201115264 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種光罩基底用基板，特別係關於一種用 於製造FPD裝置之大型光罩基底用基板。 【先前技術】 近年之電子裝置，特別是半導體元件及液晶顯示器用之 彩色濾光器或TFT元件等，伴隨著it技術之高速發展，被 要求能作更進一步之微細化。支持如此之微細加工技術之 技術之一係使用被稱為轉印光罩之光罩之微影技術。該微 影技術係藉由使曝光用光源之電磁波或光波通過光罩而對 附有抗钮膜之矽晶圓等曝光，而於矽晶圓上形成微細之圖 案。該光罩通常係於形成遮光性膜等薄膜於透光性基板上 而成之光罩基底上，使用微影技術將前述薄膜圖案化，藉 此形成作為轉印圖案之薄膜圖案而製成。 又，為達成圖案之微細化，提高作為用於製造光罩之原 版之光罩基底之品質亦非常重要。半導體用之光罩，除對 基板之主表面施以鏡面研磨外，尚對形成於基板之主表面 周緣之端面亦實施研磨以成特定之鏡面。但’有關液晶顯 示器、有機電激發光顯示器、t歌面才反顯示器等平面顯示 器（FPD : nat Panel Display)之大型光軍，開發當初並未要 求端面為鏡面，其端面係粗面之原狀。如此，端面為粗面 之情形下，無法以洗淨而徹底除去附著於端面之研磨劑或 玻璃成分等污物，洗淨後，此等污物會從彼處剝離而附著 於基板之主表面或主表面上所形成之薄膜或抗蚀膜，成為 146464.doc 201115264 粒子之產生要因，此係成品率低落之要因。 圖4係顯示大型光罩基底用基板之立體圖。該大型光罩 基底用基板10具有表晨2個主表面11與4個端面T。為解決 引起前述成品率惡化之問題，可考慮使大型光罩基底用基 板10之端面T形成為鏡面。 但’於大型光罩基底用基板10開發當初，因大型光罩基 底用基板10之處理難以機械化，故以人手夾持端面T之方 式進行把持。該情形下’對端面τ進行處理時，處理用手 套與大型光罩基底用基板10間會打滑，以致會產生無法把 持大型光罩基底用基板1 〇之問題。 為解決前述問題，針對曝光用大型基板，例如曾有業者 提案使端面具有基板濡濕之狀態下由人把持時不致滑落般 之面粗度’具體而言係使端面之表面粗度Ra為〇 〇5〜0.4 μιη左右（日本特開2005_37580號公報（專利文獻1)}，或使端 面之表面粗度Ra為例如〇.〇3〜0.3 μιη(日本特開2005-300566 號公報（專利文獻2))。 先前技術文獻 專利文獻 專利文獻1:曰本特開2005-37580號公報 專利文獻2 :曰本特開2005-300566號公報（發明專利第 39341 15號公報） 【發明内容】 發明所欲解決之問題 於專利文獻1、2所記載之曝光用大型基板，在該等基板 146464.doc 201115264 申請時，FPD用等之大型光罩，轉印圖案線寬比較寬，相 較於微小的顆粒附著於光罩基底所造成之不良影響，前述 以外問題更為重要。 ^ 但’之後，即使大型光罩’轉印圖案線寬亦朝微細化進 展，顆粒之影響難以忽視。又，伴隨FpD等之大型化及 FPD製造之效率化，光罩基底之大型化亦同步進展。與之 相伴，先前之粗面研磨（未鏡面研磨）基板之端面全周之情 形或使端面T之表面粗度！^為〇 〇3〜〇 4 μηι左右之情形（專: 文獻1、2)’與之前相比，來自基板研磨時之端面之玻璃 碎屑之發生將會增加，已成為問題。 本發明係為解決前述問題而完成者，其目的在於提供一 種光罩基底用基板’其可抑制研磨時來自端面之玻璃碎屑 及研磨齊m留物等顆，粒之產生，_低與之相#之表面缺 陷發生率。 發明人等解析而明瞭下述情事。圖5A〜圓5C係用於說明 玻璃碎屑之發生之圖，圖5八係顯示主表面之研磨時（主表 面右旋轉）之狀態之頂視圖，圖56係顯示主表面之研磨時 (主表面左旋轉）之狀態之頂視圖，圖5C係主表面之研磨時 之端面及載體之側視圖。如同圖所示，在基板1〇由載體31 之基板保持部31a保持之狀態下，載體31係與旋轉基板之 中^同軸％轉，藉由基板保持部3丨&之側壁押壓端面了，基 板1〇會於上下平盤上旋轉。x，為研磨基板1〇之表裏兩方 之主表面11’在具有研磨面34之上平盤32與具有研磨面乃 之下平盤33之間，基板係以被施加特定壓力之方式被夾 146464.doc 201115264 ^由將於摩擦力尚之2個研磨面間被夾持而經加壓之 ^心之基板1〇，以載體31之基板保持部3la之側壁押壓其 端面T，端面T上將被施加較大的力。且，由於以基板丨〇之 中心為軸旋轉，端面T之全面上並非施加同等之力，從基 板對％線11a朝旋轉進行方向側之一半區4，例如，如圖 5A所不使基板1〇順時針旋轉之情形端面τ之區域τ丨上施 加有幾乎全部之力。又，即使是相同區域训，亦從基板 對稱線山朝端面彼此相接之角部p附近，成為施加之力逐 漸增大之荷重分布。又，使基板1〇逆時針旋轉之情形，如 圖5B所示，此次將成為在端面τ之區域丁2具有相同傾向之 荷重刀布。因相同基板i 〇之研磨，係進行順時針與逆時針 之兩方之研磨，故區域T1、丁2上均施加有荷重。因此，基 板10之主表面11之研磨中，對從區域T1與區域T2之角部P 而始之特定長度之區域（即從各端面τ之基板之角部ρ沿主 表面之邊方向特定長度之區域），施加有非常大之力。此 外，為研磨主表面11，上平盤32與下平盤33一併同軸旋 轉。上下平盤32、33之旋轉方向與基板1〇之旋轉方向不同 之情形下，係對抗著加壓狀態下接觸之摩擦力高之研磨面 34、35之旋轉方向而令基板10旋轉，因此對從區域丁丨與區 域Τ2之角部Ρ而始之特定長度之區域，施加有更強之力。 即使是大型光罩基底用基板10之主表面丨丨之兩面研磨之 情形，由上平盤32與下平盤33對基板10施加之每單位面積 之壓力，係與LSI光罩基底用玻璃基板之主表面之兩面研 磨時被施加之壓力為相同程度。即，因大型光罩美底用美 146464.doc 201115264 板10主表面11之面積大出甚多’故施加之荷重亦非常大。 另一方面’端面之主表面側（長邊側）之長度與厚度（短邊側 之長度）之比率’與LSI基板相比’大型光罩基底用基板1〇 更大。即’大型光罩基底用基板10之端面相對於主表面之 面積比率較小，較LSI光罩基底用基板被施加更大之力。 該端面相對於主表面之面積比率，即使尺寸增大，厚度亦 不那麼變厚，故更為顯著。 玻璃碎屑，係先前之對端面全周進行粗面研磨（未鏡面 研磨）之情形或使表面粗度1^為〇.〇3〜〇 4 μπι左右之情形（專 利文獻1、2)下，因端面τ上施加有強大的力時所造成之表 面微小之凸部剝落而發生。從該等驗證，本發明人等所做 出的結論是，因大型光罩基底用基板之尺寸朝大型化進 展，故於兩面研磨時因被載體31之基板保持部3U之側壁 押壓所造成之從各端面T之基板之角部p沿主表面之邊方向 特定長度之區域上被施加之力持續增加，因此玻璃碎屑之 發生率亦增大。又，關於端面T之中央側區域，也得到因 使基板為粗面所造成之玻璃碎屑之發生率，基板尺寸之大 型化幾乎不會對其造成影響之結論，又，本發明人等又發 現藉由將各端面Τ之中央側區域之局部設為粗面，使自基 板之角部Ρ沿主表面之邊方向特定長度之區域為表面粗度 0.5 nm以下之鏡面，可抑制玻璃碎屑之發生，並大幅抑制 與之相伴之基板主表面之表面缺陷（傷痕）之發生率。 本發明中，至少對於端面丁之4隅侧附近之角部侧區域進 行本申清案特定之鏡面研磨，而對於端面T之中央側之中 I46464.doc 201115264 央側區域進行粗面研磨，有以下2個理由。 (1) 對於無法鏡面研磨端面T之全面之大型光罩基底用基 板10 ’抑制玻璃碎屑之發生或研磨劑殘留物之生塵，而實 施表面缺陷對策或生塵對策。 (2) 縮短基板之加工時間。 與鏡面研磨端面τ之全面之情形相比，可縮短端面研磨 之加工時間。其結果，可實現加工之成本降低。 於大型光罩基底之製造步驟中，藉由對基板之端面T實 她本申請案特定之鏡面研磨後再投入主表面11之研磨步 驟’可獲得抑制玻璃碎屑之發生及與之相伴之表面缺陷發 生率較低之效果。又’亦可獲得減少研磨殘留物等之顆粒 發生之效果。根據發明人等之試驗之結果，確認藉由只對 作為強力抵接於基板保持之研磨載體之部分的基板之4隅 附近進行本申請案特定之鏡面研磨，可充分地獲得其效 果。 解決問題之技術手段 本發明具有以下構成。 (構成1) 一種光罩基底用基板，其係由表裏2個主表面 和4個端面所構成之薄板，且於前述端面與前述主表面之 間具有倒角面者，其特徵在於： 前述主表面係一邊之長度為5〇〇 mm以上； 前述端面係包含從鄰接之端面相接之角部沿主表面側之邊 方向特定長度範圍的區域之2個角部側區域、與夾於該2個 角部側區域間之中央側區域； 146464.doc 201115264 前述角部側區域之端面之表面粗度以係〇 5 nm以下之鏡 面； 前述中央側區域係粗面。 (構成2)如構成1所記載之光罩基底用基板，其中前述 中央側區域係表面粗度Ra為5 〇 nm以上之粗面。 (構成3)如構成1或2所記載之光罩基底用基板，其中前 述特定長度係1〇〇 mm以上。 (構成4)如構成1或2所記载之光罩基底用基板，其中前 述主表面之一邊之長度為1000 mm以上，前述特定長度為 1 50 mm以上。 (構成5)如構成1至4中任一項所記載之光罩基底用基 板，其中前述中央側區域包含搬運基板時所把持之區域。 (構成6)如構成1至4中任一項所記載之光罩基底用基 板，其係於製造平面顯示器之光罩基底時使用。 (構成7)—種光罩基底，其係於構成丨至5中任一項所記 載之光罩基底用基板之主表面上具有薄膜。 “（構成8)-種光罩，其係於構成⑴中任—項所記載之 光罩基底用基板之主表面上具有薄膜圖案。 以下’對本發明進行詳細說明。 本發明之光罩基底用基板，係以表裏2個主表面和4個端 =所構成之薄板’且於前述端面與前述主表面之間具有 角面者，其特徵在於： 前述主表面係一邊之長度為5〇〇mm以上； 前述端面係包含從鄰接之端面彼此相接之角 部沿主表 面之 J46464.doc 201115264 邊方向特定長度範圍的區域之2個角部側區域、與夾於該2 個角部側區域間之中央側區域； 刖述角部側區域之端面之表面粗度Ra係〇 5 nm以下之鏡 面； 月J这中央侧區域係粗面（構成1)。 本發明之光罩基底用基板係以表裏2個主表面和4個端面 所構成之薄板，又於端面及主表面之間具有倒角面（構成 1)〇 例如，本發明中，如圖1C所示，係以表襄2個主表面i i 彳4個$而面τ所構成之薄板，又於端面τ與主表面η之間具 有倒角面C。 又’於本發明之光罩基底用基板中，主表面U係一邊之 長度為500 mm以上（構成1)。 例如，本發明中，如圖1B所示，短邊^之長度為5〇〇 mm以上。 又，於本發明之光罩基底用基板中，端面係包含從端面 彼此相接之角部沿主表面之邊方向特定長度範圍之角部側 區域、與夾於兩角部側區域間之中央側區域（構成1)。 Ή如本發明中’如圖1Α所示’端面τ係包含從端面τ 彼此相接之角部沿主表面11之長邊L1方向特定長度（邊L4 之長度）範圍之角部側區域13、與夾於兩角部側區域13間 之中央側區域14。 又，於本發明之光罩基底用基板中，角部側區域之端面 之表面粗度Ra係0 5 nm以下之鏡面（構成1)。 146464.doc •11- 201115264 例如，本發明中，如圖i A所示，角部側區域13之端面τ 之表面粗度Ra係0.5 nm以下之鏡面。又，角部側區域之端 面T之表面粗度Ra若在〇·3 nm以下，則顆粒之發生率可進 一步減少，如此更佳。 又，於本發明之光罩基底用基板中，中央側區域係粗面 (構成1)。 例如，本發明中，如圖1A所示，中央側區域14係粗面。 如此，本發明中，於特定尺寸（―邊長度為5〇〇 mm以上） 之光罩基底用基板中，使4個端面之角部側區域為鏡面， 使4個端面之中央側區域為粗面。此係用於一併解決處理 性、玻璃碎屑之問題。即’因中央側區域之局部區域成為 粗面，故可解決處理性之問題。又，因從載體31之基板保 持部3 la之側壁受到之力較大的角部側區域係形成為鏡 面，故玻璃碎屑之問題亦得到解決。 又，於本發明之光罩基底用基板中，中央側區域宜為表 面粗度Ra為50 nm以上之粗面（構成2)。此係因為可更有效 解決處理之問題。又，作為粗面之中央側區域之表面粗度 Ra之上限，宜為4〇〇 nm。若表面粗度以比4〇〇打爪更粗，則 顆粒之發生率之問題將會顯著。又，設為粗面之中央側區 域若表面粗度|^為300 nm以下，則可謀求顆粒之發生率之 減少’此外表面粗度以為2〇〇 nm以下最佳。 又’於本發明之光罩基底用基才反中，肖定長纟宜為剛 mm以上（構成3)。此係因為可更有效地解決玻璃碎屑之問 題。 146464.doc 12 201115264 又’於本發明之光罩基底用基板中，主表面之一邊之長 度宜為1000 mm以上，前述特定長度宜為150 mm以上（構 成4)。此係因為於主表面之一邊之長度為1〇〇〇 mrn以上之 情形’從載體3 1之基板保持部3 13之側壁所受到之力較大 之區域會變廣’若特定長度為150 mm以上，則可更有效地 解決處理性、玻璃碎屑之問題。又，若特定長度為2〇〇 mm 以上’則可進一步減少玻璃碎屑及顆粒之發生率，因此較 好。又，若無處理性上之問題或基板檢測問題，則若設特 疋長度為300 mm以上’則可進一步減少玻璃碎屑及顆粒之 發生率，故而最佳。 又，於本發明之光罩基底用基板中，中央側區域宜包含 搬運基板時所把持之區域（構成5)。此係因為中央側區域若 包含搬運基板時所把持之區域，則可更有效地解決處理性 之問題。 此外，於大型光罩基底之缺陷檢查裝置、檢查形成於大 型光罩之轉印圖案之光罩檢查裝置、對形成於光罩基底之 抗蝕膜曝光描繪轉印圖案之曝光描繪裝置、曝光裝置等 中存在以光照射於端面T以檢測載臺上之大型光罩基底 或大型光罩之有無之情形。如此之情形下，中央侧區域設 為粗面可謂有效。 又本發明之光罩基底用基板亦可於製造平面顯示器之 光罩基底時使用（構成6)。 又於本發明之光罩基底用基板，亦可於主表面具有薄 膜（構成7)。 146464.doc -13- 201115264 又，於本發明之光罩基底用基板，亦可於主表面具有薄 膜圖案（構成8)。 發明之效果 於本發明之光罩基底用基板中，基板主表面之研磨步驟 時，藉由對端面之中被施加非常大力之基板4隅附近之角 部區域施與鏡面研磨，可大幅減少玻璃碎屑之發生率而 抑制表面缺陷產生率於較低’且’基板主表面之研磨步驟 時，藉由使相對而言施加之力較小之基板之中央側區域為 粗面，可提供處理時等之際容易接受處理之光罩基底用基 板。 【實施方式】 (實施形態1) 首先，使用圖1A〜圖1C、圖2，對本發明之光罩基底用 基板之構造進行說明。圖1係顯示本發明之光罩基底用基 板之構造之圖，圖1A係光罩基底用基板之側視圖，圖1B 係頂視圖，圖1C係側面之局部放大圖。如圖lc所示，本 實施形態之光罩基底用基板10係以表裏2個主表面丨丨及4個 端面T構成之薄板，且於端面τ與主表面丨丨之間具有倒角面 C。如圖1B所示，主表面π係具有一對長邊[1(長邊1丨之 長度：800 mm)與一對短邊L2(短邊L2之長度：5〇〇 mm)之 大致矩形狀。如圖1A、圖1C所示，端面T係包含從端面彼 此相接之角部沿主表面11之邊方向100 mm(邊L4之長度： 特定長度）之範圍之角部側區域13、及夾持於兩角部側區 域13間之中央側區域14，角部側區域13之端面τ係表面粗 146464.doc 14 201115264 度Ra為O.i nm之鏡面，中央側區域14係粗面。 又’該光罩基底用基板10之側面12具有倒角面C，及夾 於兩倒角面C間之端面T。又，端面T係具有一對長邊（長邊 L1或短邊L2)與一對短邊L3(短邊L3之長度：8.2 mm)之大 致矩形狀。又，中央側區域14係搬運基板時被把持之區 域。從基板之上面觀察該狀態，如圖1B所示，只對基板之 4個角隅部分（對應於角部側區域13之部分）鏡面研磨。又， 中央側區域14係表面粗度Ra為5 0 nm之粗面，侧面12之長 度（基板之厚度）為 10 mm 〇 於本發明中’大型光罩基底用基板1〇係指矩形基板或正 方形基板之一邊（較好的為各邊）在500 mm以上者。有關大 型光罩基底用基板10，現狀係存在短邊L2x長邊L1為500 mmx800 mm〜2140 mmx2460 mm之範圍中各種各樣之尺 寸’厚度（側面12之長度）為10〜15 mm。特別是若基板之長 邊L1之大小為800 mm以上時，則施加於端面之角部側區 域之力相當大’此外若為1200 mm以上，則施加於端面之 角部側區域之力變得非常大，如適用本申請案發明時之效 果非常大。 又，於本發明中，特定之鏡面係指表面粗度!^為〇 5 nm 以下之面，特定之粗面係指表面粗度Ra為5 〇 nm以上之 面。 如前所述’本實施形態係對構成端面T之角部側區域j 3 以表面粗度Ra 0.1 nm進行鏡面研磨，對中央側區域丨4以表 面粗度Ra 50 nm進行粗面研磨之光罩基底用基板1〇之一 146464.doc 15 201115264 例0 而後’對本實施形態之光罩基底用基板之製造方法連行 說明。該光罩基底用基板10之製造方法之鏡面研磨步驟 中’實施鏡面研磨端面之步驟後，實施研磨主表面之步 驟。 首先’使用圖2，對鏡面研磨端面之步驟進行說明。圖2 係用於說明鏡面研磨端面之方法之圖。如同圖所示，使用 杯型刷子21對角部側區域13 (同圖中斜線部）進行鏡面研 磨。然並非局限於此，只要為可鏡面研磨角部側區域1 3之 研磨方法，亦可使用其他任何研磨方法。 而後，使用圖3A、圖3B，對鏡面研磨主表面之步驟進 行說明。圖3係用於說明本發明之主表面之研磨步驟之概 略圖，圖3A係顯示頂視圖，圖3B係顯示側視圖。如同圖 所示，基板10之端面T係以載體31保持，基板1〇係以於上 下對向設置之上平盤32之研磨面34與下平盤33之研磨面35 之間，基板10之兩主表面丨丨與其等相接之方式夾持。之 後，使上下平盤32、33以相對於上下平盤之研磨面34、35 垂直之上下平盤之垂直軸為旋轉軸〇 1、〇2分別旋轉之同 時，使基板10之自轉軸03相對於下平盤之旋轉軸〇2平行 偏〜，且基板1〇之局部設定成位於下平盤之旋轉軸〇2上， 使基板經由使載體31旋轉而自轉。利用上下平盤之研磨面 34、35與基板之兩主表面丨丨彼此一邊接觸一邊相對性移 動’而研磨基板之兩主表面u。研磨步驟日夺，施加於基板 10之兩主表面U之壓力為100 g/cm2。 146464.doc •16· 201115264 又’可複數次進行如此之主表面11之研磨步驟，亦可進 行内容分別不同之主表面11之研磨步驟。例如，亦可為首 先將包含硬質拋光材料之研磨布用於研磨面34、35進行第 1研磨步驟，之後，將包含軟質拋光材料之研磨布用於研 磨面34、35進行第2研磨步驟者。如此，藉由複數次重覆 主表面11之研磨步驟，可製造具有更高平坦度之光罩基底 用基板10，令人滿意。 對於研磨步驟結束之基板1〇，進行特定之洗淨步驟後， 進行缺陷檢查’結果於基板主表面檢測出表面缺陷之基板 之發生率可降低至3 %左右’檢測出顆粒之發生率亦可降 低至5。/。左右’可達成非常高之成品率。 於本實施形態之光罩基底用基板1〇及光罩基底用基板1〇 之製造方法中’因只對端面T之4隅側鏡面研磨，故可防止 玻璃碎屑之發生或脫落，又可防止顆粒之附著或脫落。其 結果，可使光罩基底用基板1〇之研磨成品率、洗淨成品率 提高。 又，藉由粗面研磨端面T之中央側區域丨4，可獲得以下 效果。 (1) 可Μ短用於基板端面之鏡面研磨之加工時間。 (2) 利用人手進行處理之情形，可基本無問題地進行。 (實施形態2) 本實施形態中，長邊L12長度為122〇 mm，短邊L2之長 度為1400 mm，短邊L3之長度為i〇.6mm，邊以之長度為 150 mm，基板之厚度為丨3 mm，角部側區域丨3之表面粗度 146464.doc 201115264BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for a reticle substrate, and more particularly to a substrate for a large reticle substrate for manufacturing an FPD device. [Prior Art] In recent years, electronic devices, particularly color filters or TFT elements for semiconductor elements and liquid crystal displays, have been required to be further miniaturized with the rapid development of IT technology. One of the techniques supporting such microfabrication techniques is the use of lithography techniques known as photomasks for transfer reticles. This lithography technique forms a fine pattern on a ruthenium wafer by exposing an electromagnetic wave or a light wave of an exposure light source to a ruthenium wafer or the like with a resist film through a mask. The mask is usually formed by forming a film such as a light-shielding film on a light-transmitting substrate, and patterning the film using a lithography technique to form a film pattern as a transfer pattern. Further, in order to achieve the miniaturization of the pattern, it is also important to improve the quality of the base of the reticle used as the original for producing the reticle. In the photomask for semiconductors, in addition to the mirror polishing of the main surface of the substrate, the end faces formed on the periphery of the main surface of the substrate are also ground to form a specific mirror surface. However, the large-scale light army of the flat panel display (FPD: nat Panel Display), such as a liquid crystal display, an organic electroluminescence display, a t-face, and a reverse display, did not require the end face to be a mirror surface, and the end face was rough. When the end surface is a rough surface, the abrasive or the glass component adhering to the end surface cannot be completely removed by washing, and after the cleaning, the dirt is peeled off from the other surface and adhered to the main surface of the substrate. Or the film or resist film formed on the main surface becomes the cause of the 146464.doc 201115264 particle, which is the cause of the low yield. Fig. 4 is a perspective view showing a substrate for a large reticle base. The large-sized reticle base substrate 10 has two main surfaces 11 and four end faces T in the morning. In order to solve the problem of causing deterioration of the aforementioned yield, it is conceivable to form the end surface T of the large-sized mask base substrate 10 as a mirror surface. However, since the large-sized reticle base substrate 10 was originally developed, the processing of the large-sized reticle substrate 10 was difficult to mechanize, so that the end surface T was gripped by a human hand. In this case, when the end surface τ is processed, the handle sleeve and the large-sized mask base substrate 10 are slipped, so that the problem of the large-sized mask base substrate 1 cannot be prevented. In order to solve the above-mentioned problems, for a large-sized substrate for exposure, for example, it has been proposed by the manufacturer to make the end surface have a surface roughness when the substrate is wet, and the surface roughness Ra of the end surface is specifically 〇〇. In the case of the surface roughness Ra of the end surface, for example, 〇. 〇3 to 0.3 μηη (Japanese Patent Laid-Open Publication No. 2005-300566 (Patent Document 2) 。 。 。 。 。 。 。 。 。 。 。 。 。 。 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 2005 The large-sized substrate for exposure described in Patent Documents 1 and 2, when applied to the substrate 146464.doc 201115264, a large-sized photomask for FPD, etc., has a wide transfer line width and is attached to minute particles. Other problems mentioned above are more important in the adverse effects caused by the reticle base. ^ However, even after the large reticle' transfer pattern line width is progressing toward miniaturization, the influence of particles is hard to be ignored. With the increase in the size of FpD and the efficiency of FPD manufacturing, the size of the mask base has also progressed. Accompanied by the fact that the rough surface (non-mirror-polished) of the surface of the substrate has been applied to the entire circumference of the substrate or the end surface T The surface roughness!^ is about 〇3 to 〇4 μηι (Special: Documents 1, 2) 'The occurrence of glass debris from the end face of the substrate polishing is increased compared with the prior art, which has become a problem. The present invention has been made to solve the above problems, and an object of the present invention is to provide a substrate for a reticle base which can suppress generation of particles such as glass chips and abrasive grains from the end surface during polishing, and granules are produced. The incidence of surface defects in phase #. The inventors have analyzed the following cases. Fig. 5A to circle 5C are for explaining the occurrence of glass chips, and Fig. 5 is for showing the grinding of the main surface (the main surface is rotated right) Fig. 56 is a top view showing a state in which the main surface is polished (the main surface is rotated leftward), and Fig. 5C is a side view of the main surface and a side view of the carrier when it is ground. Substrate 1〇 by carrier 31 In a state where the substrate holding portion 31a is held, the carrier 31 is coaxially rotated with the rotating substrate, and the end faces of the substrate holding portion 3丨& are pressed, and the substrate 1〇 is rotated on the upper and lower flat plates. x, the main surface 11' of the two sides of the polishing substrate 1 is between the flat disk 32 having the polishing surface 34 and the flat disk 33 having the polishing surface, and the substrate is sandwiched by a specific pressure. .doc 201115264 ^The side surface T of the substrate holding portion 31a of the carrier 31 is pressed by the substrate 1 被 which is sandwiched between the two grinding surfaces of the frictional force, and the end surface T is pressed A large force is applied. Further, since the center of the substrate is rotated about the axis, the end face T does not exert the same force on the entire surface, and the substrate half is rotated toward the % line 11a by one half of the direction side 4, for example, the substrate 1 is not made as shown in FIG. 5A. In the case of clockwise rotation, almost all of the force is applied to the region τ of the end face τ. Further, even in the same area training, the load is gradually increased from the vicinity of the corner portion p where the end faces of the substrate symmetry line are in contact with each other. Further, when the substrate 1 is rotated counterclockwise, as shown in Fig. 5B, this time, it will become a load-carrying cloth having the same tendency in the region of the end surface τ. Since the polishing of the same substrate i , is performed both clockwise and counterclockwise, a load is applied to both the regions T1 and D2. Therefore, in the polishing of the main surface 11 of the substrate 10, a specific length region from the corner portion P of the region T1 and the region T2 (that is, a specific length from the corner portion ρ of the substrate of each end surface τ along the side of the main surface) The area), exerts a very large force. Further, in order to grind the main surface 11, the upper flat disk 32 and the lower flat disk 33 are coaxially rotated together. When the rotation directions of the upper and lower flat plates 32 and 33 are different from the rotation direction of the substrate 1 ,, the substrate 10 is rotated against the rotation direction of the polishing surfaces 34 and 35 having a high frictional force in contact under pressure. A stronger force is applied from a region of a specific length from the corner of the area and the corner of the area Τ2. Even in the case where the main surface of the large-sized mask base substrate 10 is polished on both sides, the pressure per unit area applied to the substrate 10 by the upper flat disk 32 and the lower flat disk 33 is the same as the glass substrate for the LSI photomask substrate. The pressure applied to both sides of the main surface is the same. That is, because the area of the large surface of the large-scale mask is 146464.doc 201115264, the area of the main surface 11 of the board 10 is much larger, so the load applied is also very large. On the other hand, the ratio of the length of the main surface side (long side) of the end surface to the thickness (the length of the short side) is larger than that of the LSI substrate, which is larger than the LSI substrate. In other words, the ratio of the area of the end surface of the large-sized reticle base substrate 10 to the main surface is small, and a larger force is applied than the substrate for the LSI reticle base. The ratio of the area of the end face to the main surface is more remarkable even if the size is increased and the thickness is not so thick. The glass crumb is the case where rough grinding (non-mirror grinding) is performed on the entire surface of the end face or when the surface roughness is 1 〇 3 〇 4 μπι (Patent Documents 1 and 2). Occurs when the convex portion of the surface is peeled off due to a strong force applied to the end surface τ. From the above, the inventors of the present invention have concluded that the size of the substrate for the large-sized reticle base has progressed toward a large size, so that it is pressed by the side wall of the substrate holding portion 3U of the carrier 31 during the double-side polishing. The force applied from the corner portion p of the substrate of each end face T in a certain length along the side of the main surface continues to increase, so that the incidence of glass debris also increases. Further, in the center side region of the end surface T, the incidence of the glass chip due to the rough surface of the substrate is also obtained, and the enlargement of the substrate size hardly affects it, and the inventors have It has been found that by making the portion of the central side region of each end face a rough surface, a region having a specific length from the corner portion of the substrate along the side of the main surface is a mirror surface having a surface roughness of 0.5 nm or less, thereby suppressing glass debris. This occurs and greatly suppresses the incidence of surface defects (scars) on the main surface of the substrate. In the present invention, at least the corner side region near the 4隅 side of the end face is subjected to the mirror polishing specified in the present application, and the rough side grinding is performed on the central side of the I46464.doc 201115264 in the center side of the end face T, The following two reasons. (1) The substrate 10' for the large-sized reticle base which is not mirror-polished to the end surface T is used to suppress the generation of glass chips or the dust of the abrasive residue, thereby implementing countermeasures against surface defects or measures for dust generation. (2) Shorten the processing time of the substrate. Compared with the case where the mirror-finished end face τ is comprehensive, the processing time of the end face grinding can be shortened. As a result, the cost of processing can be reduced. In the manufacturing step of the large reticle substrate, the surface of the substrate can be suppressed by the grinding step of the mirror surface grinding of the present application and then applied to the main surface 11 to suppress the occurrence of the glass debris and the accompanying surface. The effect of a low defect rate. Further, it is also possible to obtain an effect of reducing the occurrence of particles such as polishing residues. As a result of the test by the inventors and the like, it has been confirmed that the mirror polishing specified in the present application is carried out only in the vicinity of 4 Å of the substrate which is a portion of the polishing carrier which is strongly bonded to the substrate, and the effect can be sufficiently obtained. Means for Solving the Problems The present invention has the following constitution. (Configuration 1) A substrate for a reticle base, which is a thin plate composed of two main surfaces and four end faces, and has a chamfered surface between the end surface and the main surface, and is characterized in that: The length of one side of the surface system is 5 mm or more; the end surface includes two corner side regions of a region of a specific length ranging from a corner portion where the adjacent end faces meet each other along the main surface side, and is sandwiched between the two The central side region between the corner side regions; 146464.doc 201115264 The surface roughness of the end surface of the corner side region is a mirror surface of 5 nm or less; the central side region is a rough surface. (Aspect 2) The substrate for a mask base according to the first aspect, wherein the central side region has a surface roughness Ra of 5 〇 nm or more. (Structure 3) The substrate for a mask base according to the first or second aspect, wherein the specific length is 1 mm or more. (Structure 4) The substrate for a mask base according to the first or second aspect, wherein a length of one side of the main surface is 1000 mm or more, and the specific length is 1 50 mm or more. The reticle base substrate according to any one of the first to fourth aspect, wherein the central side region includes a region to be held when the substrate is transported. (Attachment 6) The substrate for a reticle base according to any one of the above 1 to 4, which is used for manufacturing a reticle base of a flat display. (Structure 7) A reticle substrate having a film on a main surface of a substrate for a reticle substrate which is recorded in any one of 丨 to 5. The present invention is described in detail with respect to the main surface of the substrate for a mask base according to any one of the items (1). The present invention will be described in detail below. The substrate is a thin plate formed by two main surfaces and four ends in the front surface and having an angle between the end surface and the main surface, wherein the length of one side of the main surface is 5 mm. The above-mentioned end face includes two corner side regions of a region of a specific length ranging from a corner portion where the adjacent end faces are in contact with each other along the main surface of J46464.doc 201115264, and a region sandwiching between the two corner portions The central side region; the surface roughness Ra of the end surface of the corner side region is a mirror surface of 5 nm or less; the central side region of the moon J is a rough surface (constitution 1). The substrate for the reticle substrate of the present invention is The thin plate composed of the two main surfaces and the four end faces in the table has a chamfered surface between the end faces and the main surface (constitution 1). For example, in the present invention, as shown in FIG. 1C, the two main faces are shown. Surface ii 彳 4 $ and the surface τ Further, in the substrate for a reticle base of the present invention, the length of one side of the main surface U is 500 mm or more (constitution 1). For example, in the present invention As shown in Fig. 1B, the length of the short side is 5 mm or more. Further, in the substrate for a reticle base of the present invention, the end surface includes a corner portion which is adjacent to each other from the end surface, and is specified along the side of the main surface. The corner portion side region of the length range and the center side region sandwiched between the corner portion side regions (constitution 1). As in the present invention, 'the end surface τ includes the angle from the end surface τ to each other as shown in FIG. The corner portion side region 13 having a specific length (the length of the side L4) along the long side L1 direction of the main surface 11 and the center side region 14 sandwiched between the corner portion side regions 13. Further, the mask of the present invention In the substrate for a substrate, the surface roughness Ra of the end surface of the corner-side region is a mirror surface of 0 5 nm or less (constitution 1). 146464.doc • 11- 201115264 For example, in the present invention, as shown in FIG. The surface roughness Ra of the end surface τ of the side region 13 is a mirror surface of 0.5 nm or less. Further, the corner side region When the surface roughness Ra of the surface T is less than or equal to 3 nm, the incidence of the particles can be further reduced, which is more preferable. Further, in the substrate for a reticle base of the present invention, the central side region is a rough surface (constitution 1) For example, in the present invention, as shown in FIG. 1A, the center side region 14 is a rough surface. Thus, in the present invention, in a substrate for a reticle substrate having a specific size (the side length is 5 〇〇 mm or more), The corner side regions of the four end faces are mirror-finished, and the central side regions of the four end faces are rough faces. This is used to solve the problem of handleability and glass chipping together, that is, "the partial region of the central side region becomes The rough surface can solve the problem of handling. Further, since the corner-side region where the force applied from the side wall of the substrate holding portion 3 la of the carrier 31 is large is formed into a mirror surface, the problem of glass chips is also solved. Further, in the substrate for a reticle base of the present invention, the central side region is preferably a rough surface having a surface roughness Ra of 50 nm or more (constitution 2). This is because the problem of processing can be solved more effectively. Further, the upper limit of the surface roughness Ra of the central side region of the rough surface is preferably 4 〇〇 nm. If the surface roughness is thicker than the 4 〇〇 claw, the problem of the incidence of the granules will be significant. Further, when the surface roughness of the center side of the rough surface is 300 nm or less, the incidence of particles can be reduced. The surface roughness is preferably 2 〇〇 nm or less. Further, in the base of the reticle base of the present invention, it is preferable that the bronchial length is not more than mm (constitution 3). This is because the problem of glass debris can be solved more effectively. Further, in the substrate for a reticle base of the present invention, the length of one side of the main surface is preferably 1000 mm or more, and the specific length is preferably 150 mm or more (construction 4). This is because the length of one side of the main surface is 1 〇〇〇mrn or more. 'The area where the force received from the side wall of the substrate holding portion 3 13 of the carrier 31 is widened', if the specific length is 150 mm. In the above, the problem of handleability and glass chipping can be more effectively solved. Further, if the specific length is 2 mm or more, the incidence of glass chips and particles can be further reduced, which is preferable. Further, if there is no problem in handling property or a problem of substrate detection, it is preferable to set the length of the feature to be 300 mm or more to further reduce the incidence of glass chips and particles. Further, in the substrate for a reticle base of the present invention, the central side region preferably includes a region (constitution 5) that is held when the substrate is transported. This is because the central side region contains the region that is held when the substrate is transported, and the problem of handleability can be more effectively solved. Further, a defect inspection device for a large reticle base, a reticle inspection device for inspecting a transfer pattern formed on a large reticle, an exposure drawing device for exposing a transfer pattern to a resist film formed on a reticle base, and an exposure device There is a case where light is irradiated on the end face T to detect the presence or absence of a large reticle base or a large reticle on the stage. In such a case, it is effective to set the center side area as a rough surface. Further, the substrate for a photomask substrate of the present invention can also be used in the manufacture of a photomask substrate for a flat panel display (Configuration 6). Further, the substrate for a reticle base of the present invention may have a film (configuration 7) on the main surface. Further, the substrate for a reticle base of the present invention may have a film pattern on the main surface (configuration 8). Advantageous Effects of Invention In the substrate for a reticle base of the present invention, in the polishing step of the main surface of the substrate, the mirror polishing can be performed on the corner portion near the substrate 4 非常 which is applied very strongly to the end surface, thereby greatly reducing the glass. When the incidence of debris is suppressed and the surface defect generation rate is lower than the 'grinding step' of the main surface of the substrate, the processing can be provided by making the central side region of the substrate which is relatively less strongly applied to the rough side. It is easy to accept the substrate for the mask base when it is processed. [Embodiment] (Embodiment 1) First, the structure of a substrate for a reticle base of the present invention will be described with reference to Figs. 1A to 1C and Fig. 2 . BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the structure of a substrate for a reticle base of the present invention, Fig. 1A is a side view of a substrate for a reticle base, Fig. 1B is a top view, and Fig. 1C is a partially enlarged view of a side surface. As shown in FIG. 1c, the mask base substrate 10 of the present embodiment has a thin plate composed of two main surfaces 丨丨 and four end faces T, and has a chamfered surface C between the end surface τ and the main surface 丨丨. . As shown in FIG. 1B, the main surface π has a substantially rectangular shape of a pair of long sides [1 (length of long side 1 : 800 mm) and pair of short side L2 (length of short side L2: 5 mm) . As shown in FIG. 1A and FIG. 1C, the end surface T includes a corner side region 13 and a clip in a range of 100 mm (the length of the side L4: a specific length) from the corner portion where the end faces are in contact with each other along the side of the main surface 11. The central side region 14 between the two corner side regions 13 and the end surface τ of the corner side region 13 have a surface roughness of 146464.doc 14 201115264 degrees Ra is a mirror surface of Oi nm, and the central side region 14 is a rough surface. Further, the side surface 12 of the mask base substrate 10 has a chamfered surface C and an end surface T sandwiched between the chamfered surfaces C. Further, the end face T has a substantially rectangular shape of a pair of long sides (long side L1 or short side L2) and a pair of short sides L3 (length of short side L3: 8.2 mm). Further, the center side region 14 is a region to be gripped when the substrate is transported. This state is observed from the upper surface of the substrate, and as shown in Fig. 1B, only the four corner portions of the substrate (corresponding to the portion of the corner side region 13) are mirror-polished. Further, the central side region 14 is a rough surface having a surface roughness Ra of 50 nm, and the length of the side surface 12 (thickness of the substrate) is 10 mm. In the present invention, the substrate 1 for a large-sized mask base is a rectangular substrate or One side of the square substrate (preferably each side) is 500 mm or more. Regarding the large-sized reticle base substrate 10, the short-side L2x long side L1 is in the range of 500 mm x 800 mm to 2140 mm x 2460 mm, and the various thicknesses (the length of the side surface 12) are 10 to 15 mm. In particular, when the size of the long side L1 of the substrate is 800 mm or more, the force applied to the corner portion side region of the end surface is relatively large, and when the thickness is 1200 mm or more, the force applied to the corner portion side region of the end surface becomes Very large, if the invention of the present application is applied, the effect is very large. Further, in the present invention, the specific mirror surface means a surface roughness! ^ is a surface of 〇 5 nm or less, and a specific rough surface means a surface roughness Ra of 5 〇 nm or more. As described above, in the present embodiment, the corner portion side region j 3 constituting the end surface T is mirror-polished at a surface roughness Ra 0.1 nm, and the center side region 丨4 is rough-surface-grounded with a surface roughness Ra 50 nm. One of the substrates for the cover base 1 146464.doc 15 201115264 Example 0 Next, the method of manufacturing the substrate for a mask base of the present embodiment will be described in parallel. In the mirror polishing step of the method for manufacturing the mask base substrate 10, the step of polishing the main surface is carried out after the step of performing the mirror-polished end surface. First, the procedure of mirror-polished the end face will be described using Fig. 2 . Figure 2 is a diagram for explaining the method of mirror-finishing the end face. As shown in the figure, the corner portion 13 (the oblique portion in the same figure) is mirror-finished using the cup brush 21. However, it is not limited thereto, and any other polishing method may be used as long as it is a method of polishing the mirror-polished corner side region 13 . Then, the steps of mirror-polishing the main surface will be described using Figs. 3A and 3B. Fig. 3 is a schematic view for explaining the grinding step of the main surface of the present invention, Fig. 3A showing a top view, and Fig. 3B showing a side view. As shown in the figure, the end surface T of the substrate 10 is held by a carrier 31 which is disposed between the polishing surface 34 of the upper flat disk 32 and the polishing surface 35 of the lower flat disk 33, which are disposed oppositely above and below, and the substrate 10 The main surface is clamped in such a way as to be in contact with it. Thereafter, the upper and lower flat plates 32, 33 are rotated relative to the vertical axes of the upper and lower flat plates of the upper and lower flat plates, respectively, while the rotation axes 〇1 and 〇2 are rotated, respectively, so that the rotation axis 03 of the substrate 10 is relatively The rotation axis 2 of the lower plate is parallel-biased, and the portion of the substrate 1 is set to be located on the rotation axis 2 of the lower plate, so that the substrate rotates by rotating the carrier 31. The two main surfaces u of the substrate are polished by the polishing surfaces 34, 35 of the upper and lower flat plates and the two main surfaces of the substrate, while being in contact with each other while being oppositely moved. The grinding step was carried out, and the pressure applied to the two main surfaces U of the substrate 10 was 100 g/cm2. 146464.doc •16· 201115264 Further, the grinding step of the main surface 11 may be performed plural times, and the grinding step of the main surface 11 having different contents may be performed. For example, the first polishing step may be performed by first using a polishing cloth containing a hard polishing material on the polishing surfaces 34 and 35, and then applying a polishing cloth containing a soft polishing material to the polishing surfaces 34 and 35 for the second polishing step. . Thus, by repeating the grinding step of the main surface 11 a plurality of times, the substrate 10 for a mask base having higher flatness can be manufactured, which is satisfactory. After the specific cleaning step is performed on the substrate 1 after the polishing step, the defect inspection is performed. As a result, the incidence of the substrate on which the surface defect is detected on the main surface of the substrate can be reduced to about 3%. The incidence of the detected particles can also be detected. Reduce to 5. /. A good yield can be achieved by the left and right. In the method of manufacturing the mask base substrate 1 and the mask base substrate 1 of the present embodiment, the mirror surface of the end surface T is only mirror-polished, so that the occurrence or breakage of the glass chips can be prevented. Prevent particles from sticking or falling off. As a result, the polishing yield and the cleaning yield of the substrate 1 for the mask base can be improved. Further, by rough grinding the center side region 丨4 of the end face T, the following effects can be obtained. (1) The processing time for mirror polishing of the end face of the substrate can be shortened. (2) The situation of handling by hand can be carried out substantially without problems. (Embodiment 2) In the present embodiment, the length of the long side L12 is 122 mm, the length of the short side L2 is 1400 mm, the length of the short side L3 is i〇.6 mm, the length of the side is 150 mm, and the thickness of the substrate丨3 mm, the surface roughness of the corner side area 丨3 is 146464.doc 201115264
Ra為0.05 nm，中央側區域14之表面粗度Ra為500 nm(表面 粗度Ra 500 nm之表面，目視為霧狀者），中央側區域14係 包含在曝光裝置之光罩載臺52載置基板時，照射用於檢測 光罩之檢測光之區域者。又，處理並非由人手而係使用機 械進行。對於其他構成及光罩基底用基板10之製造方法， 因與前述實施形態1相同，故此處省略說明。 對於研磨步驟結束之基板1 〇，進行特定之洗淨步驟後， 進行缺陷檢查，結果於基板主表面檢測出表面缺陷之基板 之發生率可降低至3%左右，顆粒檢測之發生率亦可降低 至5%左右，可達成非常高之成品率。 於本實施形態之光罩基底用基板10及光罩基底用基板1〇 之製造方法中’可獲得與前述實施形態1相同之效果。 (比較例1) 於本比較例，係使尺寸為500 mmx800 mm，厚度為1〇 mm之光罩基底用基板10之端面全面為表面粗度Ra 5〇 nm 之粗面0 之後’對光罩基底用基板1〇之兩主表面U，以與前述實 施形態相同之研磨方法實施鏡面研磨。 對於研磨步驟結束之基板1 〇，進行特定之洗淨步驟後， 進行缺陷檢查’結果於基板主表面檢測出表面缺陷之基板 之發生率高至20%左右，檢測出顆粒之發生率亦高至3〇% 左右，為低成品率。 又，雖嘗試以穿戴有處理用手套之手進行處理，但處理 用手套與大型光罩基底用基板10間非常滑溜而危險，判明 146464.doc •18· 201115264 缺乏實用性。 (比較例2) 於本比較例，係使尺寸為1220 mmxl4〇〇 mm，厚度為Η mm之光罩基底用基板10之端面全面為表面粗度Ra i〇nm 之鏡面。 之後，對光罩基底用基板1〇之兩主表面u，以與前述實 施形態相同之研磨方法鏡面研磨。 對於研磨步驟結束之基板10，進行特定之洗淨步驟後， 進行缺陷檢查，結果於基板主表面檢測出表面缺陷之基板 之發生率尚至30%左右，檢測出顆粒之發生率亦高至4〇% 左右’為低成品率。 又，雖嘗試以穿戴有處理用手套之手進行處理，但基板 10之重量非常之重，處理用手套與大型光罩基底用基板1〇 間滑溜，無法把持大型光罩基底用基板1〇。 又，於前述實施形態中，雖中央側區域14之整體為粗 面，但在尺寸相對較小之大型光罩基底用基板之情形下， 用於進行處理之把持區域為特定時，可將不包含中央側區 域14之該等特定區域之區域之端面τ亦形成為與角部側區 域相同程度或其以上之表面粗度之鏡面。此外，以使用機 械或夾具之處理使基板移動之情形，若因前述基板檢測之 關係而有必要設為粗面之中央側區域14之特定區域若可預 先決定，則不受限於基板之大小，亦可為僅有中央側區域 14之有必要設為粗面之區域為前述表面粗度之粗面，除此 之外之中央側區域14為與角部側區域相同程度或其以上之 146464.doc •19· 201115264 表面粗度之鏡面即可。又，於中央側區域14令，為進一步 降低破璃碎屑之發生率或研磨劍之固著引起之顆粒之發生 率，亦可為從中央側區域14之基板對稱線向兩側之角部側 區域每隔特定距離階段性地減小表面粗度之構成。 又光罩基底用基板ίο之基板形狀，並非局限於矩形， 亦可為主表面η之一邊為500 mm以上之正方形。 又本發明不受以上實施形態之限定’又，在不脫離本 發明之要旨之範圍内可進行各種各樣之變更。 【圖式簡單說明】 圖1A係顯示本發明之光罩基底用基板之構造之側視圖； 圖係顯示本發明之光罩基底用基板之構造之頂視圖； 圖1C係顯示本發明之光罩基底用基板之構造之側面之局 部放大圖； 圖2係用於說明鏡面研磨端面之方法之圖； 圖3A係用於說明本發明之主表面之研磨步驟之概略之頂 視圖； 圖3B係用於說明本發明之主表面之研磨步驟之概略之側 視圖； 圖4係顯示大型光罩基底用基板之立體圖； 圖5A係用於說明玻璃碎屑之發生之圖，顯示主表面之研 磨時（主表面右旋轉）之狀態之頂視圖； 圖5B係用於說明玻璃碎屑之發生之圖，顯示主表面之研 磨時（主表面左旋轉）之狀態之頂視圖；及 圖5C係用於說明玻璃碎屑之發生之圖，顯示主表面之研 146464.doc •20· 201115264 磨時之端面及載體之側視圖。 【主要元件符號說明】 10 光罩基底用基板 11 主表面 11a 基板對稱線 12 側面 13 角部側區域 14 中央侧區域 21 刷子 31 載體 31a 基板保持部 32 上平盤 33 下平盤 34 ' 35 研磨面 C 倒角面 LI 長邊 L2 短邊 L3 短邊 ΟΙ、02 旋轉軸 03 自轉軸 P 角部 T 端面 146464.doc •21 ·The Ra is 0.05 nm, the surface roughness Ra of the central side region 14 is 500 nm (the surface having a surface roughness of Ra 500 nm, which is regarded as a mist), and the central side region 14 is contained in the photomask stage 52 of the exposure device. When the substrate is placed, the area for detecting the detection light of the photomask is irradiated. Moreover, the processing is not performed by a human hand but by a machine. The manufacturing method of the other configuration and the substrate 10 for the mask base is the same as that of the first embodiment, and thus the description thereof will be omitted. After the specific cleaning step is performed on the substrate 1 after the polishing step, the defect inspection is performed, and as a result, the incidence of the substrate on which the surface defect is detected on the main surface of the substrate can be reduced to about 3%, and the incidence of particle detection can be lowered. To about 5%, a very high yield can be achieved. In the method of manufacturing the mask base substrate 10 and the mask base substrate 1A of the present embodiment, the same effects as those of the first embodiment described above can be obtained. (Comparative Example 1) In the present comparative example, the end face of the substrate 10 for a reticle substrate having a size of 500 mm x 800 mm and a thickness of 1 mm was used as a rough surface of the surface roughness Ra 5 〇 nm. The two main surfaces U of the substrate substrate 1 are mirror-polished in the same polishing method as in the above embodiment. After the specific cleaning step is performed on the substrate 1 after the polishing step, the defect inspection is performed. As a result, the incidence of the substrate on which the surface defect is detected on the main surface of the substrate is as high as about 20%, and the incidence of the detected particles is also high. About 3%, it is low yield. Further, although it was attempted to handle the hand with the glove for processing, the handle glove and the large-sized mask base substrate 10 were very slippery and dangerous, and it was found that 146464.doc •18·201115264 lacked practicality. (Comparative Example 2) In the present comparative example, the end surface of the substrate 10 for a mask base having a size of 1220 mm x 14 mm and having a thickness of Η mm was a mirror surface having a surface roughness Ra i 〇 nm. Thereafter, the two main surfaces u of the substrate 1 for the mask base are mirror-polished by the same polishing method as in the above embodiment. After the specific cleaning step is performed on the substrate 10 after the polishing step, the defect inspection is performed, and as a result, the incidence of the substrate on which the surface defect is detected on the main surface of the substrate is about 30%, and the incidence of the detected particles is as high as 4 〇% around 'is a low yield. In addition, the weight of the substrate 10 is extremely heavy, and the processing glove and the large-sized mask base substrate 1 are slippery, and the large-sized mask base substrate 1 cannot be held. Further, in the above-described embodiment, the entire center side region 14 is a rough surface. However, in the case of a large-sized photomask base substrate having a relatively small size, when the holding region for processing is specific, it may be The end surface τ of the region including the specific regions of the central side region 14 is also formed as a mirror surface having the same or a greater surface roughness as the corner side region. Further, in the case where the substrate is moved by the processing using a machine or a jig, if the specific region of the center side region 14 of the rough surface is determined in advance due to the relationship between the substrate detection, it is not limited to the size of the substrate. Further, it is also possible that the region having the rough side only in the center side region 14 is the rough surface of the surface roughness, and the center side region 14 is the same level as the corner side region or above 146464. .doc •19· 201115264 The surface roughness can be mirrored. Further, in the central side region 14, in order to further reduce the incidence of broken glass chips or the incidence of particles caused by the fixation of the grinding sword, the symmetry of the substrate from the central side region 14 may be toward the corners of both sides. The side regions periodically reduce the composition of the surface roughness at specific distances. Further, the substrate shape of the substrate for the mask base is not limited to a rectangular shape, and may be a square having a side of the main surface η of 500 mm or more. Further, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit and scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a side view showing the structure of a substrate for a mask base of the present invention; Fig. 1C is a top view showing the structure of a substrate for a mask base of the present invention; FIG. 2 is a view for explaining a method of mirror-finishing an end surface; FIG. 3A is a top view for explaining a grinding step of a main surface of the present invention; FIG. FIG. 4 is a perspective view showing a substrate for a large reticle base; FIG. 5A is a view for explaining the occurrence of glass swarf, showing the grinding of the main surface ( FIG. 5B is a top view showing the occurrence of glass debris, showing a top view of the state of the main surface during polishing (the main surface is rotated leftward); and FIG. 5C is for explaining The diagram of the occurrence of glass debris shows the side surface of the main surface 146464.doc •20· 201115264 The end face of the grinding and the side view of the carrier. [Main component symbol description] 10 Photomask base substrate 11 Main surface 11a Substrate symmetry line 12 Side surface 13 Corner side region 14 Center side region 21 Brush 31 Carrier 31a Substrate holding portion 32 Upper flat plate 33 Lower flat plate 34 ' 35 Polished surface C chamfered surface LI long side L2 short side L3 short side ΟΙ, 02 rotating shaft 03 rotation axis P corner T end face 146464.doc • 21 ·