[223061 玖、發明說明 · 【發明所屬之技術領域】 本發明有關於灰階罩幕或包含微細圖案之光罩之缺陷檢 查方法及缺陷檢查裝置等。 【先前技術】 近年來，在大型LCD用罩幕之領域中，試著減少使用灰 階罩幕之罩幕之數目（月刊FPD Intelligence，1 99 9年5月）。 在此處之灰階罩幕如圖9(1)所示，在透明基板上具有遮 光部1，透過部2，和灰階部3。灰階部3是例如使灰階罩 幕用來形成大型LCD用曝光機之解像限度以下之遮光圖 案3a之區域，其形成目的是減小透過該區域之光之透過 量，用來減小該區域之照射量，藉以選擇性的變化光阻之 膜厚。3 b是灰階部3之曝光機之解像界限以下之微細透過 部。遮光部1和遮光圖案3 a通常均由鉻或鉻化物等之相同 材料構成，由相同厚度之膜形成。透過部2和微細透過部 3b均是在透明基板上未形成有遮光膜等之透明基板之部 份。 使用灰階罩幕之大型LCD用曝光機之解像界限’在分節 方式之曝光機爲大約3 // m，在鏡投影方式之曝光機爲大約 4//m。因此，在圖9(1)之灰階部3中使透過部3b之空白 幅度成爲3 // m以下，使曝光機之解像界限以下之遮光圖 案3a之線幅成爲3/zm以下。在使用上述之大型LCD用曝 光機進行曝光之情況時，因爲通過灰階部3之曝光之光’ 會變成全體之曝光量不足’所以經由該灰階部3曝光之正 5 312/發明說明書(補件)/92-06/92108791 1223061 型光阻，會使膜厚變薄的殘留在基板上。亦即，抗蝕劑由 於曝光量之不同’在與通常之遮光部1對應之部份和與灰 階部3對應之部份，對顯像液之溶解性可以產生差異，所 以顯像後之抗蝕劑之形狀如圖9 (2 )所示，在與通常之遮光 部1對應之部份Γ例如成爲大約1.3 // m，在與灰階部3對 應之部份3 ’例如成爲大約〇. 3 # m，在與透過部2對應之部 份成爲沒有抗蝕劑之部份2 ’。然後，在沒有抗蝕劑之部份 2 ’進行被加工基板之第1蝕刻，利用灰化等除去與灰階部 3對應之薄部份3 ’之抗蝕劑，在該部份進行第2蝕刻，以 1片之罩幕進行習知之2片罩幕部份之步驟，因此可以減 少罩幕之片數。 習知之由遮光部和透過部構成之罩幕之檢查方法，例如 是比較檢查方法，使用2個之光學系用來使罩幕圖型間進 行比較。下面將具體的說明該方法。 圖10(1)表示在遮光部1產生白缺陷11(針孔），在透過部 產生黑缺陷1 2 (點）之狀態，箭頭表示比較檢查裝置之一方 之透鏡（以下稱爲上透鏡）之掃描方式。 圖1 〇 (2)表示沿著上述透鏡之掃描線所獲得之透過率信 號1 3。透過率信號1 3，例如利用被配置在各個透鏡單位內 之CCD線感測器進行檢測。透過率信號1 3之位準分別設 定爲遮光部1爲B，透過部2爲W，遮光部1之透過率爲 0%，透過部2之透過率爲100%。透過率信號13基本上由 在圖案之邊緣（遮光部和透過部之境界）產生之圖案邊緣線 信號（圖案形狀信號）構成，在產生有缺陷之情況時，出現 6 312/發明說明書(補件)/9106/92108791 1223061 在遮光部1產生之白缺陷信號1 1 ’，和在透過部2產生之 黑缺陷信號1 2 ’。 圖10(3)表示在未產生有與圖10(1)相同之圖案之缺陷之 情況時’以另外一*方之透鏡（以下稱爲下透鏡）所獲得之透 過率信號1 3 ’。 圖10(4)是對各個透鏡所獲得之透過率信號進行減算（差 分）所求得之差信號14。亦即，從圖10(2)之透過率信號13 中減去圖10(3)之透過率信號13’所求得之差信號。在差信 號1 4，從各個透鏡之透過率信號除去圖案邊緣線信號，只 抽出圖案缺陷信號1 Γ、1 2 ’。 圖10(5)表示在只抽出圖案缺陷信號之差信號14，設定 抽出遮光部1和透過部2所需要之臨限値，以正側之臨限 値15a檢測白缺陷，以負側之臨限値15b檢測黑缺陷。假 如臨限値變低時檢測敏感度就上升，但是需要設定在未檢 測到疑似缺陷之位準。 爲著要看淸在那一方之透鏡產生那一種缺陷，例如， 在上透鏡之電路，與下透鏡之信號進行比較（從上透鏡之信 號減去下透鏡之信號），在上透鏡之遮光部1產生有白缺陷 之情況時，就在正側輸出缺陷信號，在上透鏡之透過部2 產生黑缺陷之情況時，就在負側輸出缺陷信號，依照此種 方式檢測上透鏡之白缺陷和黑缺陷（上述之圖10(2)〜 (5))。同樣的，例如在下透鏡之電路，與上透鏡之信號進 行比較（從下透鏡之信號中減去上透鏡之信號），當在下透 鏡之遮光部1產生有白缺陷之情況時，就在正側輸出缺陷 7 312/發明說明書(補件)/92-06/92108791 1223061 信號，當在下透鏡之透過部2產生有黑缺陷之情況時，就 在負側輸出缺陷信號，依照此種方式檢測下透鏡之白缺陷 和黑缺陷。 【發明內容】 (發明所欲解決之問題） 上述之習知之比較檢查方法用來檢查只由遮光部和透過 部構成之習知之罩幕，所以不適於用來檢查具有灰階部之 灰階罩幕。 詳細而言，習知之比較檢查方法在檢查灰階罩幕時，會 有下面所述之問題。 亦即，灰階部之缺陷信號由於缺陷本身之微小而變弱， 在使用習知之比較檢查裝置之情況時，假如不使其臨限値 低於通常之遮光部之檢查所使用之臨限値，則檢測會有困 難。但是，例如在灰階部是使用灰階罩幕形成曝光機之解 像界限以下之微細圖案之區域之情況時，與該微細圖案對 應的，如圖1 1所示，在灰階部產生特有之基準信號位準（雜 訊帶）1 6。在比較檢查時，對各個透鏡所求得之透過率進行 減算（差分），用來求得差信號，只抽出圖案缺陷信號，但 是在灰階部之微細遮光圖案間，於產生有稍微之圖案偏移 之情況時，基準信號位準被放大（最大2倍），本來不是缺 陷者會被檢測爲缺陷（疑似缺陷），因此不能使臨限値下 降，不能進行高敏感度之檢查爲其問題。 另外，習知之比較檢查因爲是檢查白缺陷或黑缺陷，所 以在灰階罩幕中之最重要因素之透過率，要進行保證會有 8 312/發明說明書(補件)/92-06/92108791 1223061 困難。亦即，例如在遮罩全體區域，在灰階部之遮 線幅對設計尺寸成爲不足（線幅大）或過大（線幅小） 透過率之容許値之情況時，或是構成灰階部之半透 透過率超過容許値之情況時，因爲在比較檢查對各 所獲得之透過率信號進行減算，用來求得差信號， 會出現差，會有不能檢測此種透過率缺陷之問題。 在灰階部沒有形狀缺陷之情況時此問題特別嚴重。 在灰階部其透過率假如在容許範圍時，必需要不會 缺陷，但是在習知之比較檢查時，因爲檢測爲形狀 所以習知之檢查所檢測到者，會成爲透過率在容許 其結果是本來不會檢測爲缺陷者會被檢測出，因此 查之正確性（能力）之問題。 另外，同樣之問題亦會發生在例如TFT通道部形 罩幕等之具有微細圖案之光罩，或具有線幅爲3 // 之線和空白之微細而且高精確度圖案之光罩。例如， 通道形成用光罩，隨著TFT通道部之微細化，會有 急激微細化之傾向。對於此種圖案，在使用習知之 行檢查之情況時，由於檢查機之載物台之振動或上 之圖像偏移，會產生疑似缺陷，產生其他之微細圖 有之疑似缺陷，當敏感度落到不能檢測疑似缺陷 時，不能獲得能夠保證檢測出缺陷之位準之敏感度 題。 爲著解決此種問題，本申請人先前申請有檢測方 稱爲單眼透過率檢查），不是利用比較進行檢查，對 312/發明說明書(補件)/92-06/92108791 光圖之 ，超過 過膜之 個透鏡 所以不 特別是 另外， 檢測爲 缺陷， 範圍。 會有檢 成用光 m以下 在丁 FT 使圖案 方法進 下透鏡 案所特 之位準 爲其問 δ (以下 於掃描 9 1223061 罩幕內之圖案所獲得之透過率信號，使用預設之透過率缺 陷之臨限値，用來檢測缺陷（日本國專利案特願 200卜244071 號）。 下面將說明該方法之具體例。 圖1 2 (1)表示遮光部1、透過部2、和灰階部3、5之任何 一個均未產生缺陷之情況，箭頭表示檢查裝置之透鏡之掃 描方向（檢查方向）。 圖12(2)表示沿著上述之掃描方向所獲得之透過率信號 7。透過率信號在遮光部1爲透過率〇%，在透過部2爲透 過率1 0 0 %，在灰階部3、5爲透過率5 0 %。 在此處如圖12(2)所示，例如設置灰階部之透過率缺陷之 臨限値（上限側8a、下限側8b)，當超過該等之臨限値之情 況時，就判斷爲在灰階部發生有透過率缺陷。 在此種情況，如圖12(2)所示，更設有通常之遮光部和透 過部之透過率缺陷之臨限値（透過部側9a、遮光部側9b)， 在超過該等之臨限値之情況時，就判斷爲在遮光部或透過 部發生有透過率缺陷，最好可以同時檢測遮光部之遮光性 之降低缺陷，和透過部之透過性之降低缺陷等之半透過性 之透過率缺陷。 另外在此種情況，使用由灰階部用之透過率缺陷抽出臨 限値8 a、8b和通常之遮光部和透過部之透過率缺陷抽出臨 限値9a、9b所形成之透過率缺陷區域10a、10b，可以與檢 查區域無關的檢測透過率缺陷。亦即，假如進入該透過率 缺陷區域1 0a、1 Ob時，可以與檢查區域無關的判斷爲有透 10 312/發明說明書(補件)/92-06/92108791 1223061 過率缺陷。 依照上述之檢查法時，可以進行透過率本身之直接檢 查，因此，可以進行保證具有灰階部之透過率。 另外，因爲是不進行圖案辨識之檢查方法，所以可以避 免微細圖案檢查時之特有之圖案形狀所引起之發生疑似缺 陷之問題（臨限値不能降低之問題），因此，臨限値可以下 降，可以獲得能夠滿足包含有灰階罩幕或微細圖案之光罩 之要求精確度（規格）之敏感度。 另外，因爲不是根據圖案之比較，使用圖案缺陷信號， 而是使用對透過率信號預設之透過率缺陷抽出臨限値，所 以可以避免比較檢查時之獲得透過率信號間之差信號成爲 問題之微細圖案所特有之基準信號位準之放大之問題（臨 限値不能降低之問題），因此，臨限値可以降低，可以獲得 能夠滿足包含灰階罩幕或微細圖案之光罩之要求精確度之 敏感度。 另外，因爲不需要比較對象物，所以可以利用單眼檢查。 另外’經由變更灰階部用之透過率缺陷抽出臨限値，可以 保證具有符合使用者所使用之灰階罩幕之曝光條件之透過 率。 但是，在使用上述之方法，依照箭頭方向掃描由圖1 (1) 之微細圖案構成之灰階部之透過率藉以測定之情況時，本 來微細圖案區域之透過率爲均一，例如5 0 %，在圖1 (2)所 示之沿著微細圖案之形狀之透過率進行變動之情況，當發 生此種變動時，會造成超過灰階部之透過率缺陷之臨限値 11 312/發明說明書(補件)/92-06/92108791 1223061 (上限側8a、下限側8b)，檢測到透過率之疑似缺 會有實質上不能進行透過率缺陷之檢測之問題。 所獲得之灰階部之透過率特性，和實際使用灰階 轉印基板之抗蝕劑上獲得轉印圖案時之灰階部之 性，會發生由於轉印所使用之曝光裝置之光學條 條件而不同之情況。因此，轉印所使用之曝光裝 條件應該使灰階部成爲均一之透過率（例如5 0 %) 考慮檢查裝置之透過率信號不是如此之情況。另 之問題亦發生在例如TFT通道部形成用光罩等之 圖案之光罩，或具有線幅爲3 // m以下之線和空 而且高精確度之圖案之光罩。 本發明用來解決上述之問題，其目的是提供缺 法和缺陷檢查裝置，如圖1 (2)所示的使沿著微細 狀之透過率進行變動，在檢測到有透過率信號之 之位置，可以檢查成不會檢測該位置成爲疑似缺 另外，使用上述之單獨之透過率信號和其透過 出臨限値，進行透過率本身之直接檢查，在此種 率檢查中，因爲是不進行圖案辨認之檢查方法， 行遮光部和透過部之形狀缺陷（白缺陷、黑缺陷） 有困難。因此，要進行具有遮光部、透光部，和 灰階罩幕之高精確度檢查時，需要進行包含圖案 較檢查和不包含圖案辨識之透過率檢查之雙方， 很多檢查時間之問題。同樣之問題亦發生在例如 部形成用光罩等之具有微細圖案之光罩，和具有 312/發明說明書(補件)/92-06/92108791 陷，所以 檢查裝置 罩幕在被 透過率特 件之設定 置之設定 ，但是需 外，同樣 具有微細 白之微細 陷檢查方 圖案之形 疑似缺陷 陷。 率缺陷抽 單眼透過 所以要進 之檢查會 灰階部之 辨識之比 會有需要 TFT通道 線幅爲3 12 1223061 # m以下之線和空白之微細而且高精確度之圖案之光罩。 本發明用來解決上述之問題，其目的是提供缺陷檢查方 法和缺陷檢查裝置，在具有遮光部、透過部，和灰階部之 灰階罩幕中，可以以短時間和高精確度進行缺陷檢查。 (解決問題之手段） 本發明具有以下之構成。 (構成1)一種灰階罩幕之缺陷檢查方法，用來檢查灰階罩幕 之灰階部，該灰階罩幕具有：遮光部；透過部；和灰階部， 其目的是在調整透過量後之區域，使透過該區域之光之透 過量減小，用來選擇性的變化光阻之膜厚；上述之灰階部 由形成有使用該灰階罩幕之曝光機之解像界限以下之遮光 圖案之區域構成；該缺陷檢查方法之特徵是所具備之步驟 包含有： 掃描上述之灰階部，用來獲得透過率信號； 對上述之透過率信號施加修正處理，使其近似上述灰階 罩幕之使用時之灰階部之透過率特性；和 當上述之修正處理後之透過率信號超過預設之灰階部之 透過率缺陷之臨限値之情況時，就判斷爲在灰階部產生有 缺陷。 (構成2)—種灰階罩幕之缺陷檢查方法，用來檢查灰階罩幕 之灰階部，該灰階罩幕具有：遮光部；透過度；和灰階部， 其目的是在調整透過量後之區域，使透過該區域之光之透 過量減小，用來選擇性的變化光阻之膜厚，上述之灰階部 由形成有使用該灰階罩幕之曝光機之解像界限以下之遮光 13 312/發明說明書(補件)/92-06/92108791 1223061 圖案之區域構成；.該缺陷檢查方法之特徵是所具備之步驟 包含有： 掃描上述之灰階部，用來獲得透過率信號； 在上述之透過率信號具有週期性之變動之情況時’施加 模糊處理用來使該信號平坦化；和 當上述之模糊處理後之透過率信號超過預設之灰階部之 透過率缺陷之臨限値之情況時，就判斷爲在灰階部產生有 缺陷。 (構成3)—種光罩之缺陷檢查方法，用來檢查光罩之微細圖 案部，該光罩具有遮光部、透過部，和微細圖案部’該缺 陷檢查方法之特徵是所包含之步驟有： 掃描上述之微細圖案部，用來獲得透過率信號； 在上述之透過率信號具有週期性變動之情況時，施加模 糊處理，用來使該信號平坦化；和 當上述之模糊處理後之透過率信號超過預設之微細圖案 部之透過率之臨限値之情況時，就判斷爲在微細圖案部產 生有缺陷。 (構成4)在構成3之光罩之缺陷檢查方法，其中上述之微細 圖案部是使透過率信號週期性的變動，當超過預設之微細 圖案部之透過率缺陷之臨限値時，就檢測爲透過率之疑似 缺陷。 (構成5) —種缺陷檢查裝置，用來檢查灰階罩幕，該灰階罩 幕具有：遮光部；透過部；和灰階部，其目的是在調整透過 量後之區域，使透過該區域之光之透過量減小，用來選擇 14 312/發明說明書(補件)/92-06/92108791 1223061 性的變化光阻之膜厚；該缺陷檢查裝置之特徵是具有： 檢測裝置，利用平行光源和受光透鏡掃描形成在罩幕內 之圖案，用來檢測透過率信號； 施加修正處理裝置，對上述之透過率信號施加修正處 理，使其近似上述灰階罩幕之使用時之灰階部之透過率特 性（例如在上述之透過率信號週期性變動之情況時，施加模 糊處理使該信號平坦化）； 設定裝置，對於上述之透過率信號，至少設定灰階部之 透過率缺陷之臨限値；和 判斷裝置，在超過上述之臨限値時，判斷爲在灰階部產 生有透過率缺陷。 (構成6)—種缺陷檢查裝置，用來檢查光罩，該光罩具有遮 光部、透過部，和通常檢查困難之微細圖案部，該缺陷檢 查裝置之特徵是具有： 檢測裝置·，利用平行光源和受光透鏡掃描形成在罩幕內 之圖案，用來檢測透過率信號； 施加修正處理裝置，對上述之透過率信號施加修正處 理，使其近似上述灰階罩幕之使用時之灰階部之透過率特 性（例如在上述之透過率信號週期性變動之情況時，施加模 糊處理使該信號平坦化）； 設定裝置，對於上述之透過率信號，至少設定微細圖案 部之透過率之臨限値；和 判斷裝置，在超過上述之臨限値時，判斷爲在微細圖案 部產生有缺陷。 15 312/發明說明書(補件)/92-06/92108791 1223061 (構成7)—種灰階罩幕之製造方法，其特徵是具有缺陷檢查 步驟，使用構成1或2之方法進行缺陷檢查。 (構成8)—種光罩之製造方法，其特徵是具有缺陷檢查步 驟，使用構成3或4方法進行缺陷檢查。 另外，本發明亦具有以下之構造。 (構成1) 一種灰階罩幕之缺陷檢查方法，用來檢查灰階罩 幕，該灰階罩幕具有：遮光部；透過部；和灰階部，其目的 是在調整透過量後之區域’使透過該區域之光之透過量減 小，用來選擇性的變化光阻之膜厚；該缺陷檢查方法之特 徵是所包含之步驟有·· 對於至少形成有遮光部和透過部之區域，使用掃描罩幕 內之圖案所獲得之透過率信號，根據圖案之比較’使用對 圖案缺陷信號預設之圖案缺陷之臨限値檢測缺陷’利用比 較檢查法檢測缺陷；和 至少對灰階部，使用掃描罩幕內之圖案所獲得之透率信 號之預設透過率缺陷之臨限値’利用檢測缺陷之方法用來 檢測缺陷。 (構成2)在構成1之灰階罩幕之缺陷檢查方法’其中上述之 灰階部由使用灰階罩幕用以形成曝光機之解像界限以下之 遮光圖案之區域構成。 (構成3)一種光罩之缺陷檢查方法，用來檢查具有遮光部， 透過部、和微細圖案部之光罩’其特徵是所包含之步驟有： 對於至少形成有遮光部和透過部之區域’使用掃描罩幕 內之圖案所獲得之透過率信號’根據圖案之比較’使用對 16 312/發明說明書(補件)/92_〇6/92應791 1223061 圖案缺陷信號預設之圖案缺陷之臨限値檢測缺陷，利用比 較檢查法檢測缺陷；和 至少對微細圖案部，使用掃描罩幕內之圖案所獲得之透 過率信號之預設透過率缺陷之臨限値，利用檢測缺陷之方 法用來檢測缺陷。 (構成4)在構成3之光罩之缺陷檢查方法，其中上述之微細 圖案部是比較檢查困難之微細圖案。 (構成5)在構成1至4之任一項之光罩之缺陷檢查方法，其 中上述之灰階部之檢查是當多個之透過率檢測裝置用來獲 得掃描罩幕內之圖案所獲得之透過率信號之情況時，就分 別獨立的進行檢查。 (構成6)—種缺陷檢查裝置，用來檢查灰階罩幕，該灰階罩 幕具有：遮光部；透過部；和灰階部，其目的是在調整透過 量後之區域，使透過該區域之光之透過量減小，用來選擇 性的變化光阻之膜厚；該缺陷檢查裝置之特徵是具有： 檢測裝置，用來掃描形成在罩幕內之圖案，藉以檢測透 過率信號； 識別裝置，用來識別是遮光部，透過部和灰階部之那一 個區域； 檢測裝置，對於至少形成有遮光部和透過部之區域，使 用掃描上述罩幕內之圖案所獲得之透過率信號，根據圖案 之比較，使用對圖案缺陷信號預設之圖案缺陷之臨限値檢 測缺陷，利用比較檢查法檢測缺陷；和 檢測裝置，至少對灰階部，使用掃描上述罩幕內之圖案 17 312/發明說明書(補件)/92-06/92108791 1223061 所獲得之透過率信號之預設透過率缺陷之臨限値，利用檢 測缺陷之方法用來檢測缺陷。 (構成7)—種光罩之缺陷檢查裝置，該光罩具有遮光部、透 過部，和微細圖案部，該缺陷檢查裝置之特徵是具有： 檢測裝置，用來掃描形成在罩幕內之圖案，藉以檢測透 過率信號； 識別裝置，用來識別是遮光部，透過部和微細圖案部之 那一個區域； 檢測裝置，對於至少形成有遮光部和透過部之區域，使 用掃描上述罩幕內之圖案所獲得之透過率信號，根據圖案 之比較，使用對圖案缺陷信號預設之圖案缺陷之臨限値檢 測缺陷，利用比較檢查法檢測缺陷；和 檢測裝置，至少對微細圖案部，使用掃描上述罩幕內之 圖案所獲得之透過率信號之預設透過率缺陷之臨限値，利 用檢測缺陷之方法用來檢測缺陷。 (構成8)—種灰階罩幕之製造方法，其特徵是使用構成1 或2之方法進行缺陷檢查。 (構成9)一種光罩幕之製造方法，其特徵是使用構成3或4 之方法進行缺陷檢查。 其次，依照本發明之灰階罩幕之檢查方法和檢查裝置 時，對於掃描灰階部所獲得之透過率信號，當在透過率信 號具有圖1 (2)所示之週期性之變動之情況時，就施加模糊 處理用來使該信號平坦化，因此可以成爲如圖1(3)所示之 透過率信號，本來之透過率特性（灰階罩幕使用時之透過率 18 312/發明說明書(補件)/92-06/92108791 1223061 特性），例如可以修正成爲5 0 %附近之均一之透過率信號。 另外，根據該信號進行缺陷檢查，在不進行模糊處理之情 況，對被檢測爲透過率信號之疑似缺陷之位置’可以檢查 成爲不會檢測爲疑似缺陷。因此，在不進行模糊處理之情 況時，對於被檢測爲透過率信號之疑似缺陷之位置，可以 保證其透過率。 另外，本發明之模糊處理是在測定區域信號最平坦之 點，對所獲得之信號進行之模糊處理，該模糊處理可以利 用習知之圖像處理所使用之模糊功能等。 另外，在本發明中因爲亦可以獲得與上述之模糊處理同 樣之效果，所以對於掃描該灰階部所獲得之透過率信號， 可以施加修正處理，使其近似灰階部之透過率特性。 在本發明中，上述之灰階部之透過率缺陷之臨限値，最 好將透過率缺陷抽出臨限値設定在超過圖8所示之灰階部 所特有之基準信號位準1 6之位準。利用此種方式可以排除 灰階部所特有之基準信號位準之影響。在此種情況，透過 率缺陷抽出臨限値最好設置成以基準信號位準1 6之中心 値作爲基準。另外，經由將透過率缺陷抽出臨限値設定在 灰階部之容許透過率之上限和下限，可以保證該灰階部之 透過率。 另外，通常之半導體用灰階罩幕因爲尺寸小，所以需要 某種程度之工夫和時間，利用與顯微鏡形成一體之透過檢 查機等，可以進行灰階部等之透過率檢查，但是在LCD製 造用灰階罩幕之情況時，尺寸變大，在不進行該部份之上 19 312/發明說明書(補件)/92-06/92108791 1223061 述之模糊處理之情況時，因爲被檢查爲透過率信號之疑似 缺陷之位置很多，所以在此種檢查方法中工程負擔極大’ 實際上進行此種透過率檢查會有困難，因此，本發明之缺 陷檢查方法在使LCD製造用灰階罩幕實用化上是不可欠 缺者。 此種情況不只限於LCD (液晶顯示器）製造用罩幕，亦同 樣適用在其他之顯示裝置。另外，在LCD製造用罩幕，包 含 LCD之製造所必要之所有之罩幕，例如，用以形成 TFT (薄膜電晶體），低溫多晶矽TFT，彩色過濾器等之罩 幕。在其他之顯示裝置製造用罩幕包含有有機EL(電介質） 顯示器，電漿顯示器等之製造所需要之所有之罩幕。 另外，依照本發明之光罩之製造方法和製造裝置時，例 如對於光罩之線幅爲3 // m以下之線和空白之微細而且高 精確度之圖案，對掃描圖案部所獲得之信號進行模糊處 理，可以獲得均一之透過率，根據該信號進行形狀或尺寸 等之缺陷檢查，可以成爲微細而且高精度之缺陷檢測。 包含此種微細圖案之光罩有LCD製造用光罩和有機EL 顯示器，電漿顯示器等之顯示裝置製造用光罩，以及用以 形成TFT通道部或接觸孔部等之具有微細圖案之光罩等。 【實施方式】 下面將具體的說明具有灰階部之灰階罩幕之缺陷檢查方 法和缺陷檢查裝置。 (實施例1) 實施例1如圖2(1)所示，用來進行灰階部（透過率30%) 20 312/發明說明書(補件)/92-06/92108791 1223061 之缺陷檢查。 此處所使用之缺陷檢查裝置是具有下面所述之構造之裝 置。 缺陷檢查裝置具有檢查裝置，利用平行光源和受光透鏡 用來掃描形成在罩幕內之圖案，藉以檢測透過率信號。實 質上，例如具有：平行光源（與透鏡對應之點光源或罩幕全 面照射光源），被設在罩幕之一側；受光透鏡，被設在罩幕 之另外一側；和掃描裝置（通常爲罩幕台移動裝置），用來 使罩幕和透鏡相對的移動，藉以掃描罩幕之全體區域；利 用該等，沿著掃描方向以透鏡接受透過光。另外，例如利 用被配置在透鏡單位內之CCD線感測器用來檢測透過率 信號。 另外，該缺陷檢查裝置所具備之功能是對檢測到之透過 率信號進行模糊處理。 透過率信號具有灰階部之透過率缺陷抽出臨限値和通常 部之透過率缺陷抽出臨限値，被發送到缺陷檢測電路，藉 以判定透過率缺陷。在缺陷檢測電路，具有一定時間中間 區域之透過率之透過率信號，在超過灰階部用透過率缺陷 抽出臨限値之上限或下限之情況時，就判定爲灰階部之透 過率缺陷。另外，當一定時間透過率〇%近邊之透過率信 號，高於遮光部用透過率缺陷抽出臨限値之情況時，就判 定爲遮光部之透過率缺陷。‘同樣的，當一定時間透過率 100%近邊之透過率信號，低於透過部用透過率缺陷抽出臨 限値之情況時，就判定爲透過部之透過率缺陷。在該等情 312/發明說明書(補件)/92-06/92108791 2 1223061 況，不判定邊緣信號等爲透過率缺陷。 使用此種裝置以下列之步驟進行缺陷檢查。 首先，在灰階部使檢查裝置之透鏡依照圖2 (1)之箭頭之 方向進行掃描，利用被配置在透鏡單位內之CCD線感測 器，檢測透過率信號。這時之透過率信號如圖2(2)所示。 其次，使用上述之裝置所具備之模糊處理功能，用來進 行模糊處理。在該模糊處理時，首先爲著決定最佳之模糊 點成爲透過率爲30%之一定之透過率信號，所以進行如圖 2(3)所示之變化模糊量之實驗，決定圖2(4)作爲最佳之模 糊點。然後，依照該過濾係數進行模糊處理。 其次，如圖2(4)所示，利用上述步驟所決定之模糊處理 後之透過率信號進行檢查，在未進行模糊處理之情況時’ 被檢測爲透過率信號之疑似缺陷之位置，可以檢查成不會 檢測爲疑似缺陷。因此，在未進行模糊處理之情況時’對 於被檢測爲透過率信號之疑似缺陷之位置，可以保證其透 過率。 (實施例2) 在實施例2中，進行檢查之灰階部，除了圖3(1)之線幅 錯誤之灰階部外，使用與實施例1同樣之方法進行檢查。 圖3 (2)是使圖3 (1)之灰階部依照箭頭方向掃描時之透過 率信號。 圖3 (3 )是對該透過率信號施加模糊處理後之透過率信 號。 預先使用缺陷臨限値（被設定之位準超過灰階部特有之 22 312/發明說明書(補件)/92-〇6/92108791 1223061 基準信號位準）用來進行檢查，如圖3 (4)所示，可以根據線 幅錯誤用來檢測透過率缺陷。在未進行與實施例1同樣之 模糊處理之情況時’檢測到有透過率信號之疑似缺陷之位 置’可以檢查成不會檢測爲疑似缺陷。因此，在未進行模 糊處理之情況時，對於檢測到有透過率信號之疑似缺陷之 位置，可以保證其透過率和線幅。 (實施例3) 在實施例3中，對於在線和空白狀之灰階部（透過率 5 〇 % )，具有微小突起缺陷（黑缺陷）之情況，使用與實施例 2同樣之方法進行檢查。其結果與圖3(4)所示者同樣的， 可以根據微小突起缺陷用來檢測透過率缺陷。 另外，本發明並不只限於上述之實施形態等。 在上述之實施例中只說明灰階部之缺陷檢查，但是亦可 以如先前之日本國專利案特願200 1 -24407 1號所說明之方 式，同時進行遮光部和透光部之透過率缺陷檢查。但是， 在遮光部和透光部之檢查時，不需要模糊處理。 另外，在上述之實施例中，所述者是灰階罩幕之灰階部 之檢查，但是本發明並不只限於此種方式，例如亦可適用 在TFT通道部形成用光罩等，和適用在包含有與上述灰階 部同樣之微細圖案之光罩等。這時，在不進行模糊處理之 情況，對於檢測到有透過率信號之疑似缺陷之位置，可以 檢查成不會檢測爲疑似缺陷，可以進行高精確度之缺陷檢 查。 下面將使用圖4用來說明本發明之檢查方法。 23 312/發明說明書(補件)/92-06/921〇8791 1223061 步驟1:獲得具有遮光部，透光部，和灰階部之灰階罩幕 之透過率信號。 步驟2 :將步驟1所獲得之透過率信號輸入到比較檢查用 之缺陷判定電路，用來進行比較檢查。 步驟3 :對於步驟1所獲得之透過率信號，識別是遮光 部，透光部和灰階部之那一方之區域之透過率信號，只抽 出灰階位準之透過率信號。 步驟4 ·_將步驟3所抽出之透過率信號輸入到透過率檢查 用之缺陷判定電路，用來進行透過率檢查。 下面詳細的說明步驟1。 在此步驟獲得可以使用在步驟2之比較檢查之透過率信 號。亦即，在步驟2之比較檢查是同一罩幕內之相同圖案 間之比較檢查之情況時，使用2個之透過率檢測裝置用來 檢測成爲比較對象之相同圖案之各個之透過率信號（以2 個之透鏡測定），在步驟2之比較檢查是圖案和資料之比較 檢查之情況時，使用1個之透過率檢測裝置（1個之透鏡） 用來獲得圖案之透過率信號。 其次，在步驟2進行通常之比較檢查，例如進行下面所 說明之圖案間之比較之比較檢查。 圖5(1)表示在遮光部1產生白缺陷4(針孔），在透過部2 產生黑缺陷5(點），在灰階部3產生白缺陷6(圖案欠缺）之 狀態，箭頭表示比較檢查裝置之一方之透鏡（上透鏡）之掃 描之方式。 圖5(2)表示沿著上述掃描線所獲得之透過率信號7。透 24 3口/發明說明書(補件)/92-06/92108791 1223061 過率信號7之位準在遮光部1爲B，在透過部2爲W，在 灰階部3爲G，遮光部1之透過率被設定爲0 %，透過部2 之透過率被設定爲100%。透過率信號7基本上由在圖案邊 緣（遮光部，透過部，灰階部之各個境界）所產生之圖案邊 緣線信號（圖案形狀信號）構成，在產生有缺陷之情況，出 現在遮光部1產生之白缺陷信號4，在透過部2產生之黑 缺陷信號5 ’，和在灰階部3產生之白缺陷信號6 ’等。 圖5(3)表示在未產生有與圖5(1)相同之圖案之缺陷之情 況時，利用另外一方之透鏡（下透鏡）所獲得之透過率信號 7 ’。另外，因爲灰階部3是微細（和S圖案，所以與該微細 圖案對應的，如圖1 1所示，在灰階部產生特有之基準信號 位準6”（雜訊帶）。 圖5 (4)是減算（差分）各個透鏡所獲得之透過率信號，用 來求得差信號。亦即，從圖5 (2)之透過率信號7中減去圖 5(3)之透過量信號7’用來求得差信號8。在差信號8，從各 個透鏡之透過量信號除去圖案邊緣線信號，只抽出圖案缺 陷信號4 ’、5 ’、6 ’。 圖5(5)表示在只抽出圖案缺陷信號之差信號8，抽出遮 光部1和透過部2之缺陷所需要之臨限値（正側9a、負側 9b)之設定狀態。在此處不能抽出灰階部3之缺陷。 下面將詳細的說明步驟3。 遮光部·透過部和灰階部之任何一個區域之識別方法是 例如根據在步驟1所獲得之透過率信號，用來識別任何一 個透鏡之透過率信號之位準是遮光部位準（透過率〇%)，透 25 312/發明說明書(補件)/92-06/92108791 1223061 過部位準（透過率100%)，或灰階位準（透過率50%前後）。 圖6( 1)表示具有遮光部，透過部和灰階部之光罩，箭頭表 示檢查裝置之透鏡之掃描方向（檢查方向）。在此處如圖6(2) 所示，設定某一個一定之中間區域之透過率作爲灰階區域 抽出用臨限値，抽出不超過該臨限値之透過率信號7作爲 灰階區域之透過率信號。 另外，上述之灰階部之透過率缺陷之臨限値最好設定爲 透過率缺陷抽出臨限値，其位準不超過圖1 1所示之灰階部 所特有之基準信號位準1 6。利用此種方式可以排除灰階部 所特有之基準信號位準之影響。在此種情況，透過率缺陷 抽出臨限値之設定最好以基準信號位準1 6之中心値作爲 基準。另外，經由將透過率缺陷抽出臨限値設定在灰階部 之容許透過率之上限和下限，可以保證灰階部之透過率。 其次，在步驟4所進行之檢查如下所述。 在步驟4，當1個透鏡之情況時，對1個之透過率信號 進行以下之檢查，當2個透鏡之情況時，分別對各個之透 過率信號進行以下之檢查。 對於在步驟3所抽出之透過率信號，圖7(1)表示在灰階 部未產生有缺陷之情況，箭頭表示檢查裝置之透鏡之掃描 方向（檢查方向）。圖7(2)表示沿著上述之掃描方向所獲得 之透過率信號7。透過率信號在灰階部例如爲5 0 %。另外， 如圖4(2)所示，例如在灰階部設置透過率缺陷之臨限値（上 限側8a，下限側8b)，當超過該等之臨限値之情況時，就 判斷爲在灰階部產生有透過率缺陷。 26 312/發明說明書(補件)/92-06/92108791 1223061 圖8 (1)表示在灰階部具有缺陷之情況，如圖8 (2)所示， 當在缺陷部份之透過率位準出現變化，該透過率變化超過 透過率缺陷之臨限値之情況時，就判斷爲在灰階部產生有 透過率缺陷。 在上述之說明中，對於步驟2和步驟3〜4，可以以同一 裝置同時進行。 下面將說明本發明之檢查裝置。 本發明之檢查裝置具有用來掃描形成在罩幕內之圖案， 藉以檢測透過率信號之裝置。 實質上具有：透鏡，被設在罩幕之一側；平行光源（與透 鏡對應之點光源或罩幕全面照射光源）’被設在罩幕之另外 一側；和掃描裝置（通常爲罩幕載物台移動裝置），用來使 罩幕和透鏡進行相對移動，藉以掃描罩幕之全體區域；利 用該平行光源和受光透鏡用來掃描形成在罩幕內之圖案， 例如利用被配置在各個透鏡單位內之CCD線感測器，用來 檢測透過率信號。 本發明之檢查裝置包含有透鏡爲1個之單眼檢查機之情 況，和透鏡爲2個以上之多眼檢查機之情況。在多眼檢查 機之情況，包含有：利用2個之透鏡分別掃描形成在罩幕內 之同一圖案部份，藉以檢測與各個透鏡對應之透過率信號 之機構，和使各個透鏡位置對準在形成於罩幕內之同一圖 案部份之機構等。 本發明之裝置具有比較檢查用之缺陷判定電路。實質上 在使圖案之間進行比較和檢查之情況時，具有電路（差分電 27 312/發明說明書(補件)/92-06/92108791 1223061 路）用來使利用2個之透過率檢測裝置（2個之透鏡）所獲得 之2個透過率信號相減（差分），藉以獲得差信號。在比較 檢查是使圖案和資料進行比較之檢查之情況時，具有電路 (差分電路）用來使利用1個之透過率檢測裝置（1個之透鏡） 所獲得之1個透過率信號和資料相減，藉以獲得差信號。 在比較檢查用之缺陷判定電路中，至少對形成有遮光部和 透過部之區域進行檢查。 另外，在本發明之裝置中具有透過率檢查用之缺陷判定 電路。透過率檢查用缺陷判定電路至少對灰階部進行檢 查。實質上，當灰階區域之透過率信號進入到灰階部用之 透過率缺陷區域之情況時，就判定爲灰階部之透過率缺 陷。在單眼檢查機之情況，具有1個之透過率檢查用之缺 陷判定電路，對應到利用1個之透鏡所獲得之1個之透過 率信號。在多眼檢查機之情況，對於利用2個之透鏡所獲 得之2個透過率信號，爲著分別獨立的進行檢查，所以具 有2個之透過率檢查用之缺陷判定電路。 在本發明之裝置中，具有識別裝置（例如識別電路等）， 用來識別遮光部·透過部和灰階部之任何一個之區域。 另外，本發明並不只限於上述之實施形態等。 例如，在灰階部由半透過膜構成之情況時，亦可以使用 本發明。 另外，在上述之實施例中，所述者是灰階罩幕之灰階部 之檢查，但是本發明並不只限於該種方式，例如亦可以使 用在TFT通道部形成用光罩等之包含有與上述灰階部同樣 28 312/發明說明書(補件)/92-06/92108791 1223061 之微細圖案之光罩。 另外，在本發明中，對於圖13(1)所示之掃描灰階部所獲 得之透過率信號，在有圖13(2)所示之週期變動之情況時， 爲著使該信號平坦化所以施加模糊處理，可以成爲圖13(3) 之透過率信號，可以獲得本來之透過率特性之例如50%附 近之均一之透過率信號。另外，本發明之模糊處理是在測 定區域之信號最平坦化之點，對所獲得之信號進行之模糊 處理，該模糊處理可以利用習知之圖像處理所使用之模糊 處理等。另外，根據該模糊處理過之信號進行透過率缺陷 檢查，對於灰階罩幕之灰階部和包含微細圖案之光罩，在 未進行模糊處理之情況時，於檢測有透過率信號之疑似缺 陷之位址，成爲可以保證具有透過率。另外，對於灰階罩 幕之灰階部或包含微細圖案之光罩，在未進行模糊處理之 情況時，對於檢測到透過率信號之疑似缺陷之位置，可能 根據線幅錯誤檢測透過率缺陷或根據微小突起缺陷檢測透 過率缺陷。 另外，在LCD製造用灰階罩幕之情況時，因爲使尺寸變 大就需要多出該部份之檢查時間，所以在比較檢查和透過 率檢查雙方分別進行之檢查方法中，變成爲不實用，因此， 本發明之缺陷檢查方法是LCD製造用灰階罩幕之實用化 所不可欠缺者。依照此種方式，不只限於LCD (液晶顯示器） 製造用罩幕，對於其他之顯示裝置，或TFT通道部形成用 光罩等之具有微細圖案之光罩，或具有線幅爲3 // m以下 之線和空白之微細而且高精度圖案之光罩等亦同。此處之 29 312/發明說明書(補件)/92-06/92108791 1223061 LCD製造用罩幕包含LCD之製造所需要之所有之罩幕’例 如包含TFT(薄膜電晶體），低溫多晶矽TFT，用以形成彩色 過濾器等之罩幕。其他之顯示裝置製造用罩幕包含有機 EL(電介質）顯示器，電漿顯示器等之製造所需要之所有之 罩幕。另外，包含微細圖案之光罩具有LCD製造用光罩或 有機EL顯示器，電漿顯示器等之顯示裝置製造用光罩， 例如用以形成TFT通道部或接觸孔部等之具有微細圖案之 光罩等。 依照以上所說明之本發明時，對檢查裝置所獲得之透過 率信號施加修正處理使其近似灰階罩幕使用時之透過率特 性，所以可以獲得灰階部之高精確度之缺陷之保證和透過 率之保證。另外，對於灰階罩幕之灰階部或包含微細圖案 之光罩，在未進行模糊處理之情況時，被檢測到有透過率 信號之疑似缺陷之位置，可以檢查成不檢測到疑似缺陷。 因此，在未進行模糊處理之情況，對於檢測到有透過率信 號之疑似缺陷之位置，可以保證具有透過率。 另外，對於灰階罩幕之灰階部或包含微細圖案之光罩， 可以進行線幅錯誤之檢測或微小突起缺陷之檢測。 依照以上所說明之本發明時，可以提供缺陷檢查方法和 裝置，對於具有遮光部，透過部，和灰階部之灰階罩幕， 可以以短時間和高精確度進行缺陷檢查。 【圖式簡單說明】 圖1(1)〜（3)用來說明本發明之缺陷檢查方法之槪要。 圖2(1)〜（4)用來說明實施例1之缺陷檢查方法。 30 312/發明說明書(補件)/92-06/92108791 1223061 圖3(1)〜（4)用來說明實施例2之缺陷檢查方法。 圖4用來說明本發明之缺陷檢查方法之槪要。 圖5(1)〜（5)用來說明實施形態之步驟2。 圖6(1)、（2)用來說明實施形態之步驟3。 圖7(1)、（2)用來說明實施形態之步驟4(沒有缺陷之情 況）。 圖8 (1)、（ 2)用來說明實施形態之步驟4 (有缺陷之情況）。 圖9(1)、（2)用來說明灰階罩幕，（1)是部份平面圖，（2) 是部份剖面圖。 圖10(1)〜（5)用來說明習知之缺陷檢查方法。 圖1 1用來說明灰階部所特有之基準信號位準。 圖12(1)、（2)用來說明本申請人先前申請之缺陷檢查方 法。 圖13(1)〜（3)用來說明透過率信號之模糊處理。 (元件符號說明） 1 遮光部 2 透過部 3 灰階部 3a 遮光圖案 3b 透過部 3c 半透過膜 5 灰階部 7 透過率信號 8a 灰階部用之透過率缺陷抽出臨限値（上限） 312/發明說明書(補件)/92-06/92108791 31 1223061 8b 灰 階 部 用 之 透 m 率 缺 陷 抽 出 臨 限 値（下限） 9 a 透 過 部 用 之 透 cm m 率 缺 陷 抽 出 臨 限 値 9b 遮 光 部 用 之 透 過 率 缺 陷 抽 出 臨 限 値 11 白 缺 陷 12 里 y 1 \ \ 缺 陷 13 透 過 率 信 Wi 312/發明說明書(補件)/92-06/92108791 32[223061] Description of the invention [Technical field to which the invention belongs] The present invention relates to a defect inspection method and a defect inspection device for a gray scale mask or a mask including a fine pattern. [Prior art] In recent years, in the field of large LCD screens, attempts have been made to reduce the number of screens using gray scale screens (monthly FPD Intelligence, May 1999). The gray scale mask here is shown in FIG. 9 (1), and has a light shielding portion 1, a transmission portion 2, and a gray scale portion 3 on a transparent substrate. The gray-scale portion 3 is, for example, a region where a gray-scale mask is used to form a light-shielding pattern 3a below the resolution limit of a large LCD exposure machine. The gray-scale portion 3 is formed to reduce the amount of light transmitted through the area and to reduce The irradiation amount in this area can selectively change the film thickness of the photoresist. 3 b is a fine transmission portion below the resolution limit of the exposure machine of the gray scale portion 3. The light-shielding portion 1 and the light-shielding pattern 3 a are usually made of the same material such as chromium or chrome, and are formed of films of the same thickness. Each of the transmission portion 2 and the fine transmission portion 3b is a portion of a transparent substrate on which a light-shielding film or the like is not formed on the transparent substrate. The resolution limit of a large LCD exposure machine using a gray scale mask is approximately 3 // m in the segmentation mode and approximately 4 // m in the mirror projection mode. Therefore, in the gray-scale portion 3 of FIG. 9 (1), the blank width of the transmission portion 3b is set to 3 // m or less, and the line width of the shading pattern 3a below the resolution limit of the exposure machine is set to 3 / zm or less. In the case of using the above-mentioned large LCD exposure machine for exposure, because the light that has passed through the gray-scale portion 3 'will become insufficient in overall exposure', the positive 5 312 / invention specification of exposure through the gray-scale portion 3 Supplement) / 92-06 / 92108791 1223061 type photoresist, which will make the film thickness thin and remain on the substrate. That is, due to the difference in the exposure amount of the resist, the solubility in the developing solution may differ between the portion corresponding to the normal light-shielding portion 1 and the portion corresponding to the gray-scale portion 3. As shown in FIG. 9 (2), the shape of the resist is approximately 1.3 // m at a portion Γ corresponding to the normal light-shielding portion 1, and approximately 3 ′ at a portion 3 'corresponding to the gray-scale portion 3, for example. 3 # m, the portion corresponding to the transmission portion 2 becomes the portion 2 ′ without the resist. Then, the first etching of the substrate 2 is performed on the portion 2 'without the resist, and the resist on the thin portion 3' corresponding to the grayscale portion 3 is removed by ashing, etc., and the second step is performed on this portion. Etching and performing the conventional two-piece mask part with one mask can reduce the number of masks. A conventional inspection method of a mask composed of a light-shielding portion and a transmission portion is, for example, a comparative inspection method, and two optical systems are used to compare the patterns of the masks. This method will be specifically explained below. FIG. 10 (1) shows a state in which white defects 11 (pinholes) are generated in the light-shielding portion 1 and black defects 12 (spots) are generated in the transmission portion. The arrows indicate the lenses of one side of the comparison inspection device (hereinafter referred to as the upper lens). scanning method. Fig. 10 (2) shows the transmittance signal 13 obtained along the scanning line of the lens. The transmittance signal 1 3 is detected by, for example, a CCD line sensor arranged in each lens unit. The levels of the transmittance signals 13 are respectively set to B for the light-shielding section 1 and W for the light-transmitting section 2. The transmittance of the light-shielding section 1 is 0% and the transmittance of the transparent section 2 is 100%. The transmittance signal 13 is basically composed of a pattern edge line signal (pattern shape signal) generated at the edge of the pattern (the boundary between the light-shielding portion and the transmission portion). When a defect occurs, 6 312 / Invention Specification (Supplementary) ) / 9106/92108791 1223061 The white defect signal 1 1 ′ generated in the light shielding portion 1 and the black defect signal 1 2 ′ generated in the transmission portion 2. FIG. 10 (3) shows a transmission signal 1 3 ′ obtained by using a lens of another square (hereinafter referred to as a lower lens) when no defect having the same pattern as that of FIG. 10 (1) is generated. Fig. 10 (4) is the difference signal 14 obtained by subtracting (differentiating) the transmittance signals obtained by each lens. That is, the difference signal obtained by subtracting the transmittance signal 13 'of Fig. 10 (3) from the transmittance signal 13 of Fig. 10 (2). At the difference signal 14, the pattern edge line signal is removed from the transmittance signals of the respective lenses, and only the pattern defect signals 1 Γ, 1 2 ′ are extracted. Fig. 10 (5) shows that only the difference signal 14 of the pattern defect signal is extracted, and the threshold value required to extract the light-shielding portion 1 and the transmission portion 2 is set, and the white defect is detected with the positive threshold value 15a, and the negative side Limit 15b to detect black defects. If the threshold is low, the detection sensitivity will increase, but it needs to be set at a level where no suspected defect is detected. In order to see which kind of defect occurs in which lens, for example, in the upper lens circuit, the signal of the lower lens is compared (the signal of the lower lens is subtracted from the signal of the upper lens), and the light shielding part of the upper lens 1 When a white defect occurs, a defect signal is output on the positive side, and when a black defect is generated on the transmission portion of the upper lens 2, a defect signal is output on the negative side. In this way, the white defect of the upper lens and the Black defects (Figures 10 (2) to (5) above). Similarly, for example, in the circuit of the lower lens, the signal of the upper lens is compared with the signal of the upper lens (the signal of the upper lens is subtracted from the signal of the lower lens). When a white defect occurs in the light shielding portion 1 of the lower lens, it is on the positive side. Output defect 7 312 / Invention specification (Supplement) / 92-06 / 92108791 1223061 When a black defect occurs in the transmission part 2 of the lower lens, a defect signal is output on the negative side, and the lower lens is detected in this way White and black defects. [Summary of the Invention] (Problems to be Solved by the Invention) The above-mentioned conventional comparative inspection method is used to inspect a conventional mask composed of only a light-shielding portion and a transmitting portion, so it is not suitable for inspecting a gray-scale cover having a gray-scale portion. screen. In detail, the conventional comparative inspection method has the problems described below when inspecting the gray scale mask. That is, the defect signal of the gray-scale part becomes weak due to the smallness of the defect itself. When using a conventional comparative inspection device, if the threshold is not lowered than the threshold used in the inspection of the ordinary light-shielding part. , The detection will be difficult. However, for example, in the case where the gray scale portion is a region with a fine pattern below the resolution limit of the exposure machine using a gray scale mask, the fine pattern corresponds to the fine pattern, as shown in FIG. 11. Reference signal level (noise band) 1 6. During comparative inspection, the transmittance obtained by each lens is subtracted (differenced) to obtain the difference signal, and only the pattern defect signal is extracted. However, a slight pattern is generated between the fine shading patterns in the gray scale portion. In the case of deviation, the reference signal level is amplified (maximum 2 times), and those who are not defective will be detected as defects (suspected defects). Therefore, the threshold threshold cannot be reduced, and high-sensitivity inspection cannot be performed as a problem. . In addition, the conventional comparative inspection is to check the white defects or black defects, so the transmission rate of the most important factor in the gray scale mask must be guaranteed. 8 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 Difficult. That is, for example, in the whole area of the mask, when the shaded line width in the gray scale part becomes insufficient (large line width) or too large (small line width) in the designed size, the transmittance tolerance is too large, or the gray scale portion is formed. When the semi-transmissive transmittance exceeds the allowable threshold, the transmittance signals obtained by subtraction are subtracted in a comparison check to obtain a poor signal, and a poor result may occur, and such a transmittance defect may not be detected. This problem is particularly serious when there is no shape defect in the gray scale portion. If the transmittance in the gray scale is within the allowable range, it must be free from defects. However, in the conventional comparative inspection, because the detection is a shape, the person detected by the conventional inspection will become the transmittance. The result is originally allowed. Those who will not be detected as defective will be detected, so the problem of correctness (ability) is checked. In addition, the same problem also occurs in a mask with a fine pattern, such as a TFT channel-shaped mask, or a mask with a fine and high-precision pattern with a line width of 3 // and a blank. For example, the mask for channel formation tends to be rapidly miniaturized as the TFT channel portion is miniaturized. For this kind of pattern, in the case of using the conventional inspection, due to the vibration of the stage of the inspection machine or the image displacement on the inspection machine, suspected defects will occur, and there will be suspected defects in other micrographs. When you fail to detect a suspected defect, you cannot obtain a sensitivity question that can guarantee the level at which the defect is detected. In order to solve this problem, the applicant previously applied for a detection party called a monocular transmittance test), instead of using a comparison to check, the 312 / Invention Specification (Supplement) / 92-06 / 92108791 light map, more than The lens of the film is therefore not particularly a detection range for defects. There will be a specific level of the detection method that uses the light below m to make the pattern method into the lens case. (The following transmittance signal is obtained by scanning the pattern in the mask of 9 1223061. Use the preset transmission. The threshold of the rate defect is used to detect the defect (Japanese Patent Application No. 200 244071). A specific example of the method will be described below. Figure 1 2 (1) shows the light shielding portion 1, the transmission portion 2, and the gray In the case where no defect occurs in any of the steps 3 and 5, the arrow indicates the scanning direction (inspection direction) of the lens of the inspection device. Fig. 12 (2) shows the transmittance signal 7 obtained along the above-mentioned scanning direction. The transmittance signal is 0% in the light-shielding part 1, 100% in the transmissive part 2, and 50% in the gray-scale parts 3 and 5. Here, as shown in FIG. 12 (2), For example, a threshold value for the transmittance defect of the gray scale part (upper limit side 8a, lower limit side 8b) is set, and when these threshold values are exceeded, it is judged that a transmittance defect occurs in the gray scale part. In this case, as shown in FIG. 12 (2), a normal light-shielding portion and a light-transmitting portion are further provided. The threshold of the defect (transmissive part side 9a, light-shielding part side 9b). When the threshold is exceeded, it is determined that there is a transmittance defect in the light-shielding part or the transmissive part. It is best to detect the light-shielding at the same time. The transmissivity defect of the semi-transmittance, such as the reduction defect of the light-shielding property of the part, and the transmissive defect of the transmissive part, etc. In addition, in this case, the transmittance defect extraction threshold for the gray-scale part is used. 8 a, The transmittance defect areas 10a and 10b formed by the transmittance defect extraction thresholds 9a and 9b of 8b and the ordinary light-shielding part and transmissive part can detect the transmittance defect regardless of the inspection area. That is, if the transmittance is entered, When the defect area is 10a or 1 Ob, it can be judged that the inspection area is transparent regardless of the inspection area. 10 312 / Invention Manual (Supplement) / 92-06 / 92108791 1223061 Over-rate defect. When the inspection method described above is used, transmittance can be performed The direct inspection itself can ensure the transmittance with gray scale. In addition, because it is an inspection method without pattern recognition, the unique pattern shape when fine pattern inspection can be avoided Problems caused by suspected defects (thresholds that cannot be reduced). Therefore, thresholds can be reduced to obtain the accuracy (specification) that can meet the requirements of photomasks that include grayscale masks or fine patterns. In addition, because the pattern defect signal is not used according to the comparison of the patterns, but the transmittance defect extraction threshold threshold preset for the transmittance signal is used, it is possible to avoid the difference signal between the transmittance signals obtained during the comparison inspection. The problem of amplification of the reference signal level peculiar to the fine pattern that becomes the problem (the problem that the threshold value cannot be reduced). Therefore, the threshold value can be reduced to obtain a mask that can meet the gray mask or the fine pattern. Sensitivity requiring precision. In addition, since it is not necessary to compare the objects, a monocular examination can be used. In addition, by changing the threshold for extracting the transmittance defect used in the gray scale section, it is possible to ensure that the transmittance meets the exposure conditions of the gray scale mask used by the user. However, in the case where the transmittance of the gray scale portion composed of the fine pattern in FIG. 1 (1) is scanned in accordance with the direction of the arrow to measure according to the above method, the transmittance of the fine pattern region is originally uniform, for example, 50%. In the case where the transmittance along the shape of the fine pattern is changed as shown in FIG. 1 (2), when such a change occurs, it will cause the threshold of the transmittance defect exceeding the gray scale to be exceeded. 11 312 / Invention specification ( Supplement) / 92-06 / 92108791 1223061 (upper limit side 8a, lower limit side 8b), if the suspected lack of transmittance is detected, there will be a problem that the transmittance defect cannot be detected substantially. The transmittance characteristics of the obtained grayscale portion and the properties of the grayscale portion when a transfer pattern is obtained on a resist that actually uses a grayscale transfer substrate may occur due to the optical strip conditions of the exposure device used for the transfer And different situations. Therefore, the conditions of the exposure device used for the transfer should be such that the gray scale portion has a uniform transmittance (for example, 50%). Consider that the transmittance signal of the inspection device is not the case. Another problem also occurs in a mask such as a pattern for forming a TFT channel portion, or a mask having a line width of 3 // m or less and an empty and highly accurate pattern. The present invention is intended to solve the above-mentioned problems, and an object thereof is to provide a defect detection method and a defect inspection device. As shown in FIG. 1 (2), the transmittance is changed along a fine shape, and at a position where a transmittance signal is detected, It can be checked that the position will not be detected as a suspected defect. In addition, the above-mentioned separate transmittance signal and its transmission threshold are used to directly check the transmittance itself. In this rate check, the pattern is not performed. It is difficult to identify the inspection method for the shape defect (white defect, black defect) of the light-shielding part and the transmission part. Therefore, to perform a high-precision inspection with a light-shielding portion, a light-transmitting portion, and a gray-scale mask, it is necessary to perform both inspection including the pattern inspection and transmittance inspection without the pattern recognition, and many inspection time problems. The same problem also occurs in masks with fine patterns, such as part-forming masks, and 312 / Invention Specification (Supplements) / 92-06 / 92108791, so the inspection device mask is in the transmission rate special part. The setting is set, but externally, it also has a fine white fine pit check pattern which is suspected of pitting. The rate defect is drawn through a single eye, so the inspection will be conducted. The grayscale part will have a recognition ratio. There will be a TFT channel with a line width of 3 12 1223061 # m or less and a mask with a fine and high-precision pattern. The present invention is intended to solve the above-mentioned problems, and an object thereof is to provide a defect inspection method and a defect inspection device. In a gray scale mask having a light shielding portion, a transmission portion, and a gray scale portion, defects can be performed in a short time and with high accuracy. an examination. (Means for Solving the Problems) The present invention has the following constitutions. (Composition 1) A defect inspection method of a grayscale mask, which is used to inspect the grayscale portion of the grayscale mask. The grayscale mask has: a light shielding portion; a transmission portion; and a grayscale portion. The purpose is to adjust the transmission. The area after the measurement reduces the amount of light transmitted through the area and is used to selectively change the film thickness of the photoresist; the above-mentioned gray-scale portion is formed by the resolution limit of the exposure machine using the gray-scale mask. The following area structure of the light-shielding pattern; The defect inspection method is characterized in that the steps include: scanning the above-mentioned gray-scale portion to obtain a transmittance signal; applying a correction process to the above-mentioned transmittance signal to make it approximate the above The transmittance characteristics of the gray scale part when the gray scale cover is used; and when the transmittance signal after the correction process described above exceeds the threshold of the transmittance defect of the gray scale part, it is judged as The gray-scale portion is defective. (Composition 2) —A defect inspection method of a grayscale mask, which is used to inspect the grayscale portion of the grayscale mask. The grayscale mask has: a light shielding portion; a transmittance; and a grayscale portion. The purpose is to adjust The area after transmission reduces the amount of light transmitted through the area and is used to selectively change the film thickness of the photoresist. The above-mentioned gray-scale portion is formed by an exposure machine using the gray-scale mask. Shading below the limit 13 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 The area structure of the pattern; The characteristic of this defect inspection method is that the steps include: Scan the above-mentioned gray-scale part to obtain Transmittance signal; when the above-mentioned transmittance signal has a periodic variation, 'apply a blur to flatten the signal; and when the transmittance signal after the above-mentioned blur treatment exceeds the preset gray-scale transmission When the threshold of the rate defect is rampant, it is judged that a defect is generated in the gray scale portion. (Composition 3) —A defect inspection method of a photomask, which is used to inspect a fine pattern portion of the photomask. The photomask has a light-shielding portion, a transmission portion, and a fine pattern portion. : Scan the above-mentioned fine pattern part to obtain a transmittance signal; When the above-mentioned transmittance signal has a periodic variation, apply a blurring process to flatten the signal; and when the above-mentioned blurring process is transmitted, When the transmittance signal exceeds a predetermined threshold of the transmittance of the fine pattern portion, it is determined that a defect occurs in the fine pattern portion. (Composition 4) In the defect inspection method of the mask of constitution 3, wherein the above-mentioned fine pattern portion is to periodically change the transmittance signal, when the threshold of the transmittance defect of the fine pattern portion is exceeded, Detects a suspected defect in transmittance. (Composition 5) A kind of defect inspection device for inspecting a gray-scale mask, the gray-scale mask having: a light-shielding portion; a transmission portion; and a gray-scale portion, the purpose of which is to adjust the transmission area to allow transmission through the area. The light transmittance of the area is reduced. It is used to select the film thickness of 14 312 / Invention Manual (Supplement) / 92-06 / 92108791 1223061. The defect inspection device is characterized by: The pattern formed in the mask is scanned by the parallel light source and the light receiving lens to detect the transmittance signal; a correction processing device is applied to apply the correction processing to the above transmittance signal so that it approximates the gray level when the gray scale mask is used Transmittance characteristics (for example, when the above-mentioned transmittance signal periodically changes, the blur is applied to flatten the signal); the setting device sets at least the transmittance defect of the gray-scale part for the above-mentioned transmittance signal. Threshold threshold; and a judging device, when the threshold threshold is exceeded, it judges that a transmittance defect is generated in the gray scale portion. (Composition 6) A defect inspection device for inspecting a photomask having a light-shielding portion, a transmission portion, and a fine pattern portion that is generally difficult to inspect. The defect inspection device is characterized by having: a detection device. The light source and the light receiving lens scan the pattern formed in the mask to detect the transmittance signal; apply a correction processing device to apply the correction processing to the above transmittance signal so that it approximates the grayscale portion of the grayscale mask in use Transmittance characteristics (for example, when the aforementioned transmittance signal is periodically changed, blurring is applied to flatten the signal); the setting device sets at least the threshold of the transmittance of the fine pattern portion for the aforementioned transmittance signal値; and a judging device, when the threshold value 超过 is exceeded, it judges that a defect is generated in the fine pattern portion. 15 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 (Composition 7) —A manufacturing method of a gray scale mask, which is characterized by a defect inspection step, and uses the method of constitution 1 or 2 for defect inspection. (Composition 8): A method for manufacturing a photomask, which is characterized by having a defect inspection step, and inspecting the defect by using the constitution 3 or 4. The present invention also has the following structure. (Composition 1) A defect inspection method of a grayscale mask for inspecting the grayscale mask, the grayscale mask having: a light-shielding portion; a transmission portion; and a grayscale portion, the purpose of which is to adjust the area after transmission 'Reduces the amount of light transmitted through the area, and selectively changes the film thickness of the photoresist. The defect inspection method is characterized by the steps involved .... For areas where at least a light-shielding portion and a transmitting portion are formed Using the transmittance signal obtained by scanning the pattern in the mask, use the comparison inspection method to detect defects based on the comparison of the patterns 'use the threshold of the pattern defect preset for the pattern defect signal'; and at least the gray scale The threshold value of the default transmittance defect using the transmittance signal obtained by scanning the pattern in the mask screen is used to detect the defect using the method of detecting the defect. (Composition 2) Defect inspection method for the gray-scale mask of constitution 1 'wherein the above-mentioned gray-scale portion is constituted by using the gray-scale mask to form a light-shielding pattern below the resolution limit of the exposure machine. (Composition 3) A defect inspection method of a photomask for inspecting a photomask having a light-shielding portion, a transmission portion, and a micro-pattern portion, which is characterized in that the steps include: for an area where at least the light-shielding portion and the transmission portion are formed 'Using the transmittance signal obtained by scanning the pattern in the mask' 'Comparison according to the pattern' uses the pattern defect preset for 16 312 / Invention Manual (Supplement) / 92_〇6 / 92 Ying 791 1223061 pattern defect signal The threshold is used to detect defects, and the defect is detected by using a comparative inspection method; and at least for the fine pattern portion, the threshold value of the predetermined transmittance defect of the transmittance signal obtained by scanning the pattern in the mask is used. To detect defects. (Composition 4) The defect inspection method for the mask of constitution 3, wherein the above-mentioned fine pattern portion is a fine pattern which is relatively difficult to inspect. (Composition 5) The defect inspection method of the photomask of any one of constitutions 1 to 4, wherein the above-mentioned inspection of the gray scale portion is obtained when a plurality of transmittance detection devices are used to obtain the pattern in the scan screen. When the transmittance signal is detected, it is checked separately. (Composition 6) A defect inspection device for inspecting a gray-scale mask, the gray-scale mask having: a light-shielding portion; a transmission portion; and a gray-scale portion, the purpose of which is to adjust the transmission area to allow transmission through the area. The light transmittance of the area is reduced, which is used to selectively change the film thickness of the photoresist. The defect inspection device is characterized by: a detection device for scanning a pattern formed in the mask to detect a transmittance signal; The identification device is used to identify the area of the light-shielding portion, the transmission portion and the gray-scale portion. The detection device, for the area where at least the light-shielding portion and the transmission portion is formed, uses the transmittance signal obtained by scanning the pattern in the mask. According to the comparison of the patterns, use the threshold of the pattern defect preset for the pattern defect signal to detect the defects, and use the comparative inspection method to detect the defects; and the detection device, at least for the grayscale portion, scan the pattern inside the mask 17 312 / Invention Manual (Supplement) / 92-06 / 92108791 1223061 The threshold value of the default transmittance defect of the transmittance signal obtained is used to detect defects by the method of detecting defects. (Composition 7) A defect inspection device for a photomask, which includes a light-shielding portion, a transmission portion, and a fine pattern portion. The defect inspection device is characterized by having: a detection device for scanning a pattern formed in the mask To detect the transmittance signal; the identification device is used to identify the area of the light-shielding portion, the transmission portion and the fine pattern portion; the detection device, for the area where at least the light-shielding portion and the transmission portion is formed, scans Based on the comparison of the patterns, the transmittance signals obtained by the patterns are detected using the threshold of the pattern defects preset for the pattern defect signals, and the defects are detected by the comparative inspection method; and the detection device is used to scan at least the fine pattern portions using the above The threshold of the default transmittance defect of the transmittance signal obtained by the pattern in the mask is used to detect the defect by using the method of detecting the defect. (Composition 8) —A method for manufacturing a gray scale mask, which is characterized by using the method of constitution 1 or 2 for defect inspection. (Composition 9) A method for manufacturing a photomask, which is characterized in that defect inspection is performed by the method of constitution 3 or 4. Secondly, according to the inspection method and inspection device of the gray scale mask of the present invention, for the transmittance signal obtained by scanning the gray scale portion, when the transmittance signal has a periodic variation as shown in FIG. 1 (2) At this time, blur processing is applied to flatten the signal, so it can become the transmittance signal as shown in Figure 1 (3), and the original transmittance characteristics (transmittance 18 312 when the gray-scale mask is used) (Supplement) / 92-06 / 92108791 1223061), for example, it can be corrected to a uniform transmittance signal around 50%. In addition, a defect inspection is performed based on this signal, and the position of a suspected defect detected as a transmittance signal can be inspected so as not to be detected as a suspected defect if no blurring is performed. Therefore, in the case where no blurring is performed, the transmittance can be guaranteed for the position where a suspected defect is detected as the transmittance signal. In addition, the blurring process of the present invention is a blurring process on the obtained signal at the point where the signal in the measurement area is the flattest. This blurring process can use the blurring function used in conventional image processing. In addition, in the present invention, since the same effect as that of the above-mentioned blur processing can be obtained, a correction process can be applied to the transmittance signal obtained by scanning the gray scale portion to approximate the transmittance characteristics of the gray scale portion. In the present invention, the threshold value of the transmittance defect of the gray-scale portion is preferably set to exceed the reference signal level 16 unique to the gray-scale portion shown in FIG. 8. Level. In this way, the influence of the reference signal level peculiar to the gray scale can be eliminated. In this case, the transmittance defect extraction threshold 値 is preferably set to the center 位 of the reference signal level 16 as a reference. In addition, by setting the transmittance defect extraction threshold 値 at the upper and lower limits of the allowable transmittance of the gray scale portion, the transmittance of the gray scale portion can be ensured. In addition, the general gray scale cover for semiconductors requires a certain amount of time and time because of its small size. The transmission inspection of gray scales and other parts can be performed using a transmission inspection machine integrated with a microscope. In the case of using a gray scale cover, the size becomes larger. When the obscuration described in 19 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 is not performed, it is checked as being transparent. There are many suspected defects in the rate signal, so the engineering burden is extremely large in this inspection method. In fact, it is difficult to perform such a transmittance inspection. Therefore, the defect inspection method of the present invention makes the gray scale cover for LCD manufacturing practical. Transformation is indispensable. This case is not limited to LCD (liquid crystal display) manufacturing screens, but is also applicable to other display devices. In addition, the mask for LCD manufacturing includes all the masks necessary for manufacturing the LCD, for example, masks for forming a TFT (thin film transistor), a low temperature polycrystalline silicon TFT, and a color filter. Other screens for manufacturing display devices include all screens required for the manufacture of organic EL (dielectric) displays and plasma displays. In addition, when the method and apparatus for manufacturing a photomask according to the present invention, for example, for a fine and highly accurate pattern with a line width of 3 // m or less and a blank, the signal obtained by scanning the pattern portion By performing blur processing, uniform transmittance can be obtained, and defect inspection such as shape or size can be performed based on the signal, which can be used for minute and high-precision defect detection. Photomasks containing such fine patterns include photomasks for LCD manufacturing, organic EL displays, plasma display and other display device manufacturing masks, and photomasks with fine patterns for forming TFT channel portions or contact hole portions. Wait. [Embodiment] A defect inspection method and a defect inspection device for a gray scale mask having a gray scale portion will be specifically described below. (Embodiment 1) As shown in FIG. 2 (1), Embodiment 1 is used for defect inspection of the gray scale section (transmittance 30%) 20 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061. The defect inspection device used here is a device having a configuration described below. The defect inspection device has an inspection device that uses a parallel light source and a light-receiving lens to scan a pattern formed in a mask to detect a transmittance signal. Essentially, for example, there are: a parallel light source (a point light source corresponding to a lens or a full-illumination light source of the cover), provided on one side of the cover; a light receiving lens, provided on the other side of the cover; and a scanning device (typically It is a mask stage moving device), which is used to move the mask and the lens relative to scan the entire area of the mask; using these, the lens receives transmitted light along the scanning direction. In addition, for example, a CCD line sensor arranged in a lens unit is used to detect a transmittance signal. In addition, the defect inspection device has a function to blur the detected transmittance signal. The transmittance signal has a transmittance defect extraction threshold of the gray scale portion and a transmittance defect extraction threshold of the normal portion, and is transmitted to a defect detection circuit to determine a transmittance defect. In the defect detection circuit, when the transmittance signal with the transmittance in the middle region of a certain time exceeds the upper or lower limit of the threshold value of the transmittance defect extraction threshold for the grayscale part, it is determined as the transmittance defect of the grayscale part. In addition, when the near-side transmittance signal with a transmittance of 0% near a certain time is higher than the threshold value of the transmittance defect extraction threshold of the light-shielding portion, it is determined as the light-transmittance defect of the light-shielding portion. ‘Similarly, when the near-side transmittance signal with a transmittance of 100% near a certain time is lower than the transmittance defect extraction threshold 透过 of the transmission section, it is determined as the transmission section transmission defect. In these cases 312 / Invention Specification (Supplement) / 92-06 / 92108791 2 1223061, it is not judged that the edge signal, etc., is a transmittance defect. Use this device to perform defect inspection in the following steps. First, the lens of the inspection device is scanned in the direction of the arrow in FIG. 2 (1) in the gray scale portion, and the transmittance signal is detected by a CCD line sensor arranged in the lens unit. The transmittance signal at this time is shown in Figure 2 (2). Secondly, the blur processing function provided by the above device is used for blur processing. In this blurring process, in order to determine the optimal blurring point, it becomes a certain transmittance signal with a transmittance of 30%. Therefore, an experiment of varying the amount of blurring as shown in FIG. 2 (3) is performed to determine FIG. 2 (4). ) As the best blur point. Then, blur processing is performed according to the filter coefficient. Secondly, as shown in Figure 2 (4), the transmittance signal after the blurring process determined by the above steps is used for inspection. When the blurring process is not performed, the position of the suspected defect detected as the transmittance signal can be inspected. Success will not be detected as a suspected defect. Therefore, in the case where no blurring is performed, the transmission rate can be guaranteed for the position of the suspected defect that is detected as the transmittance signal. (Embodiment 2) In Embodiment 2, the gray scale portion to be inspected was inspected in the same manner as in Embodiment 1 except that the gray scale portion having the wrong line width in Fig. 3 (1). Fig. 3 (2) is a transmittance signal when the gray scale portion of Fig. 3 (1) is scanned in the direction of the arrow. Figure 3 (3) shows the transmittance signal after blurring the transmittance signal. The defect threshold is used in advance (the set level exceeds 22 312 / Invention Specification (Supplement) / 92-〇6 / 92108791 1223061 reference signal level peculiar to the gray level part) for inspection, as shown in Figure 3 (4 ), Can be used to detect transmittance defects based on line width errors. When the same blurring processing as in Example 1 is not performed, 'the position where a suspected defect with a transmittance signal is detected' can be checked so that it is not detected as a suspected defect. Therefore, in the case where no blurring is performed, the transmittance and line width can be guaranteed for the position where a suspected defect of the transmittance signal is detected. (Example 3) In Example 3, in the case where the gray-scale portions (transmittance 50%) having in-line and blank shapes had minute protrusion defects (black defects), the same method as in Example 2 was used for inspection. The result is the same as that shown in FIG. 3 (4), and can be used to detect a transmittance defect based on a small protrusion defect. The present invention is not limited to the above-mentioned embodiments and the like. In the above-mentioned embodiment, only the defect inspection of the gray-scale part is described, but the transmittance defect of the light-shielding part and the light-transmitting part may be performed at the same time as described in the previous Japanese Patent Application No. 200 1 -24407 1. an examination. However, during inspection of the light-shielding portion and the light-transmitting portion, blurring is not required. In addition, in the above-mentioned embodiment, the above is the inspection of the gray-scale portion of the gray-scale mask, but the present invention is not limited to this method. For example, it can be applied to a mask for forming a TFT channel portion, and the like. A photomask or the like including a fine pattern similar to the grayscale portion. In this case, without performing the blurring process, the position where a suspected defect with a transmittance signal is detected can be checked so that it is not detected as a suspected defect, and a highly accurate defect inspection can be performed. The inspection method of the present invention will be described below using FIG. 23 312 / Invention Specification (Supplement) / 92-06 / 921〇8791 1223061 Step 1: Obtain the transmittance signal of the gray scale cover with the light shielding part, the light transmitting part, and the gray scale part. Step 2: The transmittance signal obtained in step 1 is input to a defect determination circuit for comparison inspection for comparison inspection. Step 3: For the transmittance signal obtained in step 1, identify the transmittance signal in the area of the light-shielding part, the light-transmitting part, and the gray-level part, and extract only the gray-level transmittance signal. Step 4 · _ The transmittance signal extracted in step 3 is input to the defect determination circuit for transmittance inspection, and is used for transmittance inspection. Step 1 is explained in detail below. In this step, a transmittance signal is obtained which can be used for the comparative check in step 2. That is, in the case where the comparison check in step 2 is a comparison check between the same patterns in the same mask, two transmittance detection devices are used to detect the transmittance signals of each of the same patterns that are to be compared (using the 2 lens measurement), when the comparison check in step 2 is a comparison check of the pattern and the data, use a transmittance detection device (1 lens) to obtain the transmittance signal of the pattern. Next, a normal comparison check is performed in step 2, for example, a comparison check for comparison between patterns described below. FIG. 5 (1) shows a state in which white defects 4 (pinholes) are generated in the light-shielding portion 1, black defects 5 (spots) are generated in the transmission portion 2, and white defects 6 (pattern lacking) are generated in the gray scale portion 3. The arrows indicate comparison. Check the scanning method of the lens (upper lens) on one side of the device. FIG. 5 (2) shows the transmittance signal 7 obtained along the scanning line. Transparent 24 3 ports / Instruction Manual (Supplement) / 92-06 / 92108791 1223061 The level of the over-rate signal 7 is B in the light-shielding part 1, W in the light-transmitting part 2, G in the gray-scale part 3, and light-shielding part 1. The transmittance is set to 0%, and the transmittance of the transmission section 2 is set to 100%. The transmittance signal 7 is basically composed of a pattern edge line signal (pattern shape signal) generated at the edge of the pattern (shading portion, transmission portion, and gray level portion). When a defect occurs, it appears in the light shielding portion 1 The white defect signal 4 generated, the black defect signal 5 ′ generated in the transmission section 2, and the white defect signal 6 ′ generated in the gray scale section 3 and the like. Fig. 5 (3) shows the transmittance signal 7 'obtained by using the other lens (lower lens) when no defect with the same pattern as in Fig. 5 (1) is generated. In addition, because the grayscale portion 3 is a fine (and S pattern), corresponding to the fine pattern, as shown in FIG. 11, a unique reference signal level 6 ”(noise band) is generated in the grayscale portion. FIG. 5 (4) is the transmittance signal obtained by subtracting (differential) each lens to obtain the difference signal. That is, the transmittance signal of Fig. 5 (3) is subtracted from the transmittance signal 7 of Fig. 5 (2) 7 'is used to obtain the difference signal 8. In the difference signal 8, the pattern edge line signal is removed from the transmission signal of each lens, and only the pattern defect signals 4', 5 ', and 6' are extracted. Figure 5 (5) shows The difference signal 8 of the pattern defect signal is extracted, and the setting state of the threshold value (positive side 9a, negative side 9b) required for the defects of the light shielding portion 1 and the transmitting portion 2 is extracted. The defects of the gray scale portion 3 cannot be extracted here. Step 3 will be described in detail below. The identification method of any one of the light-shielding part, the transmission part, and the gray-scale part is based on the transmittance signal obtained in step 1, and is used to identify the level of the transmittance signal of any lens. It is a light-shielding part (transmittance 0%), transparent 25 312 / invention specification (Supplement) / 92-06 / 92108791 1223061 Passing position standard (transmittance 100%), or gray level (transmittance 50% before and after). Figure 6 (1) shows a mask with a light-shielding part, a transmission part and a gray-scale part. The arrow indicates the scanning direction (inspection direction) of the lens of the inspection device. Here, as shown in Figure 6 (2), the transmittance of a certain intermediate area is set as the threshold for extraction of the grayscale area, and the extraction does not exceed this. The transmittance signal 7 of the threshold value is used as the transmittance signal of the grayscale region. In addition, the threshold value of the transmittance defect of the grayscale part is preferably set to the threshold value of the transmittance defect extraction, and its level does not exceed the figure The reference signal level peculiar to the gray scale section shown in 1 1 16. This method can be used to exclude the effect of the reference signal level peculiar to the gray scale section. In this case, the transmittance defect is extracted from the threshold. The setting is best based on the central signal level of the reference signal level 16. In addition, by setting the transmittance defect extraction threshold 在 at the upper and lower limits of the allowable transmittance of the gray scale portion, the transmittance of the gray scale portion can be ensured. Second, the check performed in step 4 As follows: In step 4, when one lens is used, the following inspection is performed on one transmittance signal. When two lenses are used, the following inspection is performed on each transmittance signal. In the transmittance signal extracted in step 3, Fig. 7 (1) indicates that no defect occurs in the gray scale portion, and the arrow indicates the scanning direction (inspection direction) of the lens of the inspection device. Fig. 7 (2) indicates along the above-mentioned Transmittance signal 7 obtained in the scanning direction. The transmittance signal is, for example, 50% in the grayscale portion. In addition, as shown in FIG. 4 (2), for example, a threshold value (the upper limit side) of the transmittance defect is set in the grayscale portion. 8a, lower limit side 8b). When the threshold is exceeded, it is judged that there is a transmittance defect in the gray scale part. 26 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 Figure 8 (1) shows the situation where there is a defect in the gray scale part, as shown in Figure 8 (2), when the transmission level in the defective part is When a change occurs and the transmittance change exceeds the threshold of the transmittance defect, it is judged that a transmittance defect is generated in the gray scale portion. In the above description, steps 2 and 3 to 4 can be performed simultaneously by the same device. The inspection device of the present invention will be described below. The inspection device of the present invention has a device for scanning a pattern formed in a mask to detect a transmittance signal. Essentially has: a lens, which is provided on one side of the mask; a parallel light source (a point light source corresponding to the lens or a comprehensive illumination light source on the mask) is provided on the other side of the mask; and a scanning device (usually a mask) The stage moving device) is used for relative movement of the mask and the lens to scan the entire area of the mask; the parallel light source and the light receiving lens are used to scan the pattern formed in the mask, for example, by using The CCD line sensor in the lens unit is used to detect the transmittance signal. The inspection apparatus of the present invention includes a case where the lens is a single-eye inspection machine and a case where the lens is a two-eye inspection machine. In the case of a multi-eye inspection machine, it includes a mechanism that uses two lenses to separately scan the same pattern portion formed in the mask, thereby detecting the transmittance signal corresponding to each lens, and aligning the position of each lens at Mechanisms and the like formed in the same pattern part in the mask. The device of the present invention has a defect determination circuit for comparative inspection. Essentially, when comparing and checking patterns, a circuit (differential circuit 27 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061) is provided for using two transmittance detection devices ( The two transmittance signals are subtracted (differential) to obtain a difference signal. In the case where the comparison inspection is a comparison of patterns and data, a circuit (differential circuit) is provided to make one transmittance signal and data obtained by using one transmittance detection device (one lens) Subtract to get the difference signal. In the defect inspection circuit for comparative inspection, at least an area where a light shielding portion and a transmitting portion are formed is inspected. In addition, the apparatus of the present invention includes a defect determination circuit for transmittance inspection. The transmittance inspection defect determination circuit inspects at least the gray scale portion. In essence, when the transmittance signal of the gray-scale region enters the transmittance-defective region for the gray-scale region, it is determined that the transmittance of the gray-scale region is defective. In the case of a monocular inspection machine, there is a defect determination circuit for one transmittance inspection, which corresponds to one transmittance signal obtained by using one lens. In the case of a multi-eye inspection machine, the two transmittance signals obtained by using two lenses are inspected independently for each of the two transmittance signals. Therefore, a defect determination circuit for two transmittance inspections is provided. The device of the present invention includes a recognition device (such as a recognition circuit) for recognizing an area of any one of the light-shielding portion, the transmission portion, and the gray-scale portion. The present invention is not limited to the above-mentioned embodiments and the like. For example, the present invention can also be used when the gray-scale portion is formed of a semi-permeable film. In addition, in the above-mentioned embodiment, the above is the inspection of the gray-scale portion of the gray-scale mask. However, the present invention is not limited to this method. For example, a mask for forming a TFT channel portion may be used. Same as the above-mentioned gray-scale part. 28 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 Fine patterned mask. In addition, in the present invention, the transmittance signal obtained by scanning the grayscale portion shown in FIG. 13 (1) is used to flatten the signal when there is a period variation shown in FIG. 13 (2). Therefore, the blurring process can be applied to the transmittance signal of FIG. 13 (3), and a uniform transmittance signal with a transmittance characteristic of, for example, around 50% can be obtained. In addition, the blurring processing of the present invention is the blurring processing on the obtained signal at the point where the signal in the measurement area is the flattest. The blurring processing can use the blurring processing used in conventional image processing and the like. In addition, transmittance defect inspection is performed based on the blurred signal. For grayscale parts of grayscale masks and masks containing fine patterns, when no blurring is performed, suspected defects of transmittance signals are detected. The address can ensure transmission. In addition, for gray-scale parts of gray-scale masks or masks containing fine patterns, when the blurring process is not performed, for locations where suspected defects of the transmittance signal are detected, the transmittance defect or Transmittance defects are detected based on tiny protrusion defects. In addition, in the case of a gray-scale mask for LCD manufacturing, since the inspection time of the part is required to increase the size, it becomes impractical in the inspection methods performed by both the comparison inspection and the transmittance inspection. Therefore, the defect inspection method of the present invention is indispensable for the practical application of the gray scale cover for LCD manufacturing. In this way, it is not limited to masks for LCD (Liquid Crystal Display) manufacturing. For other display devices, or masks with fine patterns, such as masks for forming TFT channel parts, or with a line width of 3 // m or less The same applies to the lines and the blank masks with fine and high-precision patterns. Here 29 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 The LCD manufacturing screen contains all the screens needed for the manufacture of LCD ', for example, including TFT (thin film transistor), low temperature polycrystalline silicon TFT. To form a curtain of color filters and the like. Other screens for manufacturing display devices include all screens required for the manufacture of organic EL (dielectric) displays and plasma displays. In addition, a mask including a fine pattern includes a mask for manufacturing a display device such as an LCD mask, an organic EL display, and a plasma display. For example, a mask having a fine pattern is used to form a TFT channel portion or a contact hole portion. Wait. In accordance with the invention described above, a correction process is applied to the transmittance signal obtained by the inspection device to approximate the transmittance characteristics of a gray scale mask when used, so it is possible to obtain the guarantee of the high accuracy defect of the gray scale section and Guarantee of transmission rate. In addition, for the gray-scale part of the gray-scale mask or a mask containing a fine pattern, the position where a suspected defect with a transmittance signal is detected without blurring can be checked so that the suspected defect is not detected. Therefore, in the case where no blurring is performed, the transmittance can be guaranteed for the position where a suspected defect with a transmittance signal is detected. In addition, for gray-scale parts of gray-scale masks or masks containing fine patterns, it is possible to detect line width errors or small protrusion defects. In accordance with the present invention described above, a defect inspection method and apparatus can be provided. For a grayscale mask having a light shielding portion, a transmission portion, and a grayscale portion, defect inspection can be performed in a short time and with high accuracy. [Brief description of the drawings] Figures 1 (1) to (3) are used to explain the main points of the defect inspection method of the present invention. 2 (1) to (4) are used to explain the defect inspection method of the first embodiment. 30 312 / Invention Specification (Supplement) / 92-06 / 92108791 1223061 Figures 3 (1) to (4) are used to explain the defect inspection method of the second embodiment. FIG. 4 is used to explain the outline of the defect inspection method of the present invention. 5 (1) to (5) are used to explain step 2 of the embodiment. Figures 6 (1) and (2) are used to explain step 3 of the embodiment. Figures 7 (1) and (2) are used to explain step 4 of the embodiment (when there is no defect). Figures 8 (1) and (2) are used to explain step 4 of the embodiment (in the case of a defect). Figures 9 (1) and (2) are used to illustrate the gray scale mask, (1) is a partial plan view, and (2) is a partial cross-sectional view. Figures 10 (1) to (5) are used to explain the conventional defect inspection method. Figure 11 is used to explain the reference signal level peculiar to the gray scale section. Figures 12 (1) and (2) are used to illustrate the defect inspection method previously applied by the applicant. 13 (1) to (3) are used to explain the blurring processing of the transmittance signal. (Description of element symbols) 1 light-shielding part 2 transmission part 3 gray-scale part 3a light-shielding pattern 3b transmission part 3c semi-transmissive film 5 gray-scale part 7 transmittance signal 8a transmittance defect extraction threshold for gray-scale part (upper limit) 312 / Invention Manual (Supplements) / 92-06 / 92108791 31 1223061 8b Transmitting m-thickness defect extraction threshold for gray scale part (lower limit) 9 a Transmitting cm-thickness defect extraction threshold for transmission part 9b shading part Transmittance defect extraction threshold 値 11 White defect 12 Miles y 1 \ \ Defect 13 Transmittance letter Wi 312 / Invention Specification (Supplement) / 92-06 / 92108791 32