200909349 九、發明說明 【發明所屬之技術領域】 本發明有關作爲製造晶態矽太陽能電池之原材料的太 陽能等級矽（Si)的製造。該Si金屬係藉由直接還原 SiCl4而獲得，SiCl4係常見之高純度等級前驅體。 【先前技術】 適用於太陽能電池應用的矽通常係根據西門子法或其 變體熱解SiHCl3而製造。該方法產出非常高純度之矽， 但其緩慢、高度耗能而且需要大額投資。 形成供太陽能電池用之S i的替代途徑係以諸如Zn之 金屬還原S i C14。由於此方法的投資成本較低且耗能降低 ，故其具有大幅降低成本的潛力。Zn在氣相中直接還原 SiCl4 係描述於 US 2,773,745、US 2,8 04,3 77 > US 2,909,411或US 3,04 1,145。當使用Zn蒸氣時，在流體化 床型反應器形成顆粒狀矽產物，使得Si分離更加容易。 不過，以此原理爲基礎之工業方法技術上相當複雜。 以液態Zn直接還原SiCl4係描述於JP 1 1 -092 1 3 0與 JP 1 1 -0 1 1 925。Si係形成細粉末狀，並藉氣態ZnCl2將其 帶走而將該Si與液態Zn分離。不過，並未解釋何以發生 ZnCl2帶走細粉末狀Si的原因。已證實不可能重複此等專 利中所述之方法。可令大量所產生之多晶矽粉末與該氯化 鋅蒸氣一起排出的基本技術特性消失。 一般而言，並不特別需要將該矽製成細粉末。此種粉 -5- 200909349 末確實相當容易氧化’特別是在該顆粒表面。此氧化作用 使得隨後相當難將該矽再熔融成多晶或單晶塊。可能需要 粒化/壓實步驟，此令該方法變複雜。 在W02006/1001 1 4 A1中揭示一種以液態Zn直接還 原SiCl4之方法，其中該令SiCl4與Zn接觸之步驟以及所 得之Si與ZnCl2分離之步驟係在同一反應器中進行。不過 ，由於流率過低之故已證實該方法不具經濟效益’該流率 等同於該SiCl 4之莫耳供應率。此外，已確定令流率提高 至本文件所揭示之數字（例如，實施例1中之0.023莫耳 %/莫耳.分鐘）以上，則夾帶之Si損失變得無法接受。 在W02007/01 3644 A1中，在流率爲低於1.0莫耳％/ 莫耳.分鐘金屬下，將氯矽烷進料至該金屬熔體中，較佳 係鋁。該方法並未進一步探查介於SiCl4與液態Zn之間的 反應，因此未提出最佳化。在根據此方法之實施例中，與 A1反應之產率係1 7 . 1 %或更低，該產率係將所收集之S i (金屬Si)除以Si進料（作爲SiCl4)而計算求得。此意 指（至少）82.9%進料至該反應器之Si因夾帶而損失，或 者未反應。很清楚看出使用A1作爲還原劑之系統高度地 不經濟。再者，鋁無礙地是HP矽中不受歡迎的雜質，此 一事實令整體製程曝於風險之下。 【發明內容】 本發明目的係對先前技術中之問題提供解決之道。爲 此’根據本發明，藉由用以將SiCl4轉換成Si金屬之方法 200909349 以經濟方式獲得高純度Si金屬，該方法包含步驟： - 於一反應器中提供初始量之熔融Zn浴； - 將氣態SiCl4吹進該熔融浴zn，因而獲得含Si 之金屬相與氯化Zn; - 分離氯化Zn與含Si之金屬相；以及 - 在高於Zn沸點之溫度下純化含Si之金屬相，因 而汽化Ζ η並獲得S i金屬； 其中’接觸與分離步驟係於單一反應器中進行，該方 法特徵係接觸步驟係以莫耳流速介於0.1與0.8莫耳％ /莫 耳·分鐘’較佳係介於0.4與0.8莫耳％ /莫耳.分鐘之初始 Zn量射入SiCU，最大區域供應速率爲50 kg/分鐘/m2浴 表面。 該接觸與分離步驟係在單一反應器中進行。藉由大部 分（多於5〇重量％ )所形成之Si係維持液態金屬相而可 能達到此一目的。 除了是爲溶質之Si以外，該接觸步驟中獲得之含有 Si之金屬相亦包含至少某些呈固態之Si。當Zn金屬在Si 中達到飽和時’確實亦會形成固態Si爲懸浮粒子，但亦 會獲得漂浮在剩餘Zn浴表面之Si-Zn浮渣。藉由令SiCl4 之莫耳供應率提高到高於0.1莫耳％/莫耳·分鐘該初始Zn 含量，該S i -Zn浮渣層係快速形成’並且藉由蒸發氯化Zn 之夾帶作用而適當限制微粒S i流失。就經濟原因來說， 該莫耳供應率較佳係多於或等於〇_4莫耳％/莫耳.分鐘。該 0_8莫耳％/莫耳·分鐘之上限確保浮渣層不會受到因上升氣 200909349 體而帶走過多固態Si之程度的干擾。 浮渣有助於達到更高流率，同時亦避 並減少小液滴被逐步形成的氣體帶走 該Zn浴的最大區域供應速率應pj 浴表面，使能對大量SiC 14吹氣且不 在此等限制內進行該方法，可獲得處 而隨著蒸發氯化Zn而夾帶的Si流失 重量％)。區域供應速率建議超過10 kg/分鐘/m2浴表面以便以經濟方式進 使在高射出速率下亦可獲得SiCl4轉{ 。該實例中，該裝配的生產力與射出 ，就既定S i之製造方法而言，流率 很清楚看出至少300cm2浴表面，較句 面適於與前文提及之工作條件倂用。 較佳地，藉由使用多重沉水噴嘴 地分散在該浴，該沉水噴嘴設有孔狀 器或任何其他適用工具或工具之組合 體氣體（諸如N2)射出。 藉由在高於氯化Zn (其會蒸發 作該接觸步驟以結合該接觸與該分離 許該氯化Zn逸散並加以收集以供進-於純化步驟期間將該溫度提高到 且特別是在減壓或在真空下操作該方 作用較佳係再次在與前兩個處理步驟 該浴表面存有Si-Zn 免該液體浴飛濺過高 〇 I制爲50 kg /分鐘/ m2 造成過多噴濺。藉由 理經濟的最佳化，因 係受限在低於1 5 % ( ，更佳爲1 2或更高 行該方法。確實，即 匕成Si之高轉化產率 流率直接關連。因此 愈高則投資愈低。也 巨係至少500(^2浴表 將該氣態SiCl4充分 插塞、旋轉氣體噴射 。該SiCl4可隨著載 )之沸點的溫度下操 步驟是有利的。可准 -步加工。 高於S i之熔點，並 法是有利的。該純化 中相同之反應器中進 -8- 200909349 行。 亦有利的是再循環不被視爲最終產物之不同物流其中 之一或更多者： - 對所獲得之氯化Zn進行熔融鹽電解，因而回收 Zn與氯，該Zri可再循環至SiCl4還原步驟，該氯可再循 環至Si氯化處理以製造SiCl4; - 將於純化步驟中汽化之Zn可加以冷凝並再循環 至該s i C 14轉化處理；及/或 - 離開該接觸步驟之未反應SiCl4流分可加以再循 環至該S i C 14轉化處理，例如於冷凝之後。 根據本發明，以液態Zn還原SiCl4。因此本方法之技 術遠比氣態還原處理所需要的技術簡單直接。可獲得已溶 解與固態Si二者之含Si合金，同時形成蒸氣形式之氯化 Zn爲佳。可自Zn之氯化物收回Zn，例如藉由熔融鹽電解 進行’並重複用於SiCl4還原。可在高溫一高於Zn與氯化 Zn二者沸點但低於Si本身之沸點（23 5 5艺）之溫度—加 以純化該含有Si合金。可以加以收回該蒸發的Zn並再用 於SiCl4還原。亦可在本步驟中將任何其他揮發性元素加 以去除。因此，可能關閉Zn上的迴路，因而避免雜質經 由新添加作用而導入該系統。 在本發明較佳具體實例中，令氣態S i C14與液態Ζ η在 大氣壓力並在高於ZnCl2之沸點（ 732 °C)並低於Zn之沸 點（9 0 7 °C )之溫度下接觸。該較佳操作溫度係7 5 〇至8 8 〇 °C ’此係能確保充分高反應動力同時限制金屬Zn蒸發的 -9- 200909349 範圍。 在代表性具體實例中，將該熔融Zn置於一反應器， 該反應器較佳係由石英或其他高純度材料（諸如石墨）所 製成。經由沉水管將該於室溫下呈液態之SiCl4注入該鋅 。該注射係在含Zn之容器的下半部分進行。於該管中受 熱的Sicu實際係以氣體形式注射。或者，該siC丨4可在 另一裝置中被汽化，並將該蒸氣進料至該注射管。該注射 管末端可配有分散裝置，諸如孔狀插塞或經燒結玻璃。真 正重要的是該Sici4與Zn間具有良好接觸以便獲得高還原 產率。若並非此情況，則可能發生部分還原成SiCl2，或 者SiCl4未反應即離開鋅。藉由適當之SiCl4-Zn接觸，觀 察到接近1 〇 0 %之轉化率。 還原法產生ZnCl2。其沸點爲732 °C，並且在較佳操 作溫度下爲氣態。其經由頂部離開該含Zn之容器。在一 獨立坩堝中加以冷凝並收集該蒸氣。 該方法亦產生Si。該Si溶解於熔融Zn至多達其溶解 度限制。該S i於ζ η中之溶解度隨著溫度而提高，並於 907°C中受限至約4%，907°C爲純Zn的大氣壓沸點。 在另一較有利本發明具體實例中，容許該含Si合金 冷卻至略高於Zn熔點之溫度，例如6 0 0 °C。該最初溶解 的Si大部分於冷凝時結晶，並與已存在該浴中之上層固 態流分的固態Si —起累積。該金屬相之下層液態流分已 耗盡S i，並且可藉由例如適當方法，例如藉由傾倒加以分 離。此金屬可直接再用於另外的SiCl4還原。然後對該上 -10- 200909349 層富含S i流分進行上述純化，其優點係可以相當大幅減 少待蒸發之Zn量。 當所有剩餘鋅已經蒸發而且矽係呈熔融狀態時，可在 單一步驟中令該溶融矽固化，該步驟係選自諸如丘克拉斯 基（Czochralski )法、定向固化與帶式生長等拉晶法。該 帶式生長法包括其變體，諸如基材上之帶式生長（RGS ) ，其直接產生R G S S i晶圓。 或者，可將該熔融矽加以粒化，令該顆粒進料至一熔 爐’較佳係以連續方式進料，因此在單一步驟中將該熔融 矽加以固化，該步驟係選自諸如定向固化與帶式生長等拉 晶法。然後根據所使用之固化法將所得之固態材料直接或 於切片之後進一步加工成太陽能電池 可藉由汽化作用將該Zn與典型微量雜質（諸如T1、 Cd與Pb)與該含Si合金加以分離。然後獲得純度爲5N 至6N之Si。使用Cl2及/或氣態氯化Si之特別高溫鼓泡 或起泡步驟通常形成具有更優良純度之Si。爲了進行此操 作，將該溫度提高至高於S i之熔點（1 4 1 4 °C )但低於沸 點（23 5 5 °C )。以此處理步驟可以有效率消除的某些元素 係Cr·、Cu、Μη、Al ' Ca、B與P。因此較佳具體實例係 由藉加熱至高於Si之熔點並將Cl2及/或氣態氯化Si化合 物注入含有Si之金屬相而令Zn汽化，消除雜質並獲得Si 金屬純化該含有Si之金屬相所組成，因此該接觸與分離 步驟係在單一反應器中進行。 本發明另一優點係可在該純化處理結束時收集呈熔融 -11 - 200909349 狀態之Si。在先前技術西門子法與其變體中實際上係製得 固態S i，必須藉慣用技術（拉晶或定向固化）將之再熔融 以成形爲晶圓。直接製得呈熔融狀態之Si使得原料製造 與晶圓製造之步驟整合性更佳，進一步降低該方法之總耗 能以及晶圓製造之成本。該液態Si確實質可直接進料至 鑄塊機或拉晶機中。亦可能在帶式生長裝備中處理該Si。 若不希望製造即可用晶圓材料而僅希望製造中間固態 原料，粒化該經純化Si顯得較爲有利。所得之顆粒比例 如西門子法爲基礎之方法中所得者更容易處理。在帶式生 長技術中此點特別重要。製造自由流動顆粒使得可以連續 進料CZ爐或帶式生長裝備。 【實施方式】 實施例1 於放置在感應爐中之石墨反應器中將700kg之金屬 Zn加熱至850°C。該浴之高度約50cm，直徑爲50cm。使 用蠕動栗將SiCl4(沸點58°C)送至蒸發器（夾層加熱容 器）。然後令該氣態SiCl4經由石英管起泡通過該Zn浴。 該SiCl4流經計算爲150kg/小時，而且總添加量爲45 0kg 。該流率相當於12.7kg/分鐘/m2浴表面。不同之處係所供 應之SiCl4量爲0.137莫耳％/莫耳.分鐘該Zn莫耳之初始 數。觀察到，當以Si令浴飽和之後，於該浴表面迅速形 成Si-Zn浮渣層。於此反應期間所形成的ZnCl2係蒸發並 冷凝於連接至該反應器之碳化矽管中，而且加以收集在一 -12- 200909349 獨立容器中。將任何未反應SiCl4收集在連 容器的濕洗器中。獲得Zn-Si相，其Si含量 此相逐漸加熱以便蒸發該Zn，將該Zn冷凝 中。令溫度提高至1450°C並於此水準維持1 熔融之矽澆鑄入一石英容器並使之固化至 66kg之金屬矽。因此該Si反應產率約8 8% 歸咎於隨著冗!1(：12蒸氣逸散而夾帶Si粒子D 全轉化成Si金屬。該剩餘Si中有約6kg係 現，約3kg係在洗滌器中發現。所得之矽1 之 B、0.0 5 p p m 之 P、0 · 2 ppm 之 A1 與 〇·3 雜質。Zn低於50ppb。 接至該ZnCl2 [約 1 6.7 %。將 於一獨立容器 小時。然後將 室溫。收集得 。該Si損失可 L及SiCl4未完 於ZnCl2中發 爹有低於 5ppb P P m之總金屬 -13-BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of solar energy grade cerium (Si) as a raw material for producing a crystalline germanium solar cell. The Si metal is obtained by direct reduction of SiCl4, a common high purity grade precursor of the SiCl4 system. [Prior Art] The ruthenium suitable for solar cell applications is usually produced by pyrolysis of SiHCl3 according to the Siemens method or its variant. This method produces very high purity enthalpy, but it is slow, highly energy intensive and requires large investments. An alternative way to form S i for solar cells is to reduce S i C14 with a metal such as Zn. Because of its low investment cost and reduced energy consumption, this method has the potential to significantly reduce costs. Direct reduction of Zn in the gas phase SiCl4 is described in US 2,773,745, US 2,8 04,3 77 > US 2,909,411 or US 3,04 1,145. When Zn vapor is used, a granular ruthenium product is formed in the fluidized bed type reactor, making Si separation easier. However, industrial methods based on this principle are technically quite complex. Direct reduction of SiCl4 by liquid Zn is described in JP 1 1 -092 1 3 0 and JP 1 1 -0 1 1 925. The Si system is formed into a fine powder and is taken away by gaseous ZnCl2 to separate the Si from the liquid Zn. However, it does not explain why ZnCl2 takes away fine powdered Si. It has proven impossible to repeat the methods described in these patents. The basic technical characteristics of discharging a large amount of the produced polycrystalline silicon powder together with the zinc chloride vapor disappear. In general, it is not particularly necessary to make the crucible into a fine powder. This powder -5 - 200909349 is quite easy to oxidize at the end 'especially on the surface of the granules. This oxidation makes it relatively difficult to re-melt the crucible into a polycrystalline or single crystal block. The granulation/compaction step may be required, which complicates the process. A method for directly reducing SiCl4 in liquid Zn is disclosed in WO2006/1001 1 4 A1, wherein the step of contacting SiCl4 with Zn and the step of separating Si and ZnCl2 are carried out in the same reactor. However, this method has proven to be uneconomical due to the low flow rate. This flow rate is equivalent to the molar supply rate of the SiCl 4 . Further, it has been determined that the flow rate is increased to the number disclosed in the present document (for example, 0.023 mol%/mole.min in Example 1), and the entrapped Si loss becomes unacceptable. In WO2007/01 3644 A1, chlorodecane is fed to the metal melt at a flow rate of less than 1.0 mol% per mole of minute metal, preferably aluminum. This method did not further explore the reaction between SiCl4 and liquid Zn, and thus no optimization was proposed. In the examples according to this method, the yield of reaction with A1 is 17.1% or less, which is calculated by dividing the collected S i (metal Si) by the Si feed (as SiCl4). Seek. This means that (at least) 82.9% of the Si fed to the reactor is lost due to entrainment or is unreacted. It is clear that systems using A1 as a reducing agent are highly uneconomical. Furthermore, aluminum is an unwelcome impurity in HP, and this fact exposes the overall process to risk. SUMMARY OF THE INVENTION The object of the present invention is to provide a solution to the problems in the prior art. To this end, according to the invention, a high-purity Si metal is obtained economically by a method for converting SiCl4 to Si metal, 200909349, the method comprising the steps of: - providing an initial amount of molten Zn bath in a reactor; Gaseous SiCl4 is blown into the molten bath zn, thereby obtaining a metal phase containing Si and Zn chloride; - separating the metal phase of Zn and Si; and - purifying the metal phase containing Si at a temperature higher than the boiling point of Zn, Thus vaporization Ζ η and obtaining the Si metal; wherein the 'contact and separation steps are carried out in a single reactor, the method is characterized by a contact step with a molar flow rate of between 0.1 and 0.8 mol% / mol·min' The optimum amount of Zn is between 0.4 and 0.8 mol% per mole. The initial Zn amount is injected into the SiCU with a maximum area supply rate of 50 kg/min/m2 bath surface. This contacting and separating step is carried out in a single reactor. It is possible to achieve this by maintaining a liquid metal phase by a Si portion formed by a majority (more than 5% by weight). In addition to being a solute Si, the metal phase containing Si obtained in the contacting step also contains at least some solid Si. When the Zn metal is saturated in Si, it is true that solid Si is also formed as suspended particles, but Si-Zn scum floating on the surface of the remaining Zn bath is also obtained. By increasing the molar supply rate of SiCl4 to above the initial Zn content of 0.1 mol%/m·min, the Si-Zn scum layer rapidly forms and is entrained by evaporating Zn chloride. Appropriately limit the loss of particles S i . For economic reasons, the molar supply rate is preferably more than or equal to 〇_4 mol%/mole.min. The upper limit of 0_8 mol%/mole·minute ensures that the scum layer is not disturbed by the degree of excess solid Si taken away by the rising gas 200909349. The scum helps to achieve a higher flow rate, while also avoiding and reducing the droplets being gradually formed by the gas. The maximum area supply rate of the Zn bath should be pj the bath surface, enabling a large amount of SiC 14 to be blown and not The method is carried out within the limits, and the weight loss of Si entrained by evaporation of Zn chloride is obtained. The regional supply rate is recommended to exceed 10 kg/min/m2 bath surface in order to economically achieve SiCl4 transfer at high injection rates. In this example, the productivity and ejection of the assembly, in terms of the manufacturing method of the given S i , the flow rate clearly shows at least 300 cm 2 of the bath surface, which is more suitable for use with the working conditions mentioned above. Preferably, the submerged nozzle is provided with a combination of a blister or any other suitable tool or tool (e.g., N2) to be dispersed in the bath. Increasing the temperature to and during the purification step by higher than Zn chloride (which will evaporate as the contacting step to combine the contact with the separation and the chlorinated Zn is dispersed and collected for feeding) It is preferred to operate the pressure under reduced pressure or under vacuum. The Si-Zn is again present on the surface of the bath with the first two treatment steps. The liquid bath is splashed too high and the temperature is 50 kg / min / m2 to cause excessive splashing. By optimizing the economy, the method is limited to less than 15% (and more preferably 12 or higher). Indeed, the high conversion yield rate of Si is directly related. The higher the investment, the lower the investment. It is also advantageous to operate at a temperature of at least 500 (^2 bath table to fully insert the gaseous SiCl4, rotating gas jet. The SiCl4 can follow the boiling point of the carrier). Step processing. Above the melting point of S i , and the method is advantageous. The same reactor in the purification is carried out in the range of -8-200909349. It is also advantageous to recycle one of the different streams which are not regarded as the final product or More: - Molten salt electrolysis of the obtained Zn chloride, thus recovering Zn Chlorine, the Zri may be recycled to the SiCl4 reduction step, the chlorine may be recycled to the Si chlorination treatment to produce SiCl4; - the Zn vaporized in the purification step may be condensed and recycled to the si C 14 conversion treatment; / or - the unreacted SiCl4 fraction leaving the contacting step can be recycled to the S i C 14 conversion treatment, for example after condensation. According to the invention, SiCl4 is reduced with liquid Zn. Thus the technique of the process is far more than gaseous reduction The technology required for the treatment is simple and straightforward. It is preferable to obtain a Si-containing alloy which has been dissolved and solid Si, and it is preferable to form Zn chloride in a vapor form. The Zn can be recovered from the Zn chloride, for example, by molten salt electrolysis. And repeated for SiCl4 reduction. The Si-containing alloy can be purified at a high temperature higher than the boiling point of both Zn and Zn, but lower than the boiling point of Si itself (25 5 5 art). The evaporation can be recovered. Zn is reused for SiCl4 reduction. Any other volatile elements can also be removed in this step. Therefore, it is possible to turn off the loop on the Zn, thus avoiding the introduction of impurities into the system via a new addition. In a preferred embodiment of the invention, gaseous S i C14 is contacted with liquid Ζ at atmospheric pressure and at a temperature above the boiling point of ZnCl 2 ( 732 ° C) and below the boiling point of Zn (9 7 7 ° C). The preferred operating temperature is from 7 5 8 to 8 8 〇 ° C ' This system ensures a sufficiently high reaction power while limiting the range of -9-200909349 for metal Zn evaporation. In a representative embodiment, the molten Zn is placed in a The reactor, which is preferably made of quartz or other high purity material such as graphite. The SiCl4 which is liquid at room temperature is injected into the zinc via a submerged water pipe. The injection is carried out in the lower half of the container containing Zn. The Sicu heated in the tube is actually injected as a gas. Alternatively, the siC丨4 can be vaporized in another device and the vapor is fed to the syringe. The end of the syringe can be provided with a dispersing device such as a hole plug or sintered glass. It is really important that the Sici4 has good contact with Zn in order to obtain a high reduction yield. If this is not the case, partial reduction to SiCl2 may occur, or SiCl4 may leave the zinc without reacting. A conversion of approximately 1 〇 0 % was observed by appropriate SiCl4-Zn contact. The reduction method produces ZnCl2. It has a boiling point of 732 ° C and is gaseous at the preferred operating temperature. It leaves the Zn containing vessel via the top. Condensate in a separate crucible and collect the vapor. This method also produces Si. The Si dissolves in the molten Zn up to its solubility limit. The solubility of this S i in η η increases with temperature and is limited to about 4% at 907 ° C, which is the atmospheric boiling point of pure Zn. In another preferred embodiment of the invention, the Si-containing alloy is allowed to cool to a temperature slightly above the melting point of Zn, for example, 600 °C. Most of the initially dissolved Si crystallizes upon condensation and accumulates with solid Si which already exists in the upper solids fraction of the bath. The liquid fraction below the metal phase has been depleted of S i and can be separated by, for example, a suitable method, for example by pouring. This metal can be reused directly for additional SiCl4 reduction. This purification of the upper -10 200909349 layer of the Si-rich fraction is then carried out with the advantage that the amount of Zn to be evaporated can be considerably reduced. When all of the remaining zinc has evaporated and the lanthanide is in a molten state, the molten lanthanum can be solidified in a single step, which is selected from a crystal pulling method such as Czochralski method, directional solidification and belt growth. . The ribbon growth process includes variations thereof, such as ribbon growth (RGS) on a substrate, which directly produces the R G S S i wafer. Alternatively, the molten crucible may be granulated such that the pellet is fed to a furnace 'preferably fed in a continuous manner, thus curing the molten crucible in a single step selected from, for example, directional solidification and Pulling method such as belt growth. The resulting solid material can then be further processed into solar cells, either directly or after slicing, depending on the curing method used. The Zn can be separated from the Si-containing alloy by vaporization with typical trace impurities such as T1, Cd and Pb. Then, Si having a purity of 5N to 6N is obtained. A particularly high temperature bubbling or foaming step using Cl2 and/or gaseous chlorinated Si typically forms Si with better purity. To do this, the temperature is raised above the melting point of Si (1 4 1 4 °C) but below the boiling point (23 5 5 °C). Some of the elements that can be effectively eliminated by this processing step are Cr·, Cu, Μη, Al ' Ca, B, and P. Therefore, a preferred embodiment is to purify the Zn by heating to a melting point higher than Si and injecting a Cl2 and/or gaseous chlorinated Si compound into the metal phase containing Si to remove impurities and obtain Si metal. Composition, so the contacting and separating steps are carried out in a single reactor. Another advantage of the present invention is that Si can be collected in the molten state of -11 - 200909349 at the end of the purification treatment. In the prior art Siemens process and its variants, the solid state S i was actually produced, which must be remelted by conventional techniques (drawing or directional solidification) to form into a wafer. The direct formation of Si in a molten state allows for better integration of the steps of raw material fabrication and wafer fabrication, further reducing the overall energy consumption of the process and the cost of wafer fabrication. The liquid Si can be fed directly into the ingot or crystal puller. It is also possible to process the Si in belt growth equipment. If it is not desired to manufacture wafer materials and only intermediate solid materials are desired, it is advantageous to granulate the purified Si. The resulting proportion of particles is easier to handle in a method based on the Siemens method. This is especially important in belt growth technology. The manufacture of free flowing granules allows continuous feeding of CZ furnaces or belt growth equipment. [Embodiment] Example 1 700 kg of metal Zn was heated to 850 ° C in a graphite reactor placed in an induction furnace. The bath has a height of about 50 cm and a diameter of 50 cm. SiCr4 (boiling point 58 ° C) was sent to the evaporator (interlayer heating vessel) using a creeping pump. The gaseous SiCl4 is then bubbled through the Zn bath via a quartz tube. The SiCl4 flow was calculated to be 150 kg/hr, and the total addition amount was 45 0 kg. This flow rate corresponds to a bath surface of 12.7 kg/min/m2. The difference is that the amount of SiCl4 supplied is 0.137 mol%/mole.min. The initial number of Zn moles. It was observed that after saturating with a Si bath, a Si-Zn scum layer was rapidly formed on the surface of the bath. The ZnCl2 formed during this reaction was evaporated and condensed in a tantalum carbide tube connected to the reactor, and collected in a separate container of -12-200909349. Any unreacted SiCl4 was collected in a wet scrubber of the connected vessel. A Zn-Si phase is obtained, the Si content of which is gradually heated to evaporate the Zn, and the Zn is condensed. The temperature was raised to 1,450 ° C and maintained at this level and melted into a quartz vessel and solidified to 66 kg of metal crucible. Therefore, the Si reaction yield is about 8 8%. This is attributed to the complete conversion of the entrained Si particles D into Si metal with the redundancy of 1 (:12 vapour escaping. About 6 kg of the remaining Si is present, and about 3 kg is in the scrubber. It was found that the obtained 矽1 B, 0.0 5 ppm P, 0 · 2 ppm of A1 and 〇·3 impurities. Zn is less than 50 ppb. Connected to the ZnCl 2 [about 16.7%. will be in a separate container for hours. Then, it is collected at room temperature. The Si loss can be L and the total metal-13- of SiCl4 is not completed in ZnCl2 and has less than 5 ppb PP m.