlorosilane having a high boiling point which is in a liquid state at normal temperature, if chlorosilane is injected into the pipe of the exhaust gas path, the chlorosilane spreads throughout the pipe, and chlorosilane is condensed and liquefied on the pipe inner surface in the pipe. Thereby, the polymer adhering to the inner surface of the pipe is actively dissolved by the chlorosilane liquid having a relatively high temperature.
クロルシランは多結晶シリコンの製造原料であり、多
結晶シリコン製造装置における排ガス経路に注入されて
もその配管を浸食するおそれがなく、溶解除去されたポ
リマーを汚染するおそれもない。従って、溶解除去され
たポリマーをトリクロロシランの製造原料として直接再
利用できる。更に、配管を汚染する危険性も無論なく、
多結晶シリコンの製造に悪影響が生じない。Chlorosilane is a raw material for producing polycrystalline silicon. Even if it is injected into an exhaust gas path in a polycrystalline silicon production apparatus, there is no risk of eroding the piping and contaminating the dissolved and removed polymer. Therefore, the polymer removed by dissolution can be directly reused as a raw material for producing trichlorosilane. Furthermore, of course, there is no danger of polluting the piping,
There is no adverse effect on the production of polycrystalline silicon.
以下に本発明の実施例を説明する。 Hereinafter, embodiments of the present invention will be described.
第１図は本発明を実施すべく改良した多結晶シリコン
製造装置の排ガス系路を示す模式図である。装置稼働中
は、ベルジャー炉１内にSiHCl3とH2との混合ガスが送給
されて炉内のSi棒２を成長させる。炉内ガスは、ガス排
出管３を通じて炉外の熱交換器４に送られる。熱交換器
４で凝縮された排ガス中のSiHCl3,SiCl4等は回収容器５
に収容され、SiHCl3製造装置７に送られる。熱交換器４
で凝縮されなかったH2等のガスはH2精製装置に送られ
る。FIG. 1 is a schematic diagram showing an exhaust gas passage of a polycrystalline silicon manufacturing apparatus improved to carry out the present invention. During operation of the apparatus, a mixed gas of SiHCl 3 and H 2 is supplied into the bell jar furnace 1 to grow Si rods 2 in the furnace. The gas in the furnace is sent to a heat exchanger 4 outside the furnace through a gas discharge pipe 3. SiHCl 3 , SiCl 4, etc. in the exhaust gas condensed in the heat exchanger 4 are collected in a recovery vessel 5.
And sent to the SiHCl 3 production apparatus 7. Heat exchanger 4
The gas such as H 2 not condensed in is sent to the H 2 purifier.
多結晶シリコン製造装置が稼働を繰り返すにつれてガ
ス排出管３の内部や熱交換器４の配管内にポリマーが付
着して来る。操業に支障が出る程度にポリマーが付着す
ると、ガス排気管３および熱交換器４を常温に冷却した
状態で、液体のSiCl4を蒸発器６に送り、SiCl4を蒸発さ
せてそのガスをクロルシラン供給管８を通じてガス排出
管３内上流端より注入する。注入されたガス状のSiCl3
はガス排出管３内を通流する過程で冷却され、管内面上
に凝縮液化される。ガス排出管３の内面に付着している
ポリマーは、この凝縮液化した液体のSiCl4によって溶
解される。溶解ポリマーを含むSiCl4は、回収容器５に
収容され、SiHCl3製造装置７に送られる。As the operation of the polycrystalline silicon manufacturing apparatus is repeated, the polymer adheres to the inside of the gas discharge pipe 3 and the pipe of the heat exchanger 4. When the polymer adheres to such an extent that the operation is not hindered, the liquid SiCl 4 is sent to the evaporator 6 while the gas exhaust pipe 3 and the heat exchanger 4 are cooled to room temperature, and the SiCl 4 is evaporated to remove the gas from chlorosilane. The gas is injected from the upstream end inside the gas discharge pipe 3 through the supply pipe 8. Injected gaseous SiCl 3
Is cooled in the process of flowing through the gas discharge pipe 3 and condensed and liquefied on the inner surface of the pipe. The polymer adhering to the inner surface of the gas discharge pipe 3 is dissolved by the condensed and liquefied liquid SiCl 4 . The SiCl 4 containing the dissolved polymer is accommodated in the recovery container 5 and sent to the SiHCl 3 production device 7.
ベルジャー炉内ガスを炉外に排出するガス排出管内に
SiCl4の蒸気を約1kg凝縮させ、回収液を分留したとこ
ろ、82wt％のポリマーが溶解していることが確認され
た。また、炉内ガスを冷却する熱交換器の伝熱効率が、
10回の操業で約30％悪化したので、その時点で、熱交換
器の配管内をガス状のSiCl4で凝縮洗浄した。SiCl4の凝
縮量は300g/cm2とした。その結果、熱交換器の能力はほ
ぼ100％まで回復した。In the gas discharge pipe that discharges the bell jar furnace gas outside the furnace
When about 1 kg of SiCl 4 vapor was condensed and the recovered liquid was fractionated, it was confirmed that 82 wt% of the polymer was dissolved. In addition, the heat transfer efficiency of the heat exchanger that cools the furnace gas,
Since the operation deteriorated by about 30% after 10 operations, the pipes of the heat exchanger were condensed and washed with gaseous SiCl 4 at that time. The amount of SiCl 4 condensed was 300 g / cm 2 . As a result, the heat exchanger capacity was restored to almost 100%.
なお、上記実施例は、炉内ガス排出管、熱交換器配管
に付着するポリマーの除去について述べたが、ベルジャ
ー炉内に付着するポリマーが多い時には、ベルジャー炉
内にクロルシランガスを流入させてそのポリマーを除去
することもできる。In the above-described embodiment, the removal of the polymer adhering to the furnace gas exhaust pipe and the heat exchanger pipe has been described.However, when the amount of the polymer adhering to the bell jar furnace is large, the chlorosilane gas is caused to flow into the bell jar furnace to remove the polymer. The polymer can also be removed.
以上の説明から明らかなように、本発明のポリ 以上の説明から明らかなように、本発明のポリマー除
去法は、ポリマーを人手によらずに溶解除去するので、
ポリマーが配管内に付着する場合も、その配管を開放す
る必要がなく、作業性および安全性に優れる。しかも、
ポリマーが付着する配管等に損傷や汚染を発生させる危
険性が全くなく、さらに溶解除去されたポリマー自体も
汚染の危険がない。従って、除去されたポリマーをトリ
クロロシランの製造原料としてそのまま使用することが
できる。As is clear from the above description, the poly of the present invention As is clear from the above description, the polymer removing method of the present invention dissolves and removes the polymer without manual operation,
Even when the polymer adheres to the inside of the pipe, there is no need to open the pipe, and the workability and safety are excellent. Moreover,
There is no danger of causing damage or contamination to piping or the like to which the polymer adheres, and further, there is no danger of contamination of the polymer itself dissolved and removed. Therefore, the removed polymer can be used as it is as a raw material for producing trichlorosilane.
第１図は本発明のポリマー除去法の実施に適するように
改良を加えた多結晶シリコン製造装置の排ガス処理系を
示す系統図である。 1:ベルジャー炉、3:ガス排出管、4:熱交換器、5:回収容
器、6:蒸発器、7:SiHCl3製造装置、8:クロルシラン供給
管。FIG. 1 is a system diagram showing an exhaust gas treatment system of a polycrystalline silicon production apparatus improved so as to be suitable for carrying out the polymer removing method of the present invention. 1: bell jar furnace, 3: gas exhaust pipe, 4: heat exchanger, 5: recovery vessel, 6: evaporator, 7: SiHCl 3 production equipment, 8: chlorosilane supply pipe.
Claims (1)
結晶シリコンを製造する際に副生した凝縮ポリマーを、
クロルシランにより溶解して除去することを特徴とする
多結晶シリコンの製造におけるポリマー除去法。1. A condensation polymer by-produced in producing polycrystalline silicon by reducing trichlorosilane with hydrogen gas,
A method for removing a polymer in the production of polycrystalline silicon, characterized by dissolving and removing with chlorosilane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8519490A JP2818780B2 (en) | 1990-03-30 | 1990-03-30 | Polymer removal in polycrystalline silicon production. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8519490A JP2818780B2 (en) | 1990-03-30 | 1990-03-30 | Polymer removal in polycrystalline silicon production. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03285811A JPH03285811A (en) | 1991-12-17 |
| JP2818780B2 true JP2818780B2 (en) | 1998-10-30 |
Family
ID=13851840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8519490A Expired - Lifetime JP2818780B2 (en) | 1990-03-30 | 1990-03-30 | Polymer removal in polycrystalline silicon production. |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2818780B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2105409A1 (en) | 2008-03-28 | 2009-09-30 | Mitsubishi Materials Corporation | Polymer inactivation method for polycrystalline silicon manufacturing device |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102755975B (en) * | 2011-04-25 | 2014-11-19 | 中国科学院微电子研究所 | Method for avoiding pollution of oxidation furnace pipe |
| JP6506485B2 (en) * | 2017-01-16 | 2019-04-24 | 株式会社トクヤマ | Method of manufacturing polycrystalline silicon |
| JP2023007235A (en) | 2021-07-01 | 2023-01-18 | 信越化学工業株式会社 | Washing system, and washing method |
-
1990
- 1990-03-30 JP JP8519490A patent/JP2818780B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2105409A1 (en) | 2008-03-28 | 2009-09-30 | Mitsubishi Materials Corporation | Polymer inactivation method for polycrystalline silicon manufacturing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03285811A (en) | 1991-12-17 |
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