201100788 六、發明謂:明： 【發明所屬之技術領域】 本發明係有關於經由使紅外線透 結晶矽晶圓等之多結晶晶圓内之：-太陽電池用多 【先前技術】 、万法。 專利文獻1所揭示之方法係使紅外 CCD攝影檣姐* 、、裏…、射在矽晶圓，利用 Ο 如機對透過之紅外線進行攝影 利用 利用影像處理而檢測微破裂等之缺陷。&代攝影影像 4::射?:Γ獻2所揭示之方法是從多結晶晶圓之表面和 月m線’利用紅外線攝影機對來自表面之紅外線反 射先和來自背面之紅外線透過光進行攝影，並個來自表面 和背面之影像資料㈣較結果，檢測多結晶晶_部之破裂 缺陷。 然、而，在檢測對象為多結㈣晶圓之情況，#利用一般的 〇紅外線透過光之攝影手法時，會亦將涵蓋結晶方向、結晶邊 界或其輪廓之結晶樣式取入為影像，因此在影像處理之過程 中，結晶樣式和缺陷之識別將較為困難，而容易發生誤檢測 或忽視缺陷。 [先前技術文獻] [專利文獻] 專利文獻1 :曰本專利特開2007-258555號公報 專利文獻2 :日本專利特開2〇〇7_218638號公報 099117151 3 201100788 【發明内容】 ' (發明所欲解決之問題） 本發明之目的係在攝影過程中使涵盖多結晶晶圓之結晶 方向、結晶邊界或其輪廓之結晶樣式變淡，而確實地檢測多 結晶晶圓内之缺陷。 (解決問題之手段） 根據上述課題，本發明人對多結晶晶圓照射紅外線，觀測 其透過紅外線，而重複進行此種實驗。其結果是獲得以下之 見解。亦即，當在紅外線之照射位置直接觀測透過多結晶晶 圓之紅外線時，攝影影像之多結晶晶圓之結晶樣式無法變 淡。但是，當使紅外線之照射位置、和所透過之紅外線之觀 察位置、亦即攝影機之攝影位置離開適當之距離時，多結晶 晶圓之結晶樣式可變淡，且可只使多結晶晶圓内之缺陷亮度 與其他正常部分之亮度不同。本發明係根據此種見解而完 成。 為達成上述目的，本發明係揭示以下内容。 (1)一種多結晶晶圓之檢查方法，其具有： 從光軸被配置成通過多結晶晶圓上之照射位置的光源，朝 向上述照射位置照射紅外線之步驟； 使紅外線從上述照射位置射入，在上述多結晶晶圓内部重 複折射和反射，而從朝上述多結晶晶圓之面方向離開上述照 射位置既定距離之上述多結晶晶圓上之攝影位置射出後，藉 099117151 201100788 由對上述攝影位置攝影之攝影機而加以攝影之步驟；及 在由上述攝影機所獲得之攝影影像上，根據無缺陷部分和 缺陷部分之免度差異而檢測上述多結晶晶圓内之缺陷之步 驟。 (2)係在（1)之多結晶晶圓之檢查方法中，其中，上述攝影 位置係被設定在設定有上述照射位置的上述多結晶晶圓面 之相反侧之面。 Ο (3)係在（1)之多結晶晶圓之檢查方法中，其中，上述攝影 位置係被設定在設定有上述照射位置的上述多結晶晶圓面 之相同面。 (4) 係在（1)至（3)中任一項之多結晶晶圓之檢查方法中，其 中， 上述光源為單一光源， 上述光源之光軸係對於上述多結晶晶圓之表面呈傾斜，而 〇 可從上述照射位置延伸到上述攝影位置側。 (5) 係在（1)至（3)中任一項之多結晶晶圓之檢查方法中，其 中， 上述光源為對於上述攝影位置而大致對稱配置之複數光 源， 各個上述光源之上述光軸係對於上述多結晶晶圓之表面 以同一傾斜角傾斜，而可從各個上述照射位置延伸到上述攝 影位置侧。 099117151 5 201100788 (6) 係在（1)至（5)中任一項之多結晶晶圓之檢查方法中，其 中， 上述光源為線型光源’ 上述攝影機為線感測器型之攝影機， 上述攝影機用於檢測經圓柱型透鏡聚光之紅外線。 (7) 係在（1)至（5)中任一項之多結晶晶圓之檢查方法中，其 中， 上述光源為形成環型照射區域之環型光源， 上述攝影機為使環型上述照射區域之内側為攝影區域之 區域感測器型之攝影機， 上述攝影機用於檢測經放大用透鏡聚光之上述紅外線。 (發明效果） 依照本發明之多結晶晶圓之檢查方法，從照射位置射入到 多結晶晶圓之紅外線係在多結晶晶圓内重複地反射或折 射，從在多結晶晶圓之面方向離開照射位置既定距離後之多 結晶晶圓上之攝影位置射出。利用攝影機對從該攝影位置射 出之紅外線進行攝影，而可獲得使結晶樣式變淡且可明確地 識別缺陷存在之攝影影像，可容易且確實地進行缺陷之檢 測。 具體而言，當在多結晶晶圓未存在有缺陷之情況時，由於 紅外線在多結晶晶圓内重複地反射或折射，因而到達攝影位 置之紅外線強度大致均一，幾乎不會受到結晶樣式之影響， 099117151 6 201100788 因此由攝影機所獲得之攝影影像將成為不會反映多結晶晶 圓之結晶樣式之均一亮度影像。 然而，當多結晶晶圓内存在有缺陷之情況時，缺陷將使紅 外線亂反射，到達攝影位置之紅外線的強度會變成不均一。 因此，在由攝影機所獲得之攝影影像上，缺陷將以與不存在 缺陷之情況相較下亮度不同之區域形式出現。如此，依照本 發明，由攝影機所獲得之攝影影像大致不會受到涵蓋多結晶 〇 晶圓之結晶方向、結晶邊界或其輪廓之結晶樣式的影響，因 為僅缺陷與沒有缺陷部分之亮度不同，因此可確實地檢測多 結晶晶圓内之缺陷。 【實施方式】 圖1和圖2係表示用以實施本發明多結晶晶圓1之檢查方 法的光學系統。圖1係表示檢查方向（多結晶晶圓1之搬運 方向)A從右向左狀態的光學系統之側視圖，圖2係表示檢 〇 查方向A為從紙面朝向紙面近前狀態的光學系統之前視圖。 參照圖1、圖2，說明用以實施本發明多結晶晶圓1之檢 查方法的光學系統。 首先，從被配置在多結晶晶圓1下面側之線型光源2，朝 向多結晶晶圓1之線狀照射位置P1照射沿與多結晶晶圓1 之搬運方向A相正交之方向延伸之線狀紅外線3。此時，以 通過照射位置P1之光源2之光軸相對多結晶晶圓1之表面 之法線nl傾斜之方式，配置光源2。具體而言，光源2之 099117151 7 201100788 光轴係對法線nl形成傾斜角α，以使光源2所射出之紅外 線3從照射位置Ρ1側延伸到攝影位置Ρ2侧。 此種線型光源2可藉由將複數紅外線發光二極體直線式 地配置、或使棒狀之紅外線光源和形成有線狀缝隙之光源蓋 體之組合而構成。 如圖3模式性所示，從照射位置Ρ1射入之紅外線3係在 多結晶晶圓1之内部重複地反射和折射，又在多結晶晶圓1 之表面和背面重複地反射而到達攝影位置Ρ2。到達攝影位 置Ρ2之紅外線3 —部分進行反射，而一部分則直接從多結 晶晶圓1之表面射出。其中，從攝影位置Ρ2射出之紅外線 3係利用光軸7被配置成通過攝影位置Ρ2之攝影機6而進 行攝影，並利用攝影機6獲得攝影影像。此處，該攝影位置 Ρ2係被設定在沿多結晶晶圓1之面方向離開照射位置Ρ1既 定距離D後之位置處。 本貫施形態中’攝影機6係相對多結晶晶圓1而被配置在 光源2之相反側。另外，該攝影機6之光軸7通過攝影位置 Ρ2，相對多結晶晶圓1之表面呈垂直。 線狀照射之紅外線3之波長最好為適合檢測内部缺陷之 波長、例如，0.7 # m〜2.5 // m之波長區域。另外，攝影機6 亦最好在此波長區域具有良好之靈敏度。 攝影位置P2係被設定在離開照射位置P1既定距離D後 之位置處。該距離D可依照多結晶晶圓1之結晶構造或其 099117151 8 201100788 厚度等而設定，可設定在結晶樣式變淡之最佳位置處。 另外，本發明之檢查方法最好以厚度0.1〜0.25mm之多結 晶晶圓1為對象。其原因在於，當多結晶晶圓1之厚度越厚， 紅外線3在多結晶晶圓1之内部越被折射反射而吸收，會使 攝影機6所攝影之紅外線3強度降低，無法獲得明顯之攝影 ' 影像。若多結晶晶圓1之厚度變薄，紅外線3到達攝影位置 P2為止所發生之折射或反射之次數將變少，攝影機6所獲 〇 得之攝影影像會殘留結晶樣式。 另外’光源2之光軸對多結晶晶圓1表面之法線nl之傾 斜角α最好設定在20。以上40。以下之範圍。其原因在於， 在傾斜角α未滿20。時，紅外線3從照射位置ρι到達離開 既定距離D後之攝影位置p2所需要之折射·反射之次數: 變大，而使攝影機6所攝影之紅外線3強度降低，無法獲得 明顯攝影影像。在傾斜肖α大於2G。時，減地紅外線^ ❾達攝〜位置P2所需要之折射.反射之次數將變少呈〜 像會殘留結晶樣式。 的的 二：步，照射位置ρι和攝影位置?2之間的既定距離〇 取好叹疋在1〜3mm。當既定距離D比lrnm還短時，紅外 到達攝办位置P2所需要之折射.反射之次數將變少，攝 衫衫像會殘留結晶樣式。當既定雜D比3咖還長時，折 射·反射之次數將變大’攝影機6所攝影之紅外線3強度會 降低，而無法獲得明顯之攝影影像。 099117151 9 201100788 在本發明之多結晶晶圓1之檢查方法十，為了使結晶樣式 的影響變小且可以獲得明顯之攝影影像，而在上述^圍内適 當地設定上述多結晶晶圓1之厚度、傾斜角α、既定距離p。 在用以實施如上述構成之多結晶晶圓丨之檢查方法的光 學系統中，通過多結晶晶圓1中不具缺陷之無缺陷區威的紅 外線3，係在複數個隨機存在之結晶粒之結晶方向或、结晶之 邊界重複地折射或反射，而到達攝影位置Ρ2。重複複數次 隨機之折射或反射之紅外線3，在到達離開照射位置ρ1既 定距離D後之攝影位置P2時各個結晶粒之折射.反射的影 響將互相抵銷，因此利用攝影機6在攝影位置p2攝影到之 攝影影像將成為具有均一亮度之線狀攝影影像。 另一方面，當多結晶晶圓1存在有缺陷4之情況時，則與 上述不同，紅外線3在缺陷4將發生亂反射或被吸收，因此 在攝影位置P2所攝影到之攝影影像會出現由於缺陷4造成 之陰影或明亮部分。由於該缺陷4所造成之陰影或明亮部分 係與由通過上述無缺陷區域之紅外線3所形成之攝影影像 有不同亮度，因此經由比較兩者亮度而可檢測缺陷4。 在搬運方向A搬運多結晶晶圓丨並連續重複進行以上步 驟’而可獲得具有如圖4A、圖犯所示面積之攝影影像。 圖4A、圖4B係表示對透過含缺陷4之區域之紅外線3 進行攝影的攝影機6之攝影影像。 圖4A中，在形成通過無缺陷區域之紅外線3的均—韋声 099117151 201100788 之背景影像，形成由通過缺陷4之紅外線3所產生之呈現較 暗陰影的亮影像。因此，經由從均一亮度之背景影像檢測亮 度不同之區域，而可簡單且確實地辨識缺陷4。另外，圖4A 係以厚度0.2mm之多結晶晶圓1為缺陷檢測對象並在既定 距離D = 2mm、傾斜角α =20。之設定條件下而得到之攝影 影像。 另外，本發明中，攝影位置Ρ2係被設定在沿多結晶晶圓 Ο 1之面方向離開照射位置Ρ1既定距離D=2mm後之位置 處。與此不同地’當將攝影位置設定在光源2之光軸延長線 上之既定距離D比1mm還短之位置p3處之情況時（參照圖 1) ’可在攝影位置P3攝影到在未充分重複折射或反射下而 射出之紅外線3，因此攝影影像將為受到結晶邊界之影響之 影像。因此，即使從通過含缺陷4之區域的紅外線3形成攝 影影像，亦將如圖4B所示，受到缺陷4影響之部分會被埋 Ο 於結晶樣式，而使缺陷4和結晶樣式之識別變為困難。 圖5係在多結晶晶圓1之下側將2個線型光源2相對攝影 位置P2上之法線(攝影機6之光軸7)而配置在線對稱之位置 處’從各光源2朝向多結晶晶圓1中2個位置處之照射位置 P1以不同之傾斜方向照射線狀紅外線3。另外，本例中，各 光源2之光轴與多結晶晶圓丨面所形成之傾斜角係被設定為 大致相同°依照此例’除了上述效果外，由於攝影機6可檢 測到之紅外線3的光量變多，可獲得明亮之攝影影像，因此 099117151 201100788 可容易對缺陷4進行檢測。 更進一步，圖6係利用圓柱型之透鏡8，將透過多結晶晶 圓1之紅外線3進行聚光，並利用線感測器型之攝影機6 檢測經聚光之紅外線3。在本例中，圓柱型之透鏡8係被配 置成其長度方向沿著線狀之紅外線3，紅外線3之成像沿多 結晶晶圓1之搬運方向放大。 如此，當紅外線3經由透鏡8放大時，而可容易由攝影機 6來檢測紅外線3，對於多結晶晶圓1之連續移動，誤檢測 或忽視情況亦可減少，故較為有利。附言之，透鏡8亦可如 圖1和圖2所示纟且入於單一光源2之例。 另外，具體之尺寸或光學系統之配置等可依照多結晶晶圓 1之厚度、紅外線3之波長區域、紅外線3之照射角度、攝 影機6之靈敏度等而設定在適當之數值。 其次，圖7係將光源2設為環型光源，將攝影機6設為區 域型之攝影機，並將光源2和攝影機6配置在對於多結晶晶 圓1而言為不同之面側。環型光源2對於攝影機6之光軸7 為同心狀配置。光源2之照射位置P1被設定在光源2所照 射紅外線3之光束呈現最大之位置處，其為比光源2之圓形 稱小之圓形。 依照本例，攝影位置(攝影區域)P2為區域型攝影機6之檢 測範圍，其如圖8所示，為在環型光源2之内側從照射位置 P1朝攝影機6之光轴7方向偏離距離D後之半徑較小的圓 099117151 12 201100788 内側。另外，可顏费卞 靜μ 置攝影機6之物鏡側之放大用凸 透鏡。另外，昭射仏m 丄 ‘、、、置1亦可以由環型之縫隙而形成。 了？列’來自光源2之紅外線3將從圓形之照射位置 1 進二晶㈣1之内部，在重複折射和反射後而到 達攝汾機6之圓形攝影位 置Ρ2内側’而由區域型之攝影機 6進灯攝影。 %型光源2從攝影機6之全部方向朝向多結晶晶圓^ 〇之照射位置P1照射紅外線3，因此即使在多結晶晶圓i内 之缺陷4不易從某—方向檢測時，亦可對該缺陷*進行檢 、J另卜、、&由&用區域型之攝影機6,而可將多結晶晶圓 1之檢查_(觀察範圍）設定在比線狀之檢查範圍還大之 面，因此可提高檢查效率。 另外’圖9係將環型光源2和區域型之攝影機6配置在多 結晶晶® 1之相同面側之實例。此例中，來自光源2之紅外 〇線3亦從圓形之照射位置ρι進入到多結晶晶圓κ内部， 在重複折射和反射後而到達圓形之攝影位置p2内側，並由 區域型之攝影機6進行攝影。 另外’當紅外線3在多結晶晶圓丨之表面反射而使攝影影 像不明顯時，亦可在攝影機6設置遮光用之遮光罩9，以防 止紅外線3之反射光直接射入攝影機6。另外，此例中亦可 利用環型之縫隙而形成照射位置P1。 依照圖9例’照射位置P1和攝影位置P2對於多結晶晶 099117151 13 201100788 圓1而言係在相同面，因此當多結晶晶圓1内缺陷4之部分 對紅外線3具有比其他正常部分還強之反射特性時，則可有 效且容易地對該缺陷4進行檢測。進而，即使在照射位置 P1或攝影位置P2無法設定在多結晶晶圓1之一面之狀態 下，亦可檢測缺陷4。 當然，關於上述圖1、圖2、圖5及圖6例，線型光源2 亦可配置在對多結晶晶圓1而言為與攝影機6相同側之面。 進而，來自線型光源2之紅外線3亦可如圖9中二點鏈線 所示，視需要利用光纖或丙烯酸樹脂板等之導光體，從多結 晶晶圓1之4個端面（4個侧面）中之至少1個端面朝向多結 晶晶圓1之内部進行照射。 在此情況下，依照圖5、圖6、圖7及圖9例，在多結晶 晶圓1之移動過程中，即使多結晶晶圓1之行進方向之前側 端緣部或行進方向之後側端緣部從1個光源2或光源2之一 部分脫離，若其他光源2或光源2之其他部分未從移動中之 多結晶晶圓1之端緣部脫離，則可以持續進行缺陷4之檢 測。因此，對於多結晶晶圓1之端緣部亦可進行缺陷4之檢 測。 以上例，係使紅外線3朝向多結晶晶圓1之照射位置P1 沿傾斜方向照射。因此，在紅外線3通過多結晶晶圓1之過 程中，折射及反射之機會比垂直方向之照射還多，可使紅外 線3較難受到結晶樣式的影響。但是，紅外線3之照射方向 099117151 14 201100788 亦可設定在對多結晶晶圓丨之照射位置P1為大致垂直方 向。即使如此設定，由於紅外線3在複數之結晶邊界反射， 因此紅外線3亦朝垂直方向以外之方向擴散，故經由對該擴 政之紅外線3進行攝影，而可獲得不受到結晶樣式影響之攝 影影像。 另外，以上例係使紅外線3於朝向多結晶晶圓1之照射位 置P1且指向攝影位置p2而傾斜之狀態進行照射。因此， Ο 多數紅外線3將經過多結晶晶圓1而朝向攝影位置P2，因 此可在攝影位置P2確保必要之光量。但是，即使紅外線3 經過多結晶晶圓1朝向攝影位置p2以外之方向，由於在多 結晶晶圓1内部之折射及反射和亂反射，而在攝影位置P2 會出現可攝影之光量，因此原理上可進行缺陷4之檢查。 多結晶晶圓1若在檢查位置停止，則可使攝影條件良好。 另一方面’在快門速度較為優先之情況時，亦可使多結晶晶 〇圓1連續地移動。另外，多結晶晶圓1之姿勢亦可非為水平， 可依照檢查空間而設定為垂直或傾斜狀態。 另外，本發明並不受限於矽晶圓，亦可利用在其他多結晶 構造之晶圓。 以上已參照特定之實施態樣詳細說明本發明，但本發明所 屬技術領域具通常知識者可明瞭在不脫離本發明之精神和 範圍内可施加各種之變更或修正。 本申'^案係根據2009年5月29日申請之日本專利案(特 099117151 15 201100788 願2009-130725)和2009年8月11日申請之日本專利案（特 願2009-186304)者，其内容已取入於此而作為參考。 (產業上之可利用性） 依照本發明之多結晶晶圓之檢查方法，可獲得使涵蓋多結 晶晶圓之結晶方向、結晶邊界或其輪廓之結晶樣式變淡而明 確地識別缺陷存在之攝影影像，並可容易且確實地進行缺陷 之檢測。 【圖式簡單說明】 圖1係用以實施本發明多結晶晶圓之檢查方法的光學系 統之側視圖。 圖2係用以實施本發明多結晶晶圓之檢查方法的光學系 統之前視圖。 圖3係多結晶晶圓内部之紅外線反射及折射狀況之說明 圖。 圖4 A係本發明之利用紅外線之多結晶晶圓的攝影影像之 照片。 圖4B係參考例之利用紅外線之多結晶晶圓的攝影影像之 照片。 圖5係用以實施本發明變化例之多結晶晶圓之檢查方法 的光學系統之側視圖。 圖6係用以實施本發明變化例之多結晶晶圓之檢查方法 的光學糸統之側視圖。 099117151 16 201100788 圖7係用以實施本發明變化例之多結晶晶圓之檢查方法 的光學系統之側視圖。 圖8係多結晶晶圓上之檢查範圍（觀察範圍）之俯視圖。 圖9係用以實施本發明變化例之多結晶晶圓之檢查方法 的光學系統之側視圖。 【主要元件符號說明】 1 多結晶晶圓 ❹ 2 光源 3 紅外線 4 缺陷 6 攝影機 7 光轴 8 透鏡 9 遮光罩 〇 A 檢查方向（多結晶晶圓1之搬運方向） D 既定距離 nl 法線 P1 照射位置 P2 攝影位置 P3 攝影位置 a .傾斜角 099117151 17BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycrystalline wafer in which infrared rays are crystallized into a wafer or the like: - a solar cell is used. [Prior Art], Wanfa. According to the method disclosed in Patent Document 1, an infrared CCD camera, a sputum, a sputum, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, a ray, and a & Generation of photographic images 4:: Shooting: The method disclosed by Γ 2 2 is to use the infrared camera to illuminate the infrared reflection from the surface and the infrared ray from the back from the surface of the polycrystalline wafer and the moon m line. And a comparison of the image data from the surface and the back (4) to detect the fracture defect of the polycrystalline crystal. However, in the case where the detection target is a multi-junction (four) wafer, #using the general 〇-infrared transmission light photography method, the crystal pattern covering the crystal direction, the crystal boundary or the contour thereof is also taken as an image, so In the process of image processing, the identification of crystal patterns and defects will be difficult, and it is prone to false detection or neglect of defects. [Prior Art] [Patent Document] Patent Document 1: Japanese Patent Laid-Open No. 2007-258555 Patent Document 2: Japanese Patent Laid-Open Publication No. Hei No. Hei. No. Hei. No. Hei. Problem) An object of the present invention is to reliably detect defects in a polycrystalline wafer by thinning a crystal pattern covering a crystal orientation, a crystal boundary or a contour thereof of a polycrystalline wafer during photographing. (Means for Solving the Problem) According to the above-described problem, the inventors of the present invention repeatedly irradiated the polycrystalline wafer with infrared rays and observed that the infrared rays were transmitted through the infrared rays. The result is the following insights. That is, when the infrared ray passing through the polycrystalline crystal is directly observed at the irradiation position of the infrared ray, the crystal pattern of the polycrystalline wafer of the photographic image cannot be made light. However, when the irradiation position of the infrared ray and the observation position of the transmitted infrared ray, that is, the imaging position of the camera are separated by an appropriate distance, the crystal pattern of the polycrystalline wafer can be made light and can be made only in the polycrystalline wafer. The brightness of the defect is different from the brightness of other normal parts. The present invention has been completed based on such findings. In order to achieve the above object, the present invention discloses the following. (1) A method for inspecting a polycrystalline wafer, comprising: a step of irradiating infrared rays toward the irradiation position from a light source disposed at an irradiation position on a polycrystalline wafer from an optical axis; and injecting infrared rays from the irradiation position Repeating the refraction and reflection inside the polycrystalline wafer, and ejecting from the photographing position on the polycrystalline wafer at a predetermined distance from the irradiation position toward the surface of the polycrystalline wafer, by 099117151 201100788 a step of photographing a camera for positional photography; and a step of detecting a defect in the polycrystalline wafer based on a difference in the degree of freedom of the defect-free portion and the defective portion on the photographic image obtained by the camera. (2) The method for inspecting a polycrystalline wafer according to (1), wherein the photographing position is set to a surface opposite to the surface of the polycrystalline wafer on which the irradiation position is set. (3) The method for inspecting a polycrystalline wafer according to (1), wherein the photographing position is set to be the same surface of the polycrystalline wafer surface on which the irradiation position is set. (4) The method for inspecting a polycrystalline wafer according to any one of (1) to (3) wherein the light source is a single light source, and an optical axis of the light source is inclined to a surface of the polycrystalline wafer And 〇 can extend from the above-described irradiation position to the above-described photographing position side. (5) The method for inspecting a polycrystalline wafer according to any one of (1) to (3) wherein the light source is a plurality of light sources arranged substantially symmetrically with respect to the photographing position, and the optical axis of each of the light sources The surface of the polycrystalline wafer is inclined at the same inclination angle, and is extendable from the respective irradiation positions to the photographing position side. The method for inspecting a polycrystalline wafer according to any one of (1) to (5) wherein the light source is a linear light source, wherein the camera is a line sensor type camera, and the camera It is used to detect infrared rays concentrated by a cylindrical lens. (7) The method for inspecting a polycrystalline wafer according to any one of (1) to (5) wherein the light source is a ring-shaped light source forming a ring-shaped irradiation region, and the camera is a ring-shaped irradiation region The inner side is an area sensor type camera of the photographing area, and the above-mentioned camera is for detecting the infrared ray which is condensed by the magnifying lens. (Effect of the Invention) According to the inspection method of the polycrystalline wafer of the present invention, the infrared rays incident from the irradiation position to the polycrystalline wafer are repeatedly reflected or refracted in the polycrystalline wafer from the direction of the polycrystalline wafer. The photographing position on the polycrystalline wafer after leaving the irradiation position at a predetermined distance is emitted. By photographing the infrared ray emitted from the photographing position by the camera, it is possible to obtain a photographic image in which the crystal pattern is lightened and the defect is clearly recognized, and the defect can be easily and surely detected. Specifically, when there is no defect in the polycrystalline wafer, since the infrared rays are repeatedly reflected or refracted in the polycrystalline wafer, the intensity of the infrared rays reaching the photographing position is substantially uniform, and is hardly affected by the crystal pattern. , 099117151 6 201100788 Therefore, the photographic image obtained by the camera will be a uniform brightness image that does not reflect the crystal pattern of the polycrystalline wafer. However, when there is a defect in the polycrystalline wafer, the defect will cause the infrared rays to be reflected indiscriminately, and the intensity of the infrared rays reaching the photographing position will become uneven. Therefore, on the photographic image obtained by the camera, the defect will appear as a region having a lower brightness than in the case where there is no defect. Thus, according to the present invention, the photographic image obtained by the camera is substantially unaffected by the crystal pattern covering the crystal orientation, the crystal boundary or the outline of the polycrystalline germanium wafer, since only the luminance of the defect and the non-defective portion is different, Defects in polycrystalline wafers can be reliably detected. [Embodiment] Figs. 1 and 2 show an optical system for carrying out the inspection method of the polycrystalline wafer 1 of the present invention. 1 is a side view showing an optical system in an inspection direction (transport direction of the polycrystalline wafer 1) A from the right to the left state, and FIG. 2 is a front view showing an optical system in which the inspection direction A is from the paper surface toward the paper surface. . An optical system for carrying out the inspection method of the polycrystalline wafer 1 of the present invention will be described with reference to Figs. 1 and 2 . First, a line extending in a direction orthogonal to the conveyance direction A of the polycrystalline wafer 1 is irradiated from the linear light source 2 disposed on the lower surface side of the polycrystalline wafer 1 toward the linear irradiation position P1 of the polycrystalline wafer 1. Infrared infrared 3. At this time, the light source 2 is disposed such that the optical axis of the light source 2 passing through the irradiation position P1 is inclined with respect to the normal line n1 of the surface of the polycrystalline wafer 1. Specifically, the optical axis 2 of 099117151 7 201100788 forms an inclination angle α with respect to the normal line n1 so that the infrared ray 3 emitted from the light source 2 extends from the irradiation position Ρ1 side to the photographic position Ρ2 side. Such a linear light source 2 can be constructed by linearly arranging a plurality of infrared light-emitting diodes or by combining a rod-shaped infrared light source and a light source cover forming a linear slit. As schematically shown in FIG. 3, the infrared rays 3 incident from the irradiation position Ρ1 are repeatedly reflected and refracted inside the polycrystalline wafer 1, and are repeatedly reflected on the front and back surfaces of the polycrystalline wafer 1 to reach the photographing position. Ρ 2. The infrared ray 3 which reaches the photographing position is partially reflected, and a part is directly emitted from the surface of the multi-crystal wafer 1. Among them, the infrared ray 3 emitted from the photographing position Ρ2 is arranged by the camera 6 of the photographing position 利用2 by the optical axis 7, and the photographed image is obtained by the camera 6. Here, the photographing position Ρ2 is set at a position away from the irradiation position Ρ1 by a predetermined distance D in the plane direction of the polycrystalline wafer 1. In the present embodiment, the camera 6 is disposed on the opposite side of the light source 2 with respect to the polycrystalline wafer 1. Further, the optical axis 7 of the camera 6 passes through the photographing position Ρ2, and is perpendicular to the surface of the polycrystalline wafer 1. The wavelength of the infrared ray 3 which is linearly irradiated is preferably a wavelength suitable for detecting an internal defect, for example, a wavelength region of 0.7 #m to 2.5 // m. In addition, the camera 6 preferably also has good sensitivity in this wavelength region. The photographing position P2 is set at a position away from the irradiation position P1 by a predetermined distance D. The distance D can be set in accordance with the crystal structure of the polycrystalline wafer 1 or its thickness of 099117151 8 201100788, etc., and can be set at the optimum position where the crystal pattern becomes light. Further, the inspection method of the present invention is preferably applied to a plurality of crystallized wafers 1 having a thickness of 0.1 to 0.25 mm. The reason for this is that as the thickness of the polycrystalline wafer 1 is thicker, the infrared ray 3 is refracted and absorbed inside the polycrystalline wafer 1 and absorbed, which causes the intensity of the infrared ray 3 photographed by the camera 6 to be lowered, and it is impossible to obtain a clear photograph. image. When the thickness of the polycrystalline wafer 1 is thinned, the number of times of refraction or reflection occurring when the infrared ray 3 reaches the photographing position P2 will be small, and the photographic image obtained by the camera 6 will remain in a crystal pattern. Further, the optical axis of the light source 2 is preferably set at 20 to the inclination angle α of the normal line n1 of the surface of the polycrystalline wafer 1. Above 40. The following range. The reason for this is that the inclination angle α is less than 20. At the time of the infrared ray 3, the number of times of refraction and reflection required to reach the photographing position p2 after leaving the predetermined distance D from the irradiation position ρ is increased, and the intensity of the infrared ray 3 photographed by the camera 6 is lowered, and a clear photographic image cannot be obtained. The tilting angle α is greater than 2G. When the infrared ray is reduced, the refraction required for the position P2 is reduced. The number of reflections will be reduced to ~ The image will remain in the crystal pattern. The second: the step, the illumination position ρι and the photographic position? 2 between the established distance 取 take a sigh at 1~3mm. When the predetermined distance D is shorter than lrnm, the refraction required for the infrared to reach the photographing position P2, the number of reflections will be less, and the crystal form will remain. When the predetermined impurity D is longer than the 3 coffee, the number of times of folding and reflection becomes large. The intensity of the infrared light 3 photographed by the camera 6 is lowered, and a remarkable photographic image cannot be obtained. 099117151 9 201100788 In the inspection method 10 of the polycrystalline wafer 1 of the present invention, in order to make the influence of the crystal pattern small and to obtain a visible photographic image, the thickness of the polycrystalline wafer 1 is appropriately set in the above-mentioned range. , the inclination angle α, the predetermined distance p. In the optical system for performing the inspection method of the polycrystalline wafer crucible configured as described above, the infrared ray 3 which passes through the non-defective defect-free region of the polycrystalline wafer 1 is crystallization of a plurality of randomly existing crystal grains. The direction or the boundary of the crystal is repeatedly refracted or reflected to reach the photographing position Ρ2. Repeating a plurality of random refracted or reflected infrared rays 3, the refraction of each crystal grain upon reaching the photographing position P2 after leaving the irradiation position ρ1 for a predetermined distance D. The influence of the reflections will cancel each other, so that the camera 6 is photographed at the photographing position p2. The photographic image there will become a linear photographic image with uniform brightness. On the other hand, when the polycrystalline wafer 1 has the defect 4, the infrared ray 3 will be randomly reflected or absorbed in the defect 4, and thus the photographic image photographed at the photographing position P2 may appear due to the above. The shadow or bright part caused by defect 4. Since the shadow or bright portion caused by the defect 4 has a different brightness from the photographic image formed by the infrared ray 3 passing through the defect-free region, the defect 4 can be detected by comparing the luminances of both. The multi-crystal wafer crucible is transported in the transport direction A, and the above steps are repeated continuously to obtain a photographic image having an area as shown in Fig. 4A. 4A and 4B show a photographic image of the camera 6 that images the infrared ray 3 that has passed through the region containing the defect 4. In Fig. 4A, a background image of the uniform sound of the infrared rays 3 passing through the defect-free region 399117151 201100788 is formed, and a bright image which is darker shaded by the infrared rays 3 passing through the defect 4 is formed. Therefore, the defect 4 can be easily and surely recognized by detecting a region having a different luminance from the background image of the uniform luminance. Further, Fig. 4A shows a polycrystalline wafer 1 having a thickness of 0.2 mm as a defect detection target at a predetermined distance D = 2 mm and an inclination angle α = 20. The photographic image obtained under the set conditions. Further, in the present invention, the photographing position Ρ2 is set at a position away from the irradiation position Ρ1 by a predetermined distance D = 2 mm in the plane direction of the polycrystalline wafer Ο 1 . Different from this, when the photographing position is set at the position p3 where the predetermined distance D of the optical axis extension line of the light source 2 is shorter than 1 mm (refer to FIG. 1), it can be photographed at the photographing position P3 and is not sufficiently repeated. The infrared rays 3 emitted by refraction or reflection, so the photographic image will be an image affected by the crystal boundary. Therefore, even if a photographic image is formed from the infrared ray 3 passing through the region containing the defect 4, as shown in Fig. 4B, the portion affected by the defect 4 is buried in the crystal pattern, and the recognition of the defect 4 and the crystal pattern is changed. difficult. 5 is a view in which the two linear light sources 2 are disposed on the lower side of the polycrystalline wafer 1 at a position where the line normal to the photographing position P2 (the optical axis 7 of the camera 6) is disposed in line symmetry from the respective light sources 2 toward the polycrystalline crystal. The irradiation position P1 at two positions in the circle 1 illuminates the linear infrared rays 3 in different oblique directions. In addition, in this example, the inclination angle formed by the optical axis of each light source 2 and the face of the polycrystalline wafer is set to be substantially the same. According to this example, in addition to the above effects, the infrared light 3 can be detected by the camera 6. Since the amount of light is increased, a bright photographic image can be obtained, so the defect 4 can be easily detected by 099117151 201100788. Further, Fig. 6 uses a cylindrical lens 8 to condense the infrared rays 3 that have passed through the polycrystalline crystal circle 1, and detects the condensed infrared rays 3 by a line sensor type camera 6. In this example, the cylindrical lens 8 is arranged such that its longitudinal direction is along the linear infrared rays 3, and the imaging of the infrared rays 3 is enlarged in the conveyance direction of the polycrystalline wafer 1. As described above, when the infrared ray 3 is amplified by the lens 8, the infrared ray 3 can be easily detected by the camera 6, and the erroneous detection or negligence can be reduced for the continuous movement of the polycrystalline wafer 1, which is advantageous. In other words, the lens 8 can also be as shown in Figs. 1 and 2 and incorporated into a single light source 2. Further, the specific size or arrangement of the optical system or the like can be set to an appropriate value in accordance with the thickness of the polycrystalline wafer 1, the wavelength region of the infrared ray 3, the irradiation angle of the infrared ray 3, the sensitivity of the camera 6, and the like. Next, Fig. 7 shows that the light source 2 is a ring type light source, the camera 6 is a zone type camera, and the light source 2 and the camera 6 are disposed on the side opposite to the polycrystalline crystal 1. The ring type light source 2 is concentrically arranged with respect to the optical axis 7 of the camera 6. The irradiation position P1 of the light source 2 is set at a position where the light beam of the light source 2 illuminating the infrared ray 3 appears to be the largest, which is a circle smaller than the circular shape of the light source 2. According to the present example, the photographing position (photographing area) P2 is the detection range of the area type camera 6, which is offset from the irradiation position P1 toward the optical axis 7 of the camera 6 by the distance D inside the ring type light source 2 as shown in FIG. The circle with a smaller radius is 099117151 12 201100788 inside. In addition, the magnifying convex lens of the objective lens side of the camera 6 can be placed. In addition, the 仏m仏 ‘, 、, and 1 may be formed by a ring-shaped slit. What? The column 'infrared rays 3 from the light source 2 will enter the inside of the two crystals (4) 1 from the circular irradiation position, and will reach the inside of the circular photographing position Ρ2 of the camera 6 after repeated refraction and reflection, and the area type camera 6 Into the light photography. The %-type light source 2 irradiates the infrared rays 3 from the entire direction of the camera 6 toward the irradiation position P1 of the polycrystalline wafer, so that even if the defect 4 in the polycrystalline wafer i is not easily detected from a certain direction, the defect can be * The inspection, J, and & area & area type camera 6 can be used to set the inspection _ (observation range) of the polycrystalline wafer 1 to a larger extent than the linear inspection range. Improve inspection efficiency. Further, Fig. 9 shows an example in which the ring type light source 2 and the area type camera 6 are disposed on the same surface side of the polycrystalline crystal® 1. In this example, the infrared ray line 3 from the light source 2 also enters the inside of the polycrystalline wafer κ from the circular irradiation position ρ, and after repeated refraction and reflection, reaches the inside of the circular photographing position p2, and is composed of the area type. The camera 6 performs photography. Further, when the infrared ray 3 is reflected on the surface of the polycrystalline wafer crucible to make the photographic image inconspicuous, the visor 9 for shielding light can be provided in the camera 6 to prevent the reflected light of the infrared ray 3 from directly entering the camera 6. Further, in this example, the slit position of the ring type can be used to form the irradiation position P1. According to FIG. 9, the 'irradiation position P1 and the photographing position P2 are on the same plane for the polycrystalline crystal 099117151 13 201100788 circle 1, so that the portion of the defect 4 in the polycrystalline wafer 1 is stronger than the other normal portion to the infrared 3 When the reflection characteristic is used, the defect 4 can be detected efficiently and easily. Further, even when the irradiation position P1 or the photographing position P2 cannot be set in the state of one surface of the polycrystalline wafer 1, the defect 4 can be detected. Of course, in the above-described FIGS. 1, 2, 5, and 6 examples, the linear light source 2 may be disposed on the same side of the multi-crystal wafer 1 as the camera 6. Further, the infrared ray 3 from the linear light source 2 may be a light guide body such as an optical fiber or an acrylic resin plate as shown in the ninth chain line of FIG. 9, and four end faces (four sides) of the polycrystalline wafer 1 may be used. At least one of the end faces is irradiated toward the inside of the polycrystalline wafer 1. In this case, according to FIGS. 5, 6, 7, and 9, in the movement of the polycrystalline wafer 1, even the front end edge portion of the traveling direction of the polycrystalline wafer 1 or the rear end portion of the traveling direction The edge portion is partially detached from one of the light sources 2 or the light source 2, and if the other light source 2 or other portion of the light source 2 is not detached from the edge portion of the moving polycrystalline wafer 1, the defect 4 can be continuously detected. Therefore, the defect 4 can be detected for the edge portion of the polycrystalline wafer 1. In the above example, the infrared ray 3 is irradiated toward the irradiation position P1 of the polycrystalline wafer 1 in the oblique direction. Therefore, in the process of the infrared ray 3 passing through the polycrystalline wafer 1, there are more opportunities for refraction and reflection than in the vertical direction, and the infrared ray 3 is more difficult to be affected by the crystal pattern. However, the irradiation direction of the infrared rays 099117151 14 201100788 may be set to be substantially perpendicular to the irradiation position P1 of the polycrystalline wafer. Even if the infrared ray 3 is reflected at a plurality of crystal boundaries, the infrared ray 3 is diffused in a direction other than the vertical direction. Therefore, by capturing the infrared ray 3 of the expansion, a photographic image which is not affected by the crystal pattern can be obtained. In the above example, the infrared ray 3 is irradiated in a state of being inclined toward the irradiation position P1 of the polycrystalline wafer 1 and directed to the imaging position p2. Therefore, most of the infrared rays 3 pass through the polycrystalline wafer 1 toward the photographing position P2, so that the necessary amount of light can be secured at the photographing position P2. However, even if the infrared ray 3 passes through the polycrystalline wafer 1 in a direction other than the photographing position p2, the amount of photographic light is generated at the photographing position P2 due to the refraction, reflection, and disorder reflection inside the polycrystalline wafer 1, and therefore, in principle, The inspection of defect 4 can be performed. When the polycrystalline wafer 1 is stopped at the inspection position, the photographing conditions can be made good. On the other hand, when the shutter speed is prioritized, the polycrystalline crystal circle 1 can be continuously moved. Further, the posture of the polycrystalline wafer 1 may not be horizontal, and may be set to a vertical or inclined state in accordance with the inspection space. Further, the present invention is not limited to germanium wafers, and may be used in wafers of other polycrystalline structures. The present invention has been described in detail with reference to the preferred embodiments of the present invention. It is to be understood by those of ordinary skill in the art that various changes or modifications can be made without departing from the spirit and scope of the invention. This application is based on the Japanese patent application filed on May 29, 2009 (specially 099117151 15 201100788 willing to be 2009-130725) and the Japanese patent application (Japanese Patent Application 2009-186304) filed on August 11, 2009. The content has been taken here for reference. (Industrial Applicability) According to the inspection method of the polycrystalline wafer of the present invention, it is possible to obtain a photograph in which the crystal pattern covering the crystal orientation, the crystal boundary or the outline of the polycrystalline wafer is lightened and the defect is clearly recognized. Image and easy and reliable detection of defects. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view of an optical system for carrying out the inspection method of the polycrystalline wafer of the present invention. Fig. 2 is a front elevational view of an optical system for carrying out the inspection method of the polycrystalline wafer of the present invention. Figure 3 is an illustration of the infrared reflection and refraction conditions inside a polycrystalline wafer. Fig. 4A is a photograph of a photographic image of a polycrystalline wafer using infrared rays of the present invention. Fig. 4B is a photograph of a photographic image of a polycrystalline wafer using infrared rays of a reference example. Fig. 5 is a side view of an optical system for carrying out a method of inspecting a polycrystalline wafer according to a variation of the present invention. Fig. 6 is a side view of an optical system for carrying out an inspection method of a polycrystalline wafer according to a modification of the present invention. 099117151 16 201100788 Figure 7 is a side view of an optical system for carrying out an inspection method for a polycrystalline wafer according to a variation of the present invention. Fig. 8 is a plan view showing an inspection range (observation range) on a polycrystalline wafer. Fig. 9 is a side view of an optical system for carrying out an inspection method of a polycrystalline wafer according to a modification of the present invention. [Main component symbol description] 1 Multi-crystal wafer ❹ 2 Light source 3 Infrared 4 Defect 6 Camera 7 Optical axis 8 Lens 9 Hood 〇 A Inspection direction (transport direction of polycrystalline wafer 1) D Established distance nl Normal line P1 Irradiation Position P2 Photography position P3 Photography position a. Tilt angle 099117151 17