JPS62292613A - Method for purifying high purity silicon - Google Patents
Method for purifying high purity siliconInfo
- Publication number
- JPS62292613A JPS62292613A JP13287486A JP13287486A JPS62292613A JP S62292613 A JPS62292613 A JP S62292613A JP 13287486 A JP13287486 A JP 13287486A JP 13287486 A JP13287486 A JP 13287486A JP S62292613 A JPS62292613 A JP S62292613A
- Authority
- JP
- Japan
- Prior art keywords
- silicon
- carbon
- molten
- capture
- impurities
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 65
- 239000010703 silicon Substances 0.000 title claims abstract description 65
- 238000000034 method Methods 0.000 title claims description 27
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 45
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000012535 impurity Substances 0.000 claims abstract description 20
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 15
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 66
- 230000008018 melting Effects 0.000 claims description 10
- 238000002844 melting Methods 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 9
- 229910052581 Si3N4 Inorganic materials 0.000 abstract description 3
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 abstract description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 22
- 239000000377 silicon dioxide Substances 0.000 description 11
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000009489 vacuum treatment Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 239000000155 melt Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- 229920006395 saturated elastomer Polymers 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 229910002090 carbon oxide Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 125000004430 oxygen atom Chemical group O* 0.000 description 2
- 238000011946 reduction process Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- -1 aluminum Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- ZDHXKXAHOVTTAH-UHFFFAOYSA-N trichlorosilane Chemical compound Cl[SiH](Cl)Cl ZDHXKXAHOVTTAH-UHFFFAOYSA-N 0.000 description 1
- 239000005052 trichlorosilane Substances 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
Landscapes
- Silicon Compounds (AREA)
Abstract
Description
【発明の詳細な説明】
３、発明の詳細な説明
（産業上の利用分野）
本発明は、高純度けい素の精製方法に関し、特に半導体
級の高純度けい素を高い収率と低コストとを実現して有
利に製造する方法について提案する。[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for purifying high-purity silicon, and in particular to a method for purifying high-purity silicon of semiconductor grade with high yield and low cost. We propose a method for achieving this and manufacturing it advantageously.
（従来の技術）
現在、金属けい素の精製法としては、シーメンス法（例
えば、特公昭３５−２９８２号）と呼ばれる方法が最も
一般的である。この方法は、金属けい素を気体状のトリ
クロロシランに交換して精留することにより高純度の半
導体級のけい素を得る方法である。しかし、この方法は
、非常にコスト高となるから、いわゆる太陽電池に供す
るようなあまり高い純度は必要としないようなけい素の
製造の場合には経済的に極めて不利である。(Prior Art) Currently, the most common method for purifying silicon metal is a method called the Siemens method (for example, Japanese Patent Publication No. 35-2982). This method is a method for obtaining highly pure semiconductor-grade silicon by exchanging metallic silicon with gaseous trichlorosilane and rectifying it. However, this method is very expensive and is extremely disadvantageous economically when producing silicon that does not require very high purity, such as for use in so-called solar cells.
また、上記シーメンス法より費用のかからない方法とし
て、金属けい素を酸または酸の混合物によって精製する
方法（例えば、米国特許第２９７２５２１号明細書）が
知られている。しかしながら、この従来方法は、長時間
の処理が必要である。また、例えば金属けい素が溶融状
態で得られる場合には、太陽電池用の基板を製造しよう
とすると、精製のための凝固、粉砕の後に再度溶解しな
ければならず経済的に不利となる。Furthermore, as a less expensive method than the Siemens method, a method is known in which silicon metal is purified using an acid or a mixture of acids (for example, US Pat. No. 2,972,521). However, this conventional method requires a long processing time. Further, for example, when metallic silicon is obtained in a molten state, when attempting to manufacture a substrate for a solar cell, it must be solidified and pulverized for purification and then melted again, which is economically disadvantageous.
また、一方向凝固法（例えば、特開昭５５−２３０８３
号）は、凝固時におこる不純物の偏析を利用して精製す
る方法であるが、炭素、リン、ホウ素等の固液分配係数
の大きな不純物は除去されにくいという欠点を有する。In addition, unidirectional solidification method (for example, Japanese Patent Application Laid-Open No. 55-23083
No.) is a purification method that utilizes the segregation of impurities that occurs during solidification, but it has the drawback that impurities with large solid-liquid partition coefficients such as carbon, phosphorus, and boron are difficult to remove.
さらに、従来の真空蒸発法（例えば、特開昭５６−３２
３１９号）は、１５００〜１７００℃において、１０−
４〜１０−６気圧程度に減圧することにより不純物、特
に蒸気圧の高い不純物を気化させて除去する方法である
が、長時間の処理と１Ｏ−４〜１０−６気圧という高真
空度を必要とするために、けい素が一酸化けい素（Ｓｉ
ｎ）として多量に損失してしまい収率が低下するといっ
た不利があった。Furthermore, conventional vacuum evaporation methods (for example, JP-A-56-32
No. 319) is 10-
This method vaporizes and removes impurities, especially impurities with high vapor pressure, by reducing the pressure to about 4 to 10-6 atmospheres, but it requires long processing times and a high degree of vacuum of 10-4 to 10-6 atmospheres. In order to
As n), there was a disadvantage that a large amount was lost and the yield decreased.
加えてこれら各従来精製方法では、炭素濃度が高くかつ
その他の不純物濃度の低い金属けい素、例えば高純度シ
リカと高純度炭素を用いた還元プロセスによって製造し
たけい素等を精製するような場合に、炭素以外の不純物
はそれ程除去する必要がないため、一般的にコスト的な
面で不利となるという問題点を抱えていた。In addition, these conventional refining methods cannot be used to purify metallic silicon with a high carbon concentration and low concentration of other impurities, such as silicon produced by a reduction process using high-purity silica and high-purity carbon. However, impurities other than carbon do not need to be removed as much, so they generally have a disadvantage in terms of cost.
（発明が解決しようとする問題点）
本発明の目的は、上記各従来技術が抱える上述した問題
点を、炭素濃度が高くかつその他の不純物濃度の低い金
属けい素、例えば高純度シリカと高純度炭素を用いた還
元プロセスによって製造さた金属けい素から、不純物、
特に炭素を、低コストで収率低下を招くことなく効果的
に除去することにより、克服するところにある。(Problems to be Solved by the Invention) It is an object of the present invention to solve the above-mentioned problems of the above-mentioned conventional techniques by using metallic silicon having a high carbon concentration and a low concentration of other impurities, such as high-purity silica. Impurities,
In particular, the problem is to be overcome by effectively removing carbon at low cost and without reducing yield.
（問題点を解決するための手段）
上掲の目的は次の事項を骨子とする構成の採用によって
有利に実現される。すなわち、不純物を含む金属けい素
から、炭素を含む不純物を除去して純度の高いけい素を
得る方法において、
■ まず、不純物含有量の少ない高炭素の金属けい素を
、溶融状態下に保持したまま捕捉体に接触させることに
より、該溶融金属けい素中に炭化けい素として存在する
炭素を捕捉除去し、■ 次いで、捕捉除去後の溶融金属
けい素を、その融点を超え１８００℃の温度域および１
０−′〜１０−４気圧の範囲に保持して減圧処理するこ
とにより、残りの炭素を除去するという高純度けい素の
精製方法である。(Means for solving the problems) The above objectives can be advantageously achieved by adopting a configuration based on the following points. In other words, in the method of obtaining highly pure silicon by removing carbon-containing impurities from impurity-containing silicon metal, first, high-carbon silicon metal with a low impurity content is held in a molten state. Carbon present in the molten metal silicon as silicon carbide is captured and removed by contacting the molten metal silicon with a capture body, and the molten metal silicon after capture and removal is heated to a temperature range of 1800°C exceeding its melting point. and 1
This is a method for purifying high-purity silicon in which remaining carbon is removed by maintaining the pressure in the range of 0-' to 10-4 atmospheres and performing a reduced pressure treatment.
なお、精製前の素材である“不純物量の少ない高炭素の
金属けい素”は、高純度シリカと高純度炭素を用いた還
元プロセスによって製造したものなどを用いる。The raw material before purification, ``high-carbon metallic silicon with a small amount of impurities,'' is manufactured by a reduction process using high-purity silica and high-purity carbon.
また、最初の段階において用いる捕捉体としては、炭素
、炭化けい素、窒化けい素、シリカあるいはこれらの混
合物からなるフィルターが好適である。Furthermore, as the trap used in the first step, a filter made of carbon, silicon carbide, silicon nitride, silica, or a mixture thereof is suitable.
（作 用）
炭素のけい素融液中での飽和溶解度は、例えばけい素の
融点（約１４１０℃）において約３９ｐｐｍ （重量比
、以下の説明も同じ）であることが知られており、それ
以上の炭素は炭化けい素の形態でけい素融液中に存在す
る。そして、この炭化けい素は、該けい素融液中に、数
〜数十ミクロン程度の微粒子の形で分散しているため、
フィルタ等の捕捉体を用いることによる捕捉、例えば濾
過による除去が可能である。(Function) It is known that the saturated solubility of carbon in a silicon melt is, for example, about 39 ppm (weight ratio, the same description below) at the melting point of silicon (about 1410°C). The above carbon exists in the silicon melt in the form of silicon carbide. Since this silicon carbide is dispersed in the silicon melt in the form of fine particles of several to several tens of microns,
Capture by using a capture body such as a filter, for example removal by filtration, is possible.
一般に、溶融金属をフィルタによって濾過する手法は、
アルミニウム等の溶湯処理において採用されており、そ
のフィルタとしてはシリカあるいはアルミナ等からなる
ものが用いられる。これに対してけい素の場合は、融点
が高くまた目標とする純度が高いためにアルミナは、け
い素用捕捉体として使用することが不可能である。けい
素によく適合する捕捉体の材質としては、炭素、炭化け
い素、窒化けい素、シリカあるいはこれらの混合物であ
る。これらは、けい素の溶融温度に十分耐えるものであ
り、さらに溶融金属けい素中に飽和溶解度以上の炭素を
含む場合の捕捉に当っても、捕捉体の溶解によるけい素
融液の汚染のおそれがないばかりでなく、前述した炭化
けい素の微粒子を、吸着作用により効果的に捕捉するこ
とが可能である。この際、炭素以外の不純物の汚染を防
止するために高純度の捕捉体材質が望ましいことは言う
までもない。Generally, the method of filtering molten metal with a filter is
It is used in the treatment of molten metals such as aluminum, and its filters are made of silica, alumina, etc. In contrast, in the case of silicon, alumina cannot be used as a trap for silicon due to its high melting point and high target purity. Materials for the trapping body that are well compatible with silicon include carbon, silicon carbide, silicon nitride, silica, or mixtures thereof. These materials are sufficiently resistant to the melting temperature of silicon, and even when capturing carbon in the molten metal silicon that exceeds its saturation solubility, there is a risk of contamination of the silicon melt due to dissolution of the capture material. Not only is it completely free of silicon carbide particles, but it is also possible to effectively trap the silicon carbide particles mentioned above through adsorption. At this time, it goes without saying that a highly pure trapping material is desirable in order to prevent contamination with impurities other than carbon.
また捕捉体の形状は、炭化けい素の粒子が効果的に捕捉
されるようにするために、融液に対して表面積の大きな
もの、例えば繊維状のフィルタが最も好適である。繊維
状のものを用いた場合、繊維径は、けい素微粒子の吸着
効率から上限が決まり、また繊維自体の剥離によるけい
素融液への混入から下限がそれぞれ決定され、数〜数百
ミクロン程度のものが望まれる。もちろん、この捕捉体
の材質として、直径数ミリメートル以下の粒状のものを
用いても同じ効果が達成される。Furthermore, in order to effectively capture silicon carbide particles, the shape of the capture body is most preferably one that has a large surface area relative to the melt, such as a fibrous filter. When using fibrous materials, the upper limit of the fiber diameter is determined by the adsorption efficiency of silicon fine particles, and the lower limit is determined by the amount of silicon melt mixed into the silicon melt due to peeling of the fibers themselves, ranging from several to several hundred microns. is desired. Of course, the same effect can be achieved even if a granular material with a diameter of several millimeters or less is used as the material of the trapping body.
なお、捕捉体による炭化けい素捕捉除去の効果を促進す
るために、けい素融液の温度としては、炭素の飽和溶解
度の最も小さな、融点直上で行うことが望ましい。この
ような捕捉体による炭化けい素の捕捉除去により、けい
素融液中の炭素は飽和溶解度（例えば、融点１４１０℃
において３９ｐｐｍ ）程度まで減少させることが可能
である。In order to promote the effect of trapping and removing silicon carbide by the trapping body, it is desirable to set the temperature of the silicon melt just above the melting point, which is the lowest saturated solubility of carbon. By trapping and removing silicon carbide with such a trapping body, carbon in the silicon melt has a saturated solubility (for example, a melting point of 1410°C).
It is possible to reduce it to about 39 ppm).
上述した捕捉処理を経たけい素融液は、次に、融点から
１８００℃の温度範囲において、１０−′〜１０−４気
圧の範囲の減圧処理が施される。この処理によって溶融
金属けい素中の炭素量は５ ｐｐｍ以下に減少させるこ
とができる。すなわち、けい素融液中に溶解している炭
素は、やはりけい素融液中に溶解している酸素原子と反
応（（Ｃ）＋ （０）−Ｃ０し、−酸化炭素として除去
することができる。これらの反応において、系内を減圧
すれば、上記の反応によって生じた一酸化炭素をすみや
かに系外に除去し、−酸化炭素の分圧を低下させ反応を
促進させることができる。この時の減圧度は、排気によ
る一酸化炭素の分圧の低下度および減圧処理中の一酸化
けい素（Ｓｉｎ）としてのけい素置の損失との関係から
１０−１〜１０−４気圧が適当である。The silicon melt that has undergone the above-described trapping treatment is then subjected to a reduced pressure treatment in the range of 10-' to 10-4 atmospheres at a temperature range from the melting point to 1800°C. By this treatment, the amount of carbon in the molten silicon metal can be reduced to 5 ppm or less. That is, the carbon dissolved in the silicon melt reacts with the oxygen atoms also dissolved in the silicon melt ((C) + (0) -C0, and can be removed as -carbon oxide. In these reactions, if the pressure inside the system is reduced, the carbon monoxide generated by the above reaction can be quickly removed from the system, and the partial pressure of -carbon oxide can be lowered to accelerate the reaction. The appropriate degree of depressurization is 10-1 to 10-4 atm based on the relationship between the degree of decrease in the partial pressure of carbon monoxide due to exhaust gas and the loss of silicon monoxide (Sin) during the depressurization process. It is.
また、被処理溶融けい素の温度については、前記捕捉体
による捕捉効率、上記の反応における平衡度、さらには
減圧処理中にＳｉＯとして損失するけい素置との関係か
ら融点〜１８００℃の温度範囲にすることが必要である
。Regarding the temperature of the molten silicon to be treated, the temperature range from the melting point to 1800°C is determined based on the trapping efficiency of the trapping body, the equilibrium degree in the above reaction, and the silicon content lost as SiO during the depressurization treatment. It is necessary to do so.
上記式の反応において、酸素原子を効果的に供給し、反
応を促進するために、シリカるつぼを使用するのが望ま
しい。そして、このシリカるつぼの使用に加えあるいは
それに代わってるつぼ内に、例えばシリカ （Ｓｉｏｗ
）あるいはＳｉＯの粉末あるいは酸素もしくはこれらと
不活性ガスとの混合物を吹込んむもよい。In the reaction of the above formula, it is desirable to use a silica crucible in order to effectively supply oxygen atoms and promote the reaction. In addition to or instead of using this silica crucible, for example, silica (Siow
) Alternatively, SiO powder, oxygen, or a mixture of these and an inert gas may be blown.
本発明方法によって精製したけい素の場合、引き続いて
溶融状態のままで、太陽電池はもとより半導体原料とし
て加工することが可能である。In the case of silicon purified by the method of the present invention, it is possible to subsequently process it in a molten state as a raw material for semiconductors as well as solar cells.
（実施例）
例 １
炭素を７００ ｐｐｍ 、他の不純物を合計で１０ｐｐ
ｍ含む金属けい素１００ ｇを、１５００℃の溶融状態
に保持し、これを直径５０ミクロンの高純度炭素繊維５
０ｇを用いてろ過したところ、炭素量は５０ｐｐｍまで
減少した。引き続いて、この溶融金属けい素を高純度シ
リカるつぼ内において、３０分間の減圧処理した。第１
図は、種々の減圧度に対する最終炭素濃度および減圧処
理によって損失したけい素置について示したものである
。この図から明らかなように、１０川気圧以下の減圧処
理により炭素量は５ ｐｐｍ以下になるが、１０−４気
圧より高真空になると損失するけい素置は急激に増加す
ること力＜ＴＪ１！かめられた。(Example) Example 1 Carbon: 700 ppm, other impurities: 10 ppm in total
100 g of silicon metal containing m is held in a molten state at 1500°C, and this is made into high-purity carbon fibers with a diameter of 50 microns.
When filtered using 0 g, the carbon content was reduced to 50 ppm. Subsequently, this molten silicon metal was placed in a high purity silica crucible and subjected to a vacuum treatment for 30 minutes. 1st
The figure shows the final carbon concentration and silicon content lost due to the vacuum treatment for various degrees of vacuum. As is clear from this figure, the amount of carbon is reduced to 5 ppm or less by reducing the pressure below 10 atm, but when the vacuum is higher than 10-4 atm, the amount of silicon lost increases rapidly. I was bitten.
貫り一影
実施例１と同一の原料を用い、溶融けい素の融液温度を
融点から１９００℃まで変化させ（減圧処理における減
圧度は１０４気圧）だ場合における溶融けい素中の、最
終炭素濃度および減圧処理によって損失したけい素置に
対する影響を、第２図に示した。この図から明らかなよ
うに、溶融けい素の融液温度が１８００℃以下の場合は
良好な脱炭効果を示すが、１８００℃を超えると最終の
炭素濃度が急激に増大する。これは融液温度が上昇する
と、けい素融液中の炭素の飽和溶解度が上昇するため、
フィルタによる炭化けい素粒子の捕捉効果が減少するた
めであると考えられた。また、減圧処理中に損失するけ
い素の量も１８００℃を超えると急激に上昇することが
確められた。The final carbon in the molten silicon when the same raw materials as in Example 1 are used and the melt temperature of the molten silicon is varied from the melting point to 1900°C (the degree of vacuum in the vacuum treatment is 104 atm). The effect on the silicon content lost due to concentration and vacuum treatment is shown in FIG. As is clear from this figure, when the melt temperature of molten silicon is 1800°C or lower, a good decarburization effect is exhibited, but when it exceeds 1800°C, the final carbon concentration increases rapidly. This is because as the melt temperature increases, the saturated solubility of carbon in the silicon melt increases.
This was thought to be due to a decrease in the effectiveness of the filter in capturing silicon carbide particles. Furthermore, it was confirmed that the amount of silicon lost during the depressurization process also increases rapidly when the temperature exceeds 1800°C.
（比較例）
例 １
実施例と同一の原料（炭素７００ ｐｐｍ 、他の不純
物の合計１０ｐｐｍ ）１００ｇを、シリカるつぼ内で
１５００℃、１０−２気圧の減圧処理を３０分間施した
ところ、炭素濃度は５００ ｐｐｅａまでしか減少しな
かった。(Comparative Example) Example 1 When 100 g of the same raw material as in Example (carbon 700 ppm, total of other impurities 10 ppm) was subjected to a vacuum treatment at 1500°C and 10-2 atm for 30 minutes in a silica crucible, the carbon concentration decreased to only 500 ppea.
■−１
上記比較例１に続いて２０時間の減圧処理を施したとこ
ろ、炭素濃度は４ ｐｐｍまで除去することができたが
、溶融けい素の量は５５ｇとなり、４５％も減少した。(1)-1 Following Comparative Example 1 above, a vacuum treatment was performed for 20 hours, and the carbon concentration was able to be removed to 4 ppm, but the amount of molten silicon was 55 g, a decrease of 45%.
（発明の効果）
以上説明したように本発明によれば、溶融状態の金属け
い素中の炭素を溶融状態のままで除去することが可能で
あるから、凝固や粉砕の費用がかからず低コストのけい
素精製法を提供することができる。本発明は、捕捉体に
よる炭化けい素の捕捉処理と、それに続く減圧処理とを
組合わせることにより減圧処理単独で精製する場合と比
べて、けい素の一酸化けい素としての損失を極端に低下
させることができ、けい素の収率が大幅に上昇する。(Effects of the Invention) As explained above, according to the present invention, it is possible to remove carbon from molten metal silicon while it is in the molten state. A cost effective silicon purification method can be provided. The present invention combines the capture treatment of silicon carbide with a capture body and the subsequent depressurization treatment, thereby dramatically reducing the loss of silicon as silicon monoxide compared to the case of refining with the depressurization treatment alone. The yield of silicon can be greatly increased.
また、本発明は、原料が溶融状態で得られると共に炭素
濃度が高くかつ他の不純物濃度が低いけい素を精製する
ような場合に特に有用である。Further, the present invention is particularly useful when the raw material is obtained in a molten state and is used to purify silicon having a high carbon concentration and a low concentration of other impurities.
【図面の簡単な説明】
第１図は、種々の減圧度に対する溶融けい素中の最終炭
素濃度および減圧処理により損失するけい素置への影響
を示すグラフ、
第２図は、溶融けい素の融液温度に対する最終炭素温度
および減圧処理により損失するけい素置への影響を示す
グラフである。
特許出願人 川崎製鉄株式会社
代理人弁理士 杉 村 暁 秀同 弁理士
杉 村 興 作第１図
先す逼圧）
第２図[Brief explanation of the drawings] Figure 1 is a graph showing the final carbon concentration in molten silicon and the effect on the silicon content lost due to depressurization treatment for various degrees of depressurization. 2 is a graph showing the influence of melt temperature on final carbon temperature and silicon content lost due to depressurization treatment. Patent applicant Kawasaki Steel Co., Ltd. Representative Patent Attorney Hideto Sugimura Akira Sugimura Patent Attorney Oki Sugimura (Figure 1) Figure 2
Claims (1)
除去して純度の高いけい素を得る方法において、 まず、不純物含有量の少ない高炭素の金属 けい素を、溶融状態下に保持したまま捕捉体に接触させ
ることにより、該溶融金属けい素中に炭化けい素として
存在する炭素を捕捉除去し、次いで、捕捉除去後の溶融
金属けい 素を、その融点を超え１８００℃の温度域および１０＾
−＾１〜１０＾−＾４気圧の範囲に保持して減圧処理す
ることにより、残りの炭素を除去することを特徴とする
高純度けい素の精製方法。[Claims] 1. In a method for obtaining highly pure silicon by removing carbon-containing impurities from metallic silicon containing impurities, first, high-carbon metallic silicon with a low impurity content is melted. Carbon existing in the form of silicon carbide in the molten metal silicon is captured and removed by bringing it into contact with a capture body while being maintained under the same conditions, and then the molten metal silicon after capture and removal is heated to a temperature exceeding its melting point of 1800 Temperature range of °C and 10^
A method for purifying high-purity silicon, which comprises removing remaining carbon by maintaining the pressure in the range of -^1 to 10^-^4 atmospheres and performing a reduced pressure treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13287486A JPS62292613A (en) | 1986-06-10 | 1986-06-10 | Method for purifying high purity silicon |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13287486A JPS62292613A (en) | 1986-06-10 | 1986-06-10 | Method for purifying high purity silicon |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62292613A true JPS62292613A (en) | 1987-12-19 |
| JPH0417890B2 JPH0417890B2 (en) | 1992-03-26 |
Family
ID=15091573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13287486A Granted JPS62292613A (en) | 1986-06-10 | 1986-06-10 | Method for purifying high purity silicon |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62292613A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5182091A (en) * | 1990-05-30 | 1993-01-26 | Kawasaki Steel Corporation | Method and apparatus for purifying silicon |
| JP2006240914A (en) * | 2005-03-02 | 2006-09-14 | Nippon Steel Corp | Method for removing carbon from silicon |
| JP2007302513A (en) * | 2006-05-11 | 2007-11-22 | Sharp Corp | Method for separating silicon carbide and silicon and apparatus used for the method |
| WO2009001547A1 (en) * | 2007-06-26 | 2008-12-31 | Panasonic Corporation | Method for purifying silicon metal and method for producing silicon ingot |
| CN109052407A (en) * | 2018-08-22 | 2018-12-21 | 昆明理工大学 | A kind of recycling and method of purification of silicon cutting waste material |
-
1986
- 1986-06-10 JP JP13287486A patent/JPS62292613A/en active Granted
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5182091A (en) * | 1990-05-30 | 1993-01-26 | Kawasaki Steel Corporation | Method and apparatus for purifying silicon |
| JP2006240914A (en) * | 2005-03-02 | 2006-09-14 | Nippon Steel Corp | Method for removing carbon from silicon |
| JP2007302513A (en) * | 2006-05-11 | 2007-11-22 | Sharp Corp | Method for separating silicon carbide and silicon and apparatus used for the method |
| WO2009001547A1 (en) * | 2007-06-26 | 2008-12-31 | Panasonic Corporation | Method for purifying silicon metal and method for producing silicon ingot |
| US8668895B2 (en) | 2007-06-26 | 2014-03-11 | Panasonic Corporation | Purifying method for metallic silicon and manufacturing method of silicon ingot |
| CN109052407A (en) * | 2018-08-22 | 2018-12-21 | 昆明理工大学 | A kind of recycling and method of purification of silicon cutting waste material |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0417890B2 (en) | 1992-03-26 |
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