201247949 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種多晶晶圓（wafer )及其製造方 法、以及多晶材料的鑄造方法’本發明尤其是有關於可獲 得強度高的多晶鑄錠（ingot)的多晶材料的鑄造方法、以 及如下的多晶晶圓，該多晶晶圓是對多晶塊體（block)進 行切割（slice)而製造，且單元（cell)製程或模組（m〇dule) 製程中的劃痕少，上述多晶塊體是將上述多晶鑄錠予以切 斷而成。 【先前技術】 目前，主要使用矽（silicon)結晶作為太陽電池的製 造用的基板。 矽結晶有單晶與多晶，使用單晶矽作為基板的太陽電 池與將多晶石夕作為基板的太陽電池相比較，具有如下的特 徵’即，將入射的光能（optical energy )轉換為電能（dectrical energy)的轉換效率高。 為了製造無位錯的高品質的結晶，一般藉由柴氏法 (Czochralskimethod)來製造上述單晶矽，但^利'用柴氏 法的製造過程存在成本（cost)升高的問題。 另一方面，作為製造多晶矽的方 ,χ ^ ^ /堯缉法（cast method)已為人所知（例如專利文獻 於利用洗鑄法的多晶石夕的禱造過程中 雜劑於坩堝中凝 c度矽進行加熱熔解’均一地等摻 劑（d〇pant)，使上述高純度矽與上述摻 寻仙雜 4201247949 VI. Description of the Invention: [Technical Field] The present invention relates to a wafer and a method of manufacturing the same, and a method of casting a polycrystalline material. The present invention relates in particular to high strength. A method for casting a polycrystalline ingot of a polycrystalline ingot, and a polycrystalline wafer produced by cutting a polycrystalline block, and a cell The process or the module (m〇dule) has fewer scratches in the process, and the polycrystalline block is obtained by cutting the polycrystalline ingot. [Prior Art] At present, silicon crystal is mainly used as a substrate for the production of a solar cell. The germanium crystal has a single crystal and a polycrystal, and a solar cell using a single crystal germanium as a substrate is compared with a solar cell using polycrystalline as a substrate, and has the following feature that the incident optical energy is converted into The conversion efficiency of dectrical energy is high. In order to produce high-quality crystals without dislocation, the above-mentioned single crystal germanium is generally produced by the Czochralski method, but there is a problem that the manufacturing process by the Chai method has an increase in cost. On the other hand, as a method for producing polycrystalline germanium, a cast ^ ^ / cast method is known (for example, the patent document is used in the process of making a polycrystalline stone in the process of using a washing method. Condensed c degree 矽 is subjected to heat melting 'uniformly equal doping agent (d〇pant), so that the above-mentioned high-purity lanthanum is mixed with the above-mentioned
201247949t I Λ \J I 固。由於需要具有耐熱性以及形狀穩定性，因此，坩堝一 般使用石英。 藉由將單方向性凝固法應用於上述澆鑄法，而能夠獲 得結晶粒大的多晶矽。 然而，上述澆鎢法所鑄造的多晶矽的強度低，每當對 矽塊體（silicon block)進行切割來製造多晶矽晶圓時，存 在以下的問題，上述矽塊體是將矽鑄錠（silic〇ning〇t)予 以切斷而成。亦即，於晶圓切割步驟中，主要有固定磨粒 法與游離磨粒法，上述固定磨粒法是使用如下的線（wire) 來進行切割，該線是使包含鑽石（diam〇nd)等的磨粒固定 於包含鋼線等的芯線（線材）的外周面而成，上述游離磨 粒法是使用含有磨粒的的漿料（slurry)與鋼線來進行切 割。然而，由於上述澆鑄法所鑄造的多晶矽的強度低，因 此，於利用固定磨粒法的高速切割過程中，會高概率 (probability)地在晶圓上產生劃痕，因此，必須進行利用 游離磨粒法的低速切f，j，存在如下的問題，即，切割步驟 的處理量（throughput)低。 夕又，對於在上述切割步驟中，未產生劃痕地被製造的 多晶晶圓而言’亦存在如下的問題，即，由於晶圓的強度 低因此，在接下來的用作太陽電池用的基板時的單元製 程、模組製程中，容易產生劃痕。 、 。尤其近年來，多晶晶圓的厚度逐步變薄，特別是當晶 圓的厚度為200 μιη以下時，晶圓切割步驟或上述單元掣 程、模組製程中關痕產生率升高，，針對此種晶圓 201247949 劃痕的對策的必要性逐步增加。 先前技術文獻 專利文獻 專利文獻1 :曰本專利特開平6_64913號公報 【發明内容】 本發明的目的在於提供可獲得強度高的多晶鑄錠的多 晶材料的鑄造方法。 曰^，本發明的目的在於提供如下的多晶晶圓，該多晶 明，旎夠於切割步驟中，以低劃痕產生率而被製造 ，且上 述皁元製程、模組製程中的劃痕的產生率亦低。 為了解決上述問題，本發明人反覆地進行了仔細研究。 —結果，本發明人獲得了如下的發現，即，僅於多晶鑄 的L邊。卩’使結晶粒彳$減小，藉此來使修邊部的強度提 尚，，而可使多晶塊體的切割時的劃痕產生率減小，而且 可使單元製程、模組製程中的多晶晶圓的劃痕產生率減小。 具體而言，本發明人發現：於後述的電磁鑄造法中， 對多晶材料的熔化液的冷卻速度進行控制，藉此，可僅使 多晶鑄錠的修邊部的結晶粒徑減小。 本發明是立足於上述發現的發明，本發明的宗旨 如下所述。 (1) 一種多晶晶圓，其特徵在於，其是矩形平板狀的 多晶晶圓，且於上述矩形的至少一條邊包括修邊部，該修 邊部的結晶粒徑為上述矩形的令心部的結晶粒徑的〇仍 倍〜0.5倍。 · 201247949 ~Τ X / ν/^/ΐί (2) 如上述（1)所述之多晶晶圓，其特徵在於：上 述修邊部的維氏硬度（Vickers hardness) (Ην)為上述矩 形的中心部的維氏硬度（Ην)的1.2倍〜5倍。 (3) 如上述（1)或（2)所述之多晶晶圓，其特徵在 於：上述修邊部的結晶粒徑為 5 mm以下。 ，（4)如上述（！）〜（3)中任一項所述之多晶晶圓， 其特徵在於：上述修邊部的維氏硬度（Hv)為議Ην以 上0 (5) —種多晶材料的鑄造方法，其特徵在於，將盔底 ，冷卻模具（mGld)配置於腔室（ehambe〇的感應線圈 内’藉由利用上述感應線圈的電磁感應加熱，於 ^述，卻模具㈣.好晶材料的熔化液，對上述熔化液進 二冷部使上雜化液凝固，—面朝下方抽出已凝固 ^上述溶化液’上述無底的冷卻模具的軸方向的至少一部 分在圓周方向上被分割為多個部分，其+，對上述溶化液 進行冷卻的速度為l〇〇°C/sec以上。 / (6)如上述（5)所述之多晶材料的_造方法，其 徵在於：將上述冷卻速度設為i⑻。c/see以上此了 上述修邊部的結晶粒徑控制為5mm以下。 r s Λ7 )rΓ種多晶晶圓的製造方法’其特徵在於：將上述 m 多晶㈣的鑄造方法所獲得的多晶鑄 割。刀斷且为割為多晶塊體，並對該多晶塊體進行切 (發明的效果） 201247949 根據本發明的鑄造方法，可獲得修邊部的強度高的多 晶禱鍵。 =述多晶鑄錠予以切斷而獲得的多晶塊體的修邊部 :強度局’因此，可使晶圓切割步驟中的劃痕的產生率減 因此，能夠利用固定磨粒法來進行高逮切 驟的處理量提高。 刀^步 又’由於對多晶塊體進行切割所得的多晶晶圓的修邊 ^的強度亦高’因此，太陽電池的製造步驟即單元製程、 中的晶圓的劃痕產生率亦減小，從而亦可使太陽 電池製造的良率提高。 而且即便於近年來的使晶圓的厚度變薄的製程 (process)中，亦可將切割步驟時的劃痕率抑制為 早。 一 彳<τ< 對於本發明的多晶晶圓而言，僅修邊部的結晶粒 八他4刀的結晶粒徑大，因此，可充分地使太陽電 池的轉換效率提高^ 【實施方式】 圖1是模式性地表示電磁鑄造法中所使用的電磁鑄造 裝置的一例的剖面圖。 如圖1所示’腔室1是以不受内部發熱影響的方式而 ，為雙重壁構造的冷卻容器，腔室1於中央部配置有冷卻 、’、2、感應線圈3、以及加熱器（heater) 4。 於圖不的例子中，冷卻模具2為銅的水冷筒體，且除 8 201247949 了上部之外，在圓周方向上被分割成多個部分且無底。 又’於圖示的例子中’感應線圈3是同芯地繞設 (circumferentially disposed)於冷卻模具2的外周側，且 利用同軸電纜（cable)(未圖示）而連接於電源。 於圖示的例子中，加熱器4是同芯地設置於冷卻模具 2的下方，對自冷卻模具2下拉的鑄錠5進行加熱，從而 使鑄錠5的下拉軸方向產生規定的溫度梯度。 以下例舉多晶石夕作為多晶材料，對本發明的禱造方 法進行說明。 為了使用圖1所示的裝置來鑄造多晶石夕，首先，將石夕 材料6裝人至冷卻模具2 ’接著’使交流電流流入至感應 線圈3。 u 、冷卻模具2於圓周方向上被分割，各分割片彼此電性 为離’因此，於各分則⑽成錢迴路（eu_t ， 該電流使冷卻模具2内產生磁場。 藉此，藉由電磁感應加熱來使石夕材料炫解，從而 石夕炫化液7。 此慝 祕〇 内_材料會因冷卻模具2的内壁 戶巧成的磁場與熔融矽表面的電流的電磁交互作用 imeraCti〇n)，2 仅方向内側的力’因此’上述㈣料會在林冷 態:熔解，從而防止上述㈣料受到來自冷 2具的雜質㈣，而且易於朝鑄錠5的下方下拉上述石夕 201247949 ，處，每當使熔融矽凝固時，使下拉裝置8朝下方移 動该下拉裝置8利用下部來保持著熔融♦與敏。隨著 上述下^置8遠離絲、《 3的下端，感應磁場變小， 朝向直徑方向内側的力變小’藉由冷卻 U的冷部效果，炫融石夕7自外周側起逐步凝固 朝下方=步將已凝固的熔融石夕 7抽出。 配合下拉裝置的朝向下方的移動，連續地將石夕材料追 加裝入至冷部模具2 ’繼續逐步财材料6轉及凝固， 藉此，能夠連續地鑄造多晶矽。 再者，將添加有摻雜劑的矽材料6予以裝入，藉此， 可對多晶矽晶圓的導電性進行控制。 λ於Ρ型多晶矽晶圓的鑄造過程中，可使用硼、鎵及鋁 等的熔融原料作為摻雜劑’ 型多晶矽晶圓的鑄造_ 中，可使㈣、坤及録等熔融原料作為摻雜劑。 此處，於本發明的鑄造方法中，每當使上述多晶材料 凝固時，重要的疋將多晶材料的溶化液的冷卻速度設為 100C/sec以上。多晶材料例如可設為多晶石夕。 又，所謂冷卻速度，是指於直至矽熔化液固化為止的 期間，每單位時間的溫度變化的平均值（t>c/sec)。 具體而言，使用如下的水冷模具，且將冷卻水的溫度 設為3〇t以下，藉此，可實現上述冷卻速度，上述水冷模 具使用有導熱良好的銅。 再者’冷卻速度較佳設為5〇〇°c/sec以下。 藉此，外周部由於經水冷的銅模具產生的急冷效果， 201247949 -Γ l\J / vpit (b)所示’而可製造如下的矽鑄錠9， 该石夕鑄錠9的修邊部1〇的結晶粒徑為5 _以下。 ff，石夕鑄錠9的中心部11的結晶粒徑為10mm〜20 〇10 八二f ’所謂粒徑，是指修邊部10或中心部11各自部 徑進ί測鏡來進行觀察’藉此來對結晶粒 ί者所的結晶粒呈放射狀的有規律的形狀。 入’所明修邊部10，如国_ 指在長方體的石夕鑄鍵9的與·造方二乂⑴，’是 或長方形）的面或⑽2 ^方㈣絲矩形（正方形 直徑方向的内側，i有自45條邊分別朝向矩形剖面的 面的各條邊的法線方向 =矩㈣ 位置條對角==置=:心 指包含長二：的 或長方形）的面或剖面中向f直的矩形（正方形 邊部10更靠中心〇側的=4中心位置〇，且比上述修 再者，所謂長方體、& 數學上的嚴密的形狀，包含具i製==非為 201247949 如上所述，本發明的鑄造方法所獲得的矽鑄錠9的修 邊部10的結晶粒徑小於中心部11的結晶粒徑。因此，該 矽鑄錠9的修邊部10的強度高於中心部1〇的強度。 此處，使用維氏硬度（Hv)作為表示強度的指標。維 氏硬度是使用維氏硬度計（三豐儀器股份有限公司製造： 微小硬度計MVK-G3 )，將負荷設為9.8 Ν且基於JIS Ζ 2244 (2009年）而求出的硬度。 藉由本發明的鑄造方法所獲得的矽鑄錠9的修邊部1〇 的維氏硬度（Hv)為中心部11的維氏硬度（Hv)的1.2 倍〜5倍。 稭此 接者，如圖3所示，將石夕鑄旋9予以切斷 製造多個長方體的矽塊體12。 如圖3所示’上述矽塊體12包含上述矽鑄錠9的修邊 部10與中心部11。亦即’矽塊體12包含：修邊部1〇，其 與鑄造方向（鑄造出鑄錠的方向）垂直的面或剖面，自^ 周中的一條邊或相鄰接的兩條邊的每一條，朝向矩形的面 的直徑方向内側而具有5 mm〜5cm的寬度；以及中心部 11，其為修邊部以外的部分，且處於比修邊部更靠矩形 面的中心側處。 矽塊體12是對上述矽鑄錠9進行分割而成’因 矽鑄錠9同樣地，修邊部1〇的維氏硬度比中心部，與 氏硬度大1.2倍〜5倍。 的維 接著，圖4(a)、® 4(b)是模式性地表示 形的圖，該情形是指以❹j面鱗造方向垂直 的情 戎，對 201247949 ~r X\j l 矽塊體12進行切割來製造矽晶圓l3。 如上所述，將本發明所獲得的石夕塊體12的修邊 作為開始進行切割的位置，藉此，該修邊部iq的強产古， 因此，即便於上述利用固定磨粒法的高速切割過程中又亦 割時產生於晶圓的劃痕減少，或者即便使晶圓的厚 度支薄地進行蝴’亦可使切割時產生於晶圓關痕減少。 此處’如圖4(a)、圖4(b)所示，多晶晶圓13為矩 形平板狀。 如圖4 (a)、圖4 (b)所示，本發明的多晶晶圓13 包含上述矽鑄錠9的修邊部1〇與中心部u❶亦即，本發 明的多晶晶圓13包含：修邊部1〇，自外周中的一條邊或 相鄰接的兩條邊的每-條’朝向矩形的晶圓的直徑方向内 側而具有5 mm〜5cm的寬度；以及中心部u，其為修邊 部10以外的部分，且處於比修邊部1〇更靠矩形的中心側 處。 此處’所謂晶圓的直徑方向，是指在與鑄造方向（鑄 造出鑄錠9的方向）垂直的矩形的面或剖面中，矩形的面 或剖面的各條邊的法線方向，相對於各條邊，上述矩形的 面的中心位置（矩形的兩條對角線的交點的位置）側為内 侧。 石夕晶圓13是與鑄造方向垂直地對矽塊體π進行切割 來製造的晶圓’因此’與矽鑄錠9以及矽塊體12同樣地， 修邊部10的結晶粒徑為中心部11的結晶粒徑的0.05倍〜 〇.5倍°具體而言’矽晶圓13的修邊部1〇的結晶粒徑為5 13 201247949 mm以下。 又，石夕晶圓13的修邊部10的維氏硬度（Hv)為中心 部η的維氏硬度㈤）的u倍〜5倍。具體而言， 部10的維氏硬度（Ην)為1100 (Ην)以上。 再者，如圖5(a)、圖5㈨中的多晶碎晶圓的上表 面的照片所示，於圖5 (a)所示的例子中，中心部u具 有放射狀的有規律的結晶粒’於圖5 (b)所示的例子中二 中心部11具有直線狀的有規律的結晶粒。 如上所述’由於本發明的多晶i圓的修邊部的強度 高，因此，太陽電池的製造步驟中的劃痕的產生率亦低。 又，由於中心部11的結晶粒經大，因此，本發明的多 晶晶圓與圖5 (c)所示的澆鑄法所製造的矽晶圓同等地， 太陽電池的轉換效率高。 實例 為了確認本發明的效果，使用圖1所示的鑄造裝置， 藉由上述鑄造方法來製造剖面為350 mmx500 mm的矩形 形狀的多晶矽鑄錠，接著由該鑄錠來製造多個多晶矽塊體。 此處，作為發明例1、發明例2，使用水冷模具，上述 水冷模具使用有導熱良好的銅，且將冷卻水的溫度設為 29°C，藉此，將上述冷卻速度設為150°C/sec ’對多晶矽進 行鑄造。 當將鑄造所得的矽鑄錠分割為矽塊體時，將包括圖5 (a)所示的剖面的矽塊體作為發明例卜將包括圖5 所示的剖面的矽塊體作為發明例2。201247949t I Λ \J I solid. Quartz is generally used because of its heat resistance and shape stability. By applying the unidirectional solidification method to the above casting method, polycrystalline germanium having a large crystal grain can be obtained. However, the polycrystalline silicon cast by the above-described tungsten casting method has low strength, and when the silicon block is cut to produce a polycrystalline silicon wafer, there is the following problem. The above-mentioned tantalum block is a tantalum ingot. Ning〇t) is cut off. That is, in the wafer cutting step, there are mainly a fixed abrasive method and a free abrasive method, and the above fixed abrasive method is performed by using a wire which is made to contain diamonds (diam〇nd). The abrasive grains are fixed to the outer peripheral surface of a core wire (wire) including a steel wire, and the free abrasive grain method is performed by using a slurry containing abrasive grains and a steel wire. However, since the polycrystalline silicon cast by the above casting method has low strength, scratches are generated on the wafer with high probability in the high-speed cutting process by the fixed abrasive method, and therefore, it is necessary to use the free grinding. The low speed cut f, j of the grain method has a problem that the throughput of the cutting step is low. Further, in the above-described dicing step, the polycrystalline wafer to be manufactured without scratches also has a problem that, since the strength of the wafer is low, it is used as a solar cell in the following. In the unit process and the module process of the substrate, scratches are likely to occur. , . In particular, in recent years, the thickness of the polycrystalline wafer is gradually thinned, especially when the thickness of the wafer is less than 200 μm, the wafer cutting step or the above-mentioned unit process, the module process, the rate of occurrence of the mark increases, The need for such a scratch on the wafer 201247949 is gradually increasing. CITATION LIST Patent Literature Patent Literature 1: JP-A-6-64913 SUMMARY OF THE INVENTION An object of the present invention is to provide a method for casting a polycrystalline material in which a polycrystalline ingot having high strength can be obtained. In view of the above, it is an object of the present invention to provide a polycrystalline wafer which is manufactured in a cutting step and has a low scratch generation rate, and which is described in the above-described soap cell process and module process. The rate of mark generation is also low. In order to solve the above problems, the inventors have conducted intensive studies repeatedly. - As a result, the inventors obtained the finding that it is only on the L side of the polycrystalline cast.卩 'Reducing the crystal grain 彳 $, thereby increasing the strength of the trimming portion, thereby reducing the occurrence of scratches during cutting of the polycrystalline block, and enabling the unit process and the module process The scratch generation rate of the polycrystalline wafer in the process is reduced. Specifically, the inventors have found that in the electromagnetic casting method described later, the cooling rate of the molten material of the polycrystalline material is controlled, whereby only the crystal grain size of the trimmed portion of the polycrystalline ingot can be reduced. . The present invention is based on the above findings, and the gist of the present invention is as follows. (1) A polycrystalline wafer characterized in that it is a rectangular flat polycrystalline wafer, and includes a trimming portion on at least one side of the rectangular shape, and a crystal grain size of the trimming portion is a rectangular shape The 结晶 of the crystal grain size of the heart is still ~0.5 times. (2) The polycrystalline wafer according to the above (1), characterized in that the Vickers hardness (Ην) of the trimming portion is the above rectangular shape The Vickers hardness (Ην) of the center portion is 1.2 times to 5 times. (3) The polycrystalline wafer according to the above (1) or (2), wherein the trimming portion has a crystal grain size of 5 mm or less. (4) The polycrystalline wafer according to any one of (3), wherein the trimming portion has a Vickers hardness (Hv) of less than or equal to 0 (5). A method for casting a polycrystalline material, characterized in that a helmet bottom and a cooling mold (mGld) are disposed in a chamber (in an induction coil of an ehambe〇) by electromagnetic induction heating using the above-mentioned induction coil, but the mold (4) a molten material of a good crystal material, wherein the molten liquid is introduced into the cold portion to solidify the upper hybrid liquid, and the solidified liquid is melted downward; at least a portion of the axial direction of the bottomless cooling mold is circumferentially The upper portion is divided into a plurality of portions, and the speed at which the molten solution is cooled is 10 ° C / sec or more. (6) The method for producing a polycrystalline material according to the above (5), The cooling rate is i (8). The crystal grain size of the trimming portion is controlled to be 5 mm or less. The method for producing a polycrystalline wafer of rs Λ 7 ) r is characterized in that the m is Polycrystalline casting obtained by the casting method of polycrystalline (d). The cutter is cut into a polycrystalline block, and the polycrystalline block is cut (effect of the invention) 201247949 According to the casting method of the present invention, a polycrystalline prayer key having a high strength of the trimming portion can be obtained. = the trimming portion of the polycrystalline block obtained by cutting the polycrystalline ingot: the strength portion. Therefore, the rate of occurrence of scratches in the wafer cutting step can be reduced, and thus the fixed abrasive method can be used. The throughput of high catching and cutting is increased. The step of the knife is also 'the strength of the trimming of the polycrystalline wafer obtained by cutting the polycrystalline block is high'. Therefore, the manufacturing process of the solar cell, that is, the scratch rate of the wafer in the unit process and the wafer is also reduced. Small, which can also increase the yield of solar cell manufacturing. Further, even in a process in which the thickness of the wafer is reduced in recent years, the scratch rate at the cutting step can be suppressed to be early. In the polycrystalline wafer of the present invention, only the crystal grain size of the dicing portion of the dicing portion is large, so that the conversion efficiency of the solar cell can be sufficiently improved. FIG. 1 is a cross-sectional view schematically showing an example of an electromagnetic casting apparatus used in an electromagnetic casting method. As shown in Fig. 1, the chamber 1 is a cooling container having a double wall structure in such a manner that it is not affected by internal heat generation, and the chamber 1 is provided with cooling, ', 2, induction coil 3, and heater at the center portion ( Heater) 4. In the example of Fig. 5, the cooling mold 2 is a water-cooled cylinder of copper, and is divided into a plurality of portions and has no bottom in the circumferential direction except for the upper portion of 8 201247949. Further, in the illustrated example, the induction coil 3 is disposed coaxially on the outer peripheral side of the cooling mold 2, and is connected to the power source by a coaxial cable (not shown). In the illustrated example, the heater 4 is disposed below the cooling mold 2 in the same core, and heats the ingot 5 pulled down from the cooling mold 2 to cause a predetermined temperature gradient in the pull-down axial direction of the ingot 5. The method of praying according to the present invention will be described below by exemplifying polycrystalline as a polycrystalline material. In order to cast the polycrystalline stone using the apparatus shown in Fig. 1, first, the stone material 6 is loaded to the cooling mold 2' and then an alternating current is supplied to the induction coil 3. u, the cooling mold 2 is divided in the circumferential direction, and each of the divided pieces is electrically separated from each other. Therefore, a gas circuit is formed in each of the fractions (10) (eu_t, which causes a magnetic field to be generated in the cooling mold 2. Thereby, by electromagnetic Induction heating to make the Shixi material dazzle, and thus Shi Xiyun liquid 7. This material will be electromagnetic interaction between the magnetic field on the inner wall of the cooling mold 2 and the current on the surface of the molten crucible imeraCti〇n ), 2 only the direction of the inner side of the force 'so the above (4) will be in the cold state of the forest: melting, thus preventing the above (4) material from receiving impurities from the cold (four), and easy to pull down the above-mentioned ingot 5 below the stone eve 201247949, At this time, each time the molten crucible is solidified, the pull-down device 8 is moved downward. The pull-down device 8 uses the lower portion to maintain the melt and the sensitivity. With the above-mentioned lower setting 8 away from the wire, the lower end of "3, the induced magnetic field becomes smaller, and the force toward the inner side in the diameter direction becomes smaller", by cooling the cold portion effect of U, the smelting stone eve 7 gradually solidifies from the outer peripheral side toward The lower = step extracts the solidified molten stone 7 . In conjunction with the downward movement of the pull-down device, the Shixia material is continuously loaded into the cold mold 2' to continue the solidification of the material 6 turns and solidification, whereby the polycrystalline silicon can be continuously cast. Further, the dopant material 6 is added, whereby the conductivity of the polysilicon wafer can be controlled. In the casting process of Ρ-type polycrystalline germanium wafers, molten materials such as boron, gallium, and aluminum can be used as the dopants for the doping 'polysilicon wafers', and the molten materials such as (4), Kun and Lu can be used as doping. Agent. Here, in the casting method of the present invention, each time the polycrystalline material is solidified, the important enthalpy is such that the cooling rate of the molten material of the polycrystalline material is 100 C/sec or more. The polycrystalline material can be, for example, a polycrystalline stone. Further, the cooling rate is an average value (t > c / sec) of temperature change per unit time until the enthalpy melt is solidified. Specifically, the water-cooling mold is used, and the cooling rate can be achieved by setting the temperature of the cooling water to 3 Torr or less. The water-cooling mold uses copper having good heat conductivity. Further, the cooling rate is preferably set to 5 〇〇 ° c / sec or less. Thereby, the simmering ingot 9 of the outer peripheral portion due to the quenching effect by the water-cooled copper mold, as shown in 201247949 - Γ l\J / vpit (b), the trimming portion of the shovel ingot 9 The crystal grain size of 1 〇 is 5 _ or less. Ff, the crystal grain size of the center portion 11 of the Shixi ingot 9 is 10 mm to 20 〇10 八 f 'the particle size, which means that the trimming portion 10 or the center portion 11 has its own diameter into the mirror for observation. Thereby, the crystal grains of the crystal grains are radially in a regular shape. Into the edging part 10, such as the country _ refers to the face of the stone slab key 9 in the rectangular parallelepiped and the square (1), 'is or rectangular' face or (10) 2 ^ square (four) wire rectangle (the inner side of the square diameter direction) i has the normal direction of each side of the face from the 45 sides facing the rectangular section = moment (four) position bar diagonal == set =: the heart refers to the face of the long two: or rectangle) or the straight line to the straight The rectangular shape (the square side portion 10 is closer to the center side of the center of the =4 center position 〇, and compared with the above-mentioned repair, the so-called cuboid, & mathematically strict shape, including the system == non is 201247949 as described above, The crystal grain size of the trimming portion 10 of the tantalum ingot 9 obtained by the casting method of the present invention is smaller than the crystal grain size of the center portion 11. Therefore, the trimming portion 10 of the tantalum ingot 9 has a higher strength than the center portion 1 Here, the Vickers hardness (Hv) is used as an index indicating the strength. The Vickers hardness is measured by a Vickers hardness tester (manufactured by Mitutoyo Instruments Co., Ltd.: Micro hardness tester MVK-G3), and the load is set to 9.8. And the hardness obtained based on JIS Ζ 2244 (2009). By the present invention The Vickers hardness (Hv) of the trimming portion 1 of the tantalum ingot 9 obtained by the method is 1.2 times to 5 times the Vickers hardness (Hv) of the center portion 11. The straw is as shown in FIG. The stone block 12 is cut and manufactured to cut a plurality of rectangular parallelepiped blocks 12. As shown in Fig. 3, the above-mentioned block body 12 includes the trimming portion 10 and the center portion 11 of the above-described tantalum ingot 9. The block body 12 includes: a trimming portion 1〇, a face or a cross section perpendicular to the casting direction (the direction in which the ingot is cast), one edge from the circumference or each of the two adjacent sides, toward the rectangle The surface of the face has a width of 5 mm to 5 cm in the diametrical direction; and a central portion 11, which is a portion other than the trimming portion, and is located at the center side of the rectangular surface than the trimming portion. The bismuth ingot 9 is divided into the same shape. In the same manner, the Vickers hardness of the edging portion 1 比 is 1.2 times to 5 times larger than the center portion, and the dimension is 1.2 times to 5 times. , ® 4(b) is a diagram that schematically represents the shape. This case refers to the cutting of the 201247949 ~r X\jl 矽 block 12 in the direction perpendicular to the 鳞j face scale. To manufacture the tantalum wafer l3. As described above, the trimming of the Shishi block 12 obtained by the present invention is used as the position at which the cutting is started, whereby the trimming portion iq is strong, so even in the above In the high-speed cutting process using the fixed abrasive method, the scratches generated on the wafer during the cutting process are reduced, or even if the thickness of the wafer is thinned, the wafer marks can be reduced during the cutting. As shown in Fig. 4 (a) and Fig. 4 (b), the polycrystalline wafer 13 has a rectangular flat shape. As shown in Fig. 4 (a) and Fig. 4 (b), the polycrystalline wafer 13 of the present invention comprises The trimming portion 1〇 and the center portion u❶ of the above-described tantalum ingot 9, that is, the polycrystalline wafer 13 of the present invention comprises: a trimming portion 1〇, from one side of the outer circumference or each of two adjacent sides The strip has a width of 5 mm to 5 cm toward the inner side in the diameter direction of the rectangular wafer; and a central portion u which is a portion other than the trimming portion 10 and is located at a center side of the rectangle more than the trimming portion 1〇 . Here, the diametrical direction of the wafer means a normal direction or a cross section perpendicular to the casting direction (the direction in which the ingot 9 is cast), and the normal direction of each side of the rectangular surface or the cross section is relative to each The strip side is the inner side of the center position of the rectangular surface (the position of the intersection of the two diagonal lines of the rectangle). The Shihwa wafer 13 is a wafer which is manufactured by cutting the tantalum block π perpendicularly to the casting direction. Therefore, similarly to the tantalum ingot 9 and the tantalum block 12, the crystal grain size of the trimming portion 10 is the center portion. The crystal grain size of 11 is 0.05 times to 5. 5 times. Specifically, the crystal grain size of the trimming portion 1 of the wafer 13 is 5 13 201247949 mm or less. Further, the Vickers hardness (Hv) of the trimming portion 10 of the Shihwa wafer 13 is u times to 5 times the Vickers hardness (f) of the center portion η. Specifically, the Vickers hardness (Ην) of the portion 10 is 1100 (Ην) or more. Further, as shown in the photograph of the upper surface of the polycrystalline wafer in FIGS. 5(a) and 5(9), in the example shown in FIG. 5(a), the central portion u has a radial regular crystal. In the example shown in Fig. 5(b), the two central portions 11 have linear regular crystal grains. As described above, since the trimming portion of the polycrystalline i-circle of the present invention has high strength, the rate of occurrence of scratches in the manufacturing process of the solar cell is also low. Further, since the crystal grains of the center portion 11 are large, the conversion efficiency of the solar cell is high as in the case of the tantalum wafer manufactured by the casting method shown in Fig. 5(c). EXAMPLES In order to confirm the effect of the present invention, a rectangular shaped polycrystalline ingot having a cross section of 350 mm x 500 mm was produced by the above casting method using the casting apparatus shown in Fig. 1, and then a plurality of polycrystalline crucible blocks were produced from the ingot. Here, as the invention example 1 and the invention example 2, a water-cooling mold is used, and the water-cooling mold is made of copper having good heat conductivity, and the temperature of the cooling water is 29° C., whereby the cooling rate is 150° C. /sec ' Casting polycrystalline germanium. When the cast ingot obtained by casting is divided into a tantalum block, the tantalum block including the cross section shown in Fig. 5 (a) is taken as an invention example, and the tantalum block including the cross section shown in Fig. 5 is taken as the inventive example 2 .
201247949 A 又，作為比較例1，使用水冷模具，上述水冷 用有導熱良好的銅，且將冷卻水的溫度設為此， 將上述冷卻速度設為2〇°c/sec來進行鑄造，製造如下s的多 晶石夕晶圓’該多晶碎晶圓的正方形的相鄰接的兩條邊的^ 邊部的結晶粒徑比中心部的結晶粒徑稍小。 少 此外，作為比較例2，準備將如下的多晶矽鑄錠予以 切斷所得的多晶矽塊體，上述多晶矽鑄錠是藉由利用澆 法的先前的方法來製造。 & ’ 首先，為了對晶圓切割步驟中的劃痕的產生率進行坪 價，分別製造10個與發明例1、發明例2、比較例丨、及 比較例2相關的多晶矽塊體，對該多晶矽塊體進行切割來 製造500塊多晶石夕晶圓，接著對劃痕的產生概率進行評價。 利用固定磨粒法來進行切割，且使用如下的線，該線 固定有平均粒徑為20 μιη的鑽石作為磨粒。再者，晶圓的 修邊部成為切割的開始口。 首先，關於切斷成厚度為200 μιη的多晶石夕晶圓的情 形’使切割的速度於〇.2mm/s〜l.〇mm/s的範圍内變化而 進行切割（表1)〇 接著’將切割速度設為0.6 mm/s ’使製造的晶圓的厚 度於100 μιη〜200 μιη的範圍内變化，對劃痕的產生率進 行評價（表2)。 將評價結果分別歸納於表1、表2。 15 201247949 [表i] 劃痕率 切斷速度（mm/s) 0.2 0.4 0.6 0.8 1.0 . 發明例1 (%) 0.20 0.30 0.33 0.50 0.89 發明例2 (%) 0.23 0.32 0.35 0.56 0.98 比較例1 (%) 4.1 2.9 3.8 5.7 4.6 比較例2 (%) 3.9 4.1 4.8 5.5 6.3 [表2] 劃痕率 晶圓厚度（μπι) 100 130 160 180 200 發明例1 (%) 2.20 1.25 0.52 0.50 0.33 發明例2 (%) 2.30 1.28 0.59 0.52 0.35 比較例1 (%) 8.9 5.9 5.5 4.9 3.8 比較例2 (%) 9.9 6.3 5.6 5.5 4.8 接著，進行如下的測試，該測試是對發明例1、發明 例2、比較例1及比較例2的各10塊晶圓的強度進行測定。 關於強度，根據上述維氏硬度（JISZ 2244: 2009年），對 晶圓的修邊部與中心部的各個強度進行評價。 又，根據上述測定方法，對發明例1、發明例2、比較 例1及比較例2的各10塊晶圓的修邊部與中心部的各個結 晶粒徑進行評價。 表3中表示10塊晶圓的維氏硬度（Hv)的平均值以 及結晶粒徑的平均值。 [表3] 維氏硬度（Hv) 結晶粒徑（mm) 修邊部 中心部 修邊部 中心部 發明例1 1300 1010 3.5 15.2 發明例2 1410 995 2.9 16.4 比較例1 980 975 24.5 29.5 比較例2 1010 1000 16.8 19.6 16 201247949t201247949 A Further, as a comparative example 1, a water-cooling mold is used, and the water-cooling mold has copper having good heat conductivity, and the temperature of the cooling water is set to be 2, and the cooling rate is 2 〇 ° c/sec. The polycrystalline quartz wafer of s' has a crystal grain size smaller than the crystal grain size of the center portion of the two adjacent sides of the square of the polycrystalline wafer. Further, as Comparative Example 2, a polycrystalline germanium block obtained by cutting a polycrystalline germanium ingot obtained by a conventional method using a casting method was prepared. & ' First, in order to perform the valence of the scratch generation rate in the wafer dicing step, 10 polycrystalline germanium blocks related to the inventive example 1, the inventive example 2, the comparative example 丨, and the comparative example 2 were respectively produced, and The polycrystalline germanium block was cut to fabricate 500 polycrystalline wafers, and then the probability of occurrence of scratches was evaluated. The cutting was carried out by a fixed abrasive method, and a wire having an average particle diameter of 20 μη as an abrasive grain was used. Furthermore, the trimming portion of the wafer serves as a starting port for cutting. First, in the case of cutting into a polycrystalline wafer wafer having a thickness of 200 μm, the cutting speed was changed within a range of 〇.2 mm/s to 1.mm/s (Table 1). 'The cutting speed was set to 0.6 mm/s', and the thickness of the manufactured wafer was changed within the range of 100 μm to 200 μm, and the occurrence rate of scratches was evaluated (Table 2). The evaluation results are summarized in Tables 1 and 2. 15 201247949 [Table i] Scratch rate cutting speed (mm/s) 0.2 0.4 0.6 0.8 1.0 . Inventive Example 1 (%) 0.20 0.30 0.33 0.50 0.89 Inventive Example 2 (%) 0.23 0.32 0.35 0.56 0.98 Comparative Example 1 (%) 4.1 2.9 3.8 5.7 4.6 Comparative Example 2 (%) 3.9 4.1 4.8 5.5 6.3 [Table 2] Scratch rate Wafer thickness (μπι) 100 130 160 180 200 Inventive Example 1 (%) 2.20 1.25 0.52 0.50 0.33 Inventive Example 2 ( %) 2.30 1.28 0.59 0.52 0.35 Comparative Example 1 (%) 8.9 5.9 5.5 4.9 3.8 Comparative Example 2 (%) 9.9 6.3 5.6 5.5 4.8 Next, the following test was carried out for the inventive example 1, the inventive example 2, and the comparative example. The strength of each of the ten wafers of 1 and Comparative Example 2 was measured. Regarding the strength, each strength of the trimming portion and the center portion of the wafer was evaluated based on the above Vickers hardness (JIS Z 2244: 2009). Further, according to the above-described measuring method, the crystal grain size of each of the trimming portion and the center portion of each of the ten wafers of Invention Example 1, Invention Example 2, Comparative Example 1, and Comparative Example 2 was evaluated. Table 3 shows the average value of the Vickers hardness (Hv) of the ten wafers and the average value of the crystal grain size. [Table 3] Vickers hardness (Hv) Crystal grain size (mm) Center portion of trimming portion center trimming portion Invention Example 1 1300 1010 3.5 15.2 Invention Example 2 1410 995 2.9 16.4 Comparative Example 1 980 975 24.5 29.5 Comparative Example 2 1010 1000 16.8 19.6 16 201247949t
• λ. I ^/λ X 接著，當使用上述發明例丨、發明例2、比較例1及比 較例2的各500塊晶圓來製造太陽電池時，對單元製程或 模組製程中的晶圓的劃痕產生率進行評價。 將s平價結果表示於表4中。 [表4] 劃很產生率（％、 發明例1 0.2 發明例2 0.3 比較例1 1.5 比較例2 2.0 接著，對使用發明例卜發明例2、比較例！及比較例 2的500塊晶圓來製造的太陽電池的轉換效率進行評價。 此處’太陽電池的轉換效率由如下的比（E2/Ei) xl〇〇 (%)來定義，該比（E2/E1) xlOO (%)是照射至太陽電 池的單元每單位面積的光能E1與自單元每單位面積獲得 的轉換後的電能E2之比。 表5中表示評價結果。 [表5] 轉換效率（％) 發明例1 16.1 發明例2 16.2 比較例1 16.0 比較例2 16.1 如表1、表2所示，對於發明例1、發明例2的石夕塊體 而言，即便高速地進行切割，亦可將劃痕的產生率抑制為 17 201247949 低產生率，而且即便當切割為200 μπι以下的厚度的晶圓 時，亦可將劃痕的產生率抑制為低產生率。 又，如表3所示，可知對於發明例1、發明例2的多 晶矽晶圓而言，僅修邊部的維氏硬度高，該修邊部的維氏 硬度為中心部的維氏硬度的1.2倍〜5倍。因此，可知： 發明例1、發明例2的多晶矽晶圓的強度高。 此外，可知由於發明例1、發明例2的多晶晶圓的強 度高，因此，如表4所示，製造太陽電池時的單元製程、 模組製私·中的晶圓的劃痕的產生率亦低。 而且，對於發明例1、發明例2的晶圓而言，僅修邊 部的強度高，中心部的強度低。亦即，由於僅修邊部的結 晶粒徑小’中心部的結晶粒徑大，因此，如表5所示，使 用發明例1、發明例2的晶圓來製造的太陽電池的轉換效 率，與使用比較例的晶圓來製造的太陽電池的轉換效率相 等。 【圖式簡單說明】 圖1是表示電磁鑄造法中所使用的裝置的一例的剖面 圖。 圖2 (a)是本發明的鑄造方法所獲得的矽鑄錠的概略 立體圖。圖2(b)是本發明的鑄造方法所獲得的石夕鑄錠的 概略俯視圖。 圖3是模式性地表示將本發明的鑄造方法所獲得的石夕 鑄錠予以切斷，接著分割為多個石夕塊體的情形的圖。 圖4 (a)、圖4 (b)是模式性地表示對矽塊體進行切 201247949 割來製造矽晶圓的情形的圖。 圖5 (a)、圖5 (b)是表示本發明的多晶矽晶圓的照 片的圖。圖5 (c)是表示澆鑄法所獲得的多晶矽晶圓的照 片的圖。 【主要元件符號說明】 I :腔室 2:冷卻模具 3 :感應線圈 4 :加熱器 5 :鑄疑 6 ·發材料 7 :熔融矽 8:下拉裝置 9 :鑄錠 10 :修邊部 II :中心部 12 :多晶塊體 13 .多晶晶圓 0 :中心位置 19• λ. I ^/λ X Next, when the solar cell is manufactured using the 500 wafers of the above-described invention example, invention example 2, comparative example 1, and comparative example 2, the crystal in the unit process or the module process The round scratch generation rate was evaluated. The s parity results are shown in Table 4. [Table 4] Very high production rate (%, Inventive Example 1 0.2 Inventive Example 2 0.3 Comparative Example 1 1.5 Comparative Example 2 2.0 Next, 500 wafers using Invention Example 2, Comparative Example! and Comparative Example 2 were used. The conversion efficiency of the manufactured solar cell is evaluated. Here, the conversion efficiency of the solar cell is defined by the ratio (E2/Ei) xl 〇〇 (%), which is the irradiation (E2/E1) xlOO (%) The ratio of the light energy E1 per unit area of the cell to the solar cell to the converted electric energy E2 obtained per unit area from the cell. The evaluation results are shown in Table 5. [Table 5] Conversion efficiency (%) Inventive Example 1 16.1 Example of invention 2 16.2 Comparative Example 1 16.0 Comparative Example 2 16.1 As shown in Tables 1 and 2, in the case of the invention examples 1 and 2, the occurrence rate of the scratch can be suppressed even if the cutting is performed at a high speed. It is a low generation rate of 17 201247949, and even when the wafer is cut to a thickness of 200 μm or less, the occurrence rate of the scratch can be suppressed to a low generation rate. Further, as shown in Table 3, it is known that the invention example 1 is In the polycrystalline germanium wafer of Inventive Example 2, only the trimming portion has a high Vickers hardness. The Vickers hardness of the edging portion is 1.2 to 5 times the Vickers hardness of the center portion. Therefore, it is understood that the polycrystalline silicon wafers of the invention examples 1 and 2 have high strength. Since the polycrystalline wafer of Example 2 has high strength, as shown in Table 4, the rate of occurrence of scratches in the cell process for manufacturing the solar cell and the wafer in the module manufacturing process is also low. 1. In the wafer of the second invention, only the trimming portion has high strength and the center portion has low strength. That is, since only the crystal grain size of the trimming portion is small, the crystal grain size of the center portion is large. As shown in Table 5, the conversion efficiency of the solar cell manufactured using the wafers of Inventive Example 1 and Inventive Example 2 was equal to the conversion efficiency of the solar cell manufactured using the wafer of the comparative example. [Simplified Schematic] FIG. Fig. 2(a) is a schematic perspective view of a tantalum ingot obtained by the casting method of the present invention, and Fig. 2(b) is a perspective view of the casting method of the present invention. A schematic top view of the Shixi ingot. Figure 3 is a schematic Fig. 4 (a) and Fig. 4 (b) schematically show the confrontation of the Shih-ingot ingot obtained by the casting method of the present invention, and then divided into a plurality of stone blocks. Fig. 5(a) and Fig. 5(b) are diagrams showing photographs of a polysilicon wafer of the present invention, and Fig. 5(c) is a view showing a casting method. A photograph of a photograph of the obtained polycrystalline silicon wafer. [Description of main component symbols] I: Chamber 2: Cooling mold 3: Induction coil 4: Heater 5: Casting 6 • Hair material 7: Melting 矽 8: Pull-down device 9: Ingot 10: trimming portion II: center portion 12: polycrystalline block 13. polycrystalline wafer 0: center position 19