200823969 九、發明說明：200823969 IX. Description of invention:
技術領域 本發明係有關於一種電子束曝光裴置及電子束曝光方 5法’特別是有關於一種利用可變矩形開口及可變形束 (Character Projection)圖案，使電子束形狀及大小可產生變 化之電子束曝光裝置及電子束曝光方法。 【先前ϋ 發明背景 近幾年來，電子束曝光裝置中，為提升生產效率，於 光罩上準備有可變矩形開口或多數的光罩圖案，藉由電子 束偏折，選擇可變矩形開口或多數的光罩圖案於樣品上進 行轉印曝光。 15 此類曝光裝置係用以進行可變形束曝光的電子束曝光 裝置。可變形束曝光係藉由電子束偏折，將電子束照射至 從配置於光罩上的多數個圖案選出之其中一個圖案領域， 使電子束截面形成圖案形狀，接著，藉後段的偏折器使通 過光罩的電子束偏折回來，並依照電子光學系統所決定之 一定的縮小率縮小後，轉印於樣品上。 20 可變形束曝光中，如事先於光罩上備妥使用率高的圖 案的話，跟僅具有可變矩形開口者比起來，可大幅減少必 要的曝光射擊數，提升生產效率。 另-方面，若採用可變矩形開口及可變形束圖案進行 電子束曝光，電子束之尺寸會隨著每次射擊而有所不同， 造成電子束失焦，使電子束發生模糊現象。例如，以小尺 25 200823969 - 彳電子束於樣品表面完成對焦時，如以大尺寸電子束… 、 #光，則電子束的總電流會增大，造成焦距延長，使，了 表面發生電子束模糊現象。 纟防止諸如此_電子束失线況發生，現已提出有 5⑯可變矩形開口之面積算出每次射擊時流人再聚焦線圈之 電流並修正的方法。專利文獻丨中揭示與矩形電子束之尺寸 一致，以控制聚焦線圈的方法。 馨 又，專利文獻2中揭示在進行電子束的再聚焦之際，測 定電子束軸之偏位並修正的方法。 10 如上述，使用可變矩形開口及可變形束圖案時，可藉 由使電子束之焦點於每次射擊時進行移動，防止電子束失 、 焦。 - 具體而言，設置再聚焦線圈，將與整形後之電子束截 面積成正比的電流量流入再聚焦線圈後，調整電子束的焦 15 點。例如，電子束尺寸大時，將與電子束截面積成比例的 φ 更強電流流入再聚焦線圈，以加強電子束的聚焦作用。 不過，實行再聚焦需耗費時間，儘管實施可變形束曝 光，仍會產生無法提升曝光效率的問題。 舉例來說，儘管整形電子束僅需耗費5〇ns左右的時 20間，但實行再聚焦時，直到預定電流流入再聚焦線圈且電 流變安定為止，卻得耗費300ns左右的時間，造成等待曝光 時間變得冗長。 專利文獻1 :特開昭56-94740號公報 專利文獻2 ··特開昭58-121625號公報 6 25 200823969 【發明内容】 、 發明開示 • 有鑑於先前技術之課題，本發明之目的係提供一種於 可改虼電子束形狀及大小之電子束曝光中，得以縮短再聚 5焦時間且提升生產效率的電子束曝光裝置及電子束曝光方 " 法。 上述課題係可藉由一種電子束曝光裝置解決，該電子 φ 束曝光襞置之特徵在於包含有電子槍、整形機構、投影透 鏡、再聚焦鏡及控制機構。該電子槍係用以放射電子束者， 且該整形機構係具有用以整形前述電子束之開口者，而該 投影透鏡係用以使前述電子束於樣品面上成像者，且該再 聚焦鏡係設置於前述投影透鏡上方，由用以修正電子束之 纟點的多極靜電透鏡所形成者，而該控制機構係可於前述 再聚焦鏡施加因應業經前述整形機構整形之前述電子束之 15截面積的電壓者。 Φ 此型態之電子束曝光裝置中，前述再聚焦鏡係可於前 述電子束之電子束軸方向具有3段4極靜電電極者，且前述3 段4極靜電電極中，第1段及第3段電極長度可相同，第2段 龟極長度可為第1段電極長度的2倍。又，施加於前述第工 • 2〇段、第2段及第3段之x方向電極的電壓與施加於y方向電極 的電壓係可為極性相反者，施加於前述第丨段之义方向電極 的電壓與施加於前述第2段之X方向電極的電壓係可為極性 相反者，施加於前述第1段之X方向電極的電壓與施加於前 述第3段之X方向電極的電壓係可為極性相同者，施加於前 25述第1段之y方向電極的電壓與施加於前述第3段之y方向電 200823969 ~ 極的電壓係可為極性相同者。 ‘ 本發明中，為進行用以調整電子束焦點之再聚焦，裝 • 設有以靜電電極構成的電子束之再聚焦鏡。該再聚焦鏡係 ^ 由3段4極透鏡重疊而構成，俾使通過其間的電子束進行聚 5焦者。施加於構成再聚焦鏡之各電極的電壓係因應經整形 之電子束截面積以進行調整者。藉此，即使所照射之電子 束的電子量有所變化，亦可於樣品表面上進行對焦。而且， 馨由於使用靜電電極並藉由電壓調整電場，故可加快再聚焦 速度，且可提升曝光效率。 10 圖式簡單說明 第1圖係本發明之電子束曝光裝置的構造圖。 第2圖⑻、（b)係本發明之電子束曝紐置之再聚焦鏡 的構造圖。 第3圖係1灰4極靜電電極之電子偏折控制的說明圖。 15 第4圖係3段4極靜電電極之電子軌道的說明圖。 • 第5圖係再聚焦鏡之各電極之連接關係的表示圖。 第6圖係再聚焦電路的說明圖。 一 第7圖係再聚焦量的說明圖。 第8圖(a)〜(c)係計算再聚焦係數的說明圖（其1)。 2〇 冑9®係計算再聚焦係數的說關(其2)。 t實方包方式】 實施發明之最佳態樣 以下將參照圖式說明本發明之實施型態。 先"兒月电子束曝光裝置的構造。其次，說明用以 25進订电子束之再聚焦的再聚焦鏡。最後，說明電子束曝光 200823969 方法。 (電子束曝光裝置的構造） f1圖係本實施㈣之電子束曝光裝置的構造圖。 月】述私子束曝光裝置可大致區分成電子光學柱1〇〇及 5控制電子光學柱⑽各部的控制部扇。其中，電子光學柱 ⑻由電子束生成部13G、光罩偏折部⑽及基板偏折部15〇 構成，且其内部經減壓。 #電子束生成部U0中，從電子㈣i生成之電子束现於 1第1¾磁透鏡102處受到聚焦作用後，穿透電子束整形用光 10罩1〇3上的矩形開口職，使電子束四的截面整形成矩形。 之後，電子束EB藉光罩偏折部14〇上的第2電磁透鏡 1〇5成像於曝光光罩則上。接著，電子束的藉第丨、第2靜 電偏折器104、106偏折域形於曝光光罩11〇上的特定圖案 S，使其截面形狀整形成圖案8的形狀。 15 此外，曝光光罩110雖固定於光罩平台123上，但前述 光罩平台123可水平移動，若使用位於超過第〗、第2靜電偏 折1§ 104、106之偏折範圍（電子束偏折領域)部分的圖案s， 則可藉由移動光罩平台123，使前述圖案s移動至電子束偏 折領域内。 2〇 又’亦可配置使電子束可變化成預定形狀之開口部， 用以取代曝光光罩110。 配置於曝光光罩上下方的第3、第4電磁透鏡1〇8、lu， 可藉由調整其電流量，使電子束EB成像於基板W上。 通過曝光光罩110的電子束EB藉第3、第4靜電偏折器 25 112、113的偏折作用偏折回到光軸（電子束軸)C後，再藉由 200823969 第5電磁透鏡ii4縮小其尺寸。 光罩偏折部140設有第1、第2修正線圈1〇7、1〇9，藉由 珂述第1、第2修正線圈，可修正發生於第〗〜4靜電偏折器 104、106、112、113的電子束偏折分散現象。 5 之後，电子束EB通過構成基板偏折部150之遮蔽板115 上的開口 115a，且藉由再聚焦鏡128，因應電子束Εβ之截面 積進行焦點的調整後，再藉第1、第2投影用電磁透鏡116、 121投影至基板W上。藉此，曝光光罩11〇的圖案影像將以 例如1/10縮小率之預定縮小率，轉印至基板w上。 1〇 基板偏折部150設有第5靜電偏折器119及電磁偏折器 120’藉由前述偏折器119、12〇偏折電子束EB，將曝光光罩 110的圖案影像投影至基板w的預定位置。 又，基板偏折部150設有第3、第4修正線圈117、118， 用以修正電子束EB於基板w上的偏折分散現象。 15 基板W固定於可藉馬達等驅動部125水平移動的晶圓 平σ 124上，且經由移動晶圓平台124，得以對基板w的全 體面進行曝光。 另一方面，控制部200具有電子搶控制部202、電子光 學系統控制部203、光罩偏折控制部2〇4、光罩平台控制部 20 205、遮蔽控制部206、基板偏折控制部207、晶圓平台控制 部208及再聚焦控制部209。其中，電子搶控制部202控制電 子槍101，以控制電子束ΕΒ的加速電壓及電子束放射條件。 又，電子光學系統控制部203控制流入電磁透鏡1〇2、105、 108、1Η、114、116及121的電流量，以調節前述電磁透鏡 25構成之電子光學系統的倍率及焦點位置。遮蔽控制部206藉 10 200823969 由控制施加於遮蔽電極127的電壓，將開始曝光前即產生之 電子束EB偏折至遮蔽板115上，以防止電子束四於曝光前 照射至基板W上。 基板偏折控制部207藉由控制施加於第5靜電偏折器 5 n9的電壓及流入電磁偏折器120的電流量，使電子束£3偏 折至基板w的預定位置上。晶圓平台控制部2〇8調節驅動部 125的驅動量使基板…水平移動，以使電子束EB照射至基板 W的預期位置。 再ί^焦控制部209因應穿透曝光光罩11 〇且經整形之電 10子束ΕΒ<截面積，使必要電流供給至構成再聚焦鏡的各電 極0 上述各部202〜209可藉由工作站等的統合控制系統2〇1 予以統合控制。 (再聚焦鏡） 15 第2圖顯示本實施型態使用之再聚焦鏡的構造。第2(a) 圖顯示設置於投影用透鏡116、121之電子槍1〇1侧上方之再 聚焦鏡128的平面圖，且第2(b)圖顯示從正面觀察之再聚焦 鏡128的截面圖。 如第2圖所示，再聚焦鏡128係將使用4根靜電電極之4 20 極靜電透鏡於電子束轴方向（Ζ軸方向）以預定間隔重疊而 構成者。 4極靜電透鏡沿電子束照射方向，從靠近電子搶者算 起，分成第1段、第2段、第3段，並將第1段、第2段、第3 段的4極靜電透鏡分別標示為LSI、LS2、LS3。 25 4極靜電透鏡LSI由4根靜電電極Pli、P12、P13、P14 11 200823969 構成，且以電子束軸(z軸)為中心，等間隔地於χ軸方向及丫 軸方向各配置2根。例如，各電極長度以為…爪㈤。 4極靜電透鏡LS2由4根靜電電極p2i、P22、P23、P24 構成，且配置於LSI的下段。4極靜電透鏡[以的“艮電極於 5 Z軸方向與LSI的4根電極以預定間隔(^重疊配置，且該預 定間隔G1以5匪為例。4極靜電透鏡LS2的各電極長度[2為 4極靜電透鏡LSI的各電極長度L1的2倍。例如L1為l〇mm 時，L2則為20mm。 4極靜電透鏡LS3由4根靜電電極p3i、P32、P33、P34 1〇構成，且配置於LS2的下段。4極靜電透鏡LS3的4根電極於 Z軸方向與LS2的4根電極以預定間隔〇2重疊配置，且該預 定間隔G2以5mm為例。 4極靜電透鏡LS3的各電極長度乙3與LSI相同。 接著，說明藉由如此構成的再聚焦鏡可調整電子之焦 15點。首先，就1段4極靜電透鏡，說明通過其間後的電子偏 折量。 第3圖係表示1段4極靜電透鏡的平面圖。該透鏡的電位 分布 0 表示成 ¢ = A(x2— y2)/r。2。在此，Γ。二 2mm。 於Z軸方向通過其中之電子可於X軸方向及γ軸方向受 20 力前進。x = lmm 時，電場為 £(x 二 1) = -d 0 /dx = 40/9[V/mm]。在此，對通過離電子軸lmm處的電子於距離z 軸方向5000mm之位置時的偏光量進行討論。 假設，考慮對應電子通過平行平板間時的電子偏光 量。若忽略在平行平板兩端部之電場混亂，則在位於距離 電極之長度1處的偏折量D可用下列公式表示。 12 25 200823969 D=(lb/2d)x(Vd/V0) ...(i) 在此，b為平行平板的長度，Vd為施加於平板間的電 壓，V0為電子的入射電壓（以50kv為例）。 此公式中，2Vd/d係為電場E，。 公式⑴中，若 b = l〇[mm]、E = 4〇/9[v/叫、v〇 = 50000[v]、1=5000[mm]，則偏折距離D即為1 n卜p 亦即，偏折l[mm]即可使焦點位於電子束轴上，故藉由 調整施加於電極的電壓即可達到目的。如此一來，電子之 焦點即可精由1段4極透鏡進行調整。 因此，即使4極透鏡由多段構成時，亦可調整電子之焦 點。 弟4圖係3#又4極靜電電極之電子執道的說明圖。以第4 圖的z軸為電子束軸，圖中電子束的行進方向為由左往右前 進。 15 第4圖的X軸側表示X方向的電子束軌道Cry軸側表示y • 方向的電子束執道C2。如第4圖所示，若注意觀察x方向的 執迢G，則可發現第1段4極透鏡的作用為凸透鏡、第2段4 極透鏡的作用為凹透鏡、第3段4極透鏡的作用為凸透鏡。 再者，若注意觀察y方向的執道C2，則可發現第丨段4極透鏡 20的作用為凹透鏡、第2段4極透鏡的作用為凸透鏡、第3段4 極透鏡的作用為凹透鏡。而且，χ方向及向在射向最終 焦點Z2之入射角度上幾乎相同。因此，藉由使用前述3段4 極靜電電極，即可輕易進行焦點的調整。 藉由再聚焦控制部209施加預定電壓於如第2圖構成之 25再聚焦鏡的各電極，以使再聚焦鏡128全體產生足以進行再 200823969 ~ 聚焦的必要電場。在本實施型態中，將施加如第5圖所示之 ， 極性的電壓。第5圖簡易地並排顯示4極靜電透鏡LS1、 LS2、LS3之各平面圖。 . 如第5圖所示，供給-Vy的電壓至靜電電極P11及pi3， 5且供給+Vx的電壓至P12及P14。 第2段LS2的各電極則施加與LS1的各電極及電位相反 之電壓。亦即，施加+Vy，於P21及p23，且施加％，於PM及 鲁 P24。 又，施加與LSI相同之電壓於第3段LS3的各電極。 1〇 如此一來，可對12個靜電電極使用4種電壓值。將業經 ，聚焦控制部2G9整形之電子束截面積乘上再聚焦係數後 算出前述電壓，並供給至各電極。 .帛6®個示用⑽財電—於再聚焦鏡之各電 極之再聚焦電路的構造圖。 15 再聚焦電路42將由再聚焦控制部209指定之用以實施 • 再聚焦的4種電壓值(數位值〕分別透過D A C 4 3轉換成類比資 料後，再經由電壓增幅器44將業經轉換之類比電壓供給至 ^ 上述預定電極。 、經整形之電子域_可從儲存於記,_41的曝光光 罩資料及電子束偏折量資料中算出。例如，如第7圖所示， 選擇曝光光罩開口 llGa ’且將經偏折之電子束邱照射至曝 光光罩11⑽—為咖。㈣，經整形之電子束截面 積Fes即為開口 ma與電子束載面刪的重疊部分之面積。 藉由以下眾騎知的料可算料聚焦係數。 25利用2種尺寸的電子束，分別求出得以使電子束邊緣的 200823969 模糊量為最小之再聚焦量。 通過矩形開口 103a的電子束電流為固定電流，且再聚 焦量幾乎與通過曝光光罩11〇的電子束電流成正比，故與曝 光光罩110及在該位置處之電子束影像彼此重疊之面積成 5正比的電麼’亦即因應偏折器104、106之偏折量的電壓供 給至再聚焦鏡的各電極，作為再聚焦量。 為決定再聚焦量’可依下列方法測定電子束邊緣模糊 ϊ。亦即，如第8(a)圖所示，於矽Si之晶圓81上形成電子反 射率較矽si為高的鈕膜82。再用偏折器1〇4、1〇6使電子束 10進打掃描，以使電子束83橫穿過鈕膜82。此時，可經由電 子檢測斋檢測出來自照射點的反射電子84。然後如第8作） 圖所不，求出電子檢測量。將該電子檢測量對電子束掃描 位置進行微分，以取得如第8(c)圖所示之波形後，求出其最 大值從90〇/〇變化至1〇%的距離，作為電子束邊緣模糊量§。 15 調整施加於各電極的電壓並求出G^，錢該電子束 邊緣模糊量為最小。 上述處理係針對兩種不同截面積之電子束進行。 接著’如第9圖所示，使電子束截面積與再聚焦量（再 聚焦係數Gl〜G4)之間的關係近似直線。若截面積為Sl時之 20再來焦里為GSl，且戴面積為之再聚焦量為GS2，即可 利用通過前述2點的直線求出截面積及再聚焦量之間的相 =關係。對4種再聚焦係數同樣可求出相關關係。據此，任 4狀之方塊圖案均可從其面積決定再聚焦係數。 (¾子束曝光方法） 接下來"兒明使用上述電子束曝光裝置之曝光方法。 200823969 進行電子束曝光時，每選擇一次曝光光罩就得調整電 子束之焦點，故需決定再聚焦係數。 正如同用第8圖及第9圖進行之說明，再聚焦係數係對2 種不同截面積之電子束測定電子束模糊量，並決定使電子 5束模糊量為最小之再聚焦係數〇1至〇4。 所照射之電子束截面積可從記憶有曝光資料的記憶部 41挑選出尺寸，乘上對應其尺寸之再聚焦係數^至^後， 決定施加於各電極的電壓值。 該電壓值之計算係與施加電壓於偏折器1〇4、1〇6同時 10進行。過去，儘管施加於偏折器的電壓到安定為止僅需耗 費50[ns]的時間，但再聚焦電流卻需要3〇〇[ns]左右的安定時 間，故等待曝光時間很長。在本實施型態中，由於施加電 壓於靜電電極，故用以修正焦點之電壓的安定時間縮短為 50[ns]即使把根據電子束尺寸決定施加於各電極之電壓值 15的時間也考慮在内，等待曝光時間亦僅需100[ns]左右，比 以往快3倍’可在短時間内開始曝光且可提升曝光效率。 如上述說明，在本實施型態中，為進行用以調整電子 束焦點之再聚焦，裝設有以靜電電極構成的再聚焦鏡。該 再聚焦鏡係由3段4極透鏡重疊而構成，俾使通過其間的電 20子束進行聚焦者。此時，施加於構成再聚焦鏡之各電極的 電壓係因應電子束截面積以進行調整者。藉此，即使電子 束的電子量有所變化，亦可因應電子束截面積之大小進行 對焦。而且，由於僅使用靜電電極施加電壓來調整電場， 故可加快再聚焦速度，且可提升曝光效率。 25 此外，雖在本實施型態中說明了為進行再聚焦而對再 200823969 聚焦鏡之各電極施加4種電壓值，但不限於此，亦可對構成 3段4極透鏡的12個靜電電極分別施加電壓。此時，可進行 精度更佳的再聚焦。 又，雖在本實施型態中說明了再聚焦鏡係由3段4極透 5 鏡重疊而構成，但不限於此，亦可用較3段更多之段數構成。 【圖式簡單說明】 第1圖係本發明之電子束曝光裝置的構造圖。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam exposure apparatus and an electron beam exposure method. In particular, a variable rectangular opening and a Character Projection pattern can be used to change the shape and size of an electron beam. An electron beam exposure device and an electron beam exposure method. [Previous Background of the Invention In recent years, in an electron beam exposure apparatus, in order to improve production efficiency, a variable rectangular opening or a plurality of reticle patterns are prepared on a reticle, and a variable rectangular opening is selected by electron beam deflection or Most of the reticle pattern is transferred to the sample for transfer exposure. 15 Such exposure devices are electron beam exposure devices for deformable beam exposure. The deformable beam exposure is performed by deflecting an electron beam, irradiating an electron beam to one of the pattern areas selected from a plurality of patterns disposed on the reticle, forming a cross-section of the electron beam into a pattern shape, and then using a deflector of the rear stage The electron beam passing through the mask is deflected back and reduced in accordance with a certain reduction ratio determined by the electron optical system, and then transferred onto the sample. 20 In the deformable beam exposure, if a pattern with a high usage rate is prepared in advance on the mask, the number of necessary exposure shots can be greatly reduced and the production efficiency can be improved as compared with a case having only a variable rectangular opening. On the other hand, if the variable beam opening and the deformable beam pattern are used for electron beam exposure, the size of the electron beam will vary with each shot, causing the electron beam to be out of focus and blurring the electron beam. For example, when the small beam 25 200823969 - 彳 electron beam is used to focus on the surface of the sample, such as the large-sized electron beam..., #光, the total current of the electron beam will increase, causing the focal length to prolong, so that the electron beam appears on the surface. Blurring.纟 To prevent such occurrences of electron beam loss, it has been proposed to calculate the area of the refocusing coil and correct the current of each of the 516 variable rectangular openings. A method of controlling a focus coil in accordance with the size of a rectangular electron beam is disclosed in the patent document. Further, Patent Document 2 discloses a method of measuring the offset of the electron beam axis and correcting it while performing refocusing of the electron beam. 10 As described above, when a variable rectangular opening and a deformable beam pattern are used, electron beam loss and focus can be prevented by moving the focus of the electron beam at each shooting. - Specifically, a refocusing coil is provided, and a current amount proportional to the cross-sectional area of the shaped electron beam flows into the refocusing coil, and the focus of the electron beam is adjusted by 15 points. For example, when the size of the electron beam is large, a larger current of φ proportional to the cross-sectional area of the electron beam flows into the refocusing coil to enhance the focusing effect of the electron beam. However, it takes time to perform refocusing, and despite the implementation of deformable beam exposure, there is still a problem that the exposure efficiency cannot be improved. For example, although the shaped electron beam only needs to spend about 20 ns for about 20 ns, when refocusing is performed, until the predetermined current flows into the refocusing coil and the current becomes stable, it takes about 300 ns, causing waiting for exposure. Time has become lengthy. [Patent Document 1] JP-A-56-94740 (Patent Document 2) Japanese Laid-Open Patent Publication No. SHO-58-121625 In the electron beam exposure which can change the shape and size of the electron beam, the electron beam exposure apparatus and the electron beam exposure method which shorten the refocusing time of 5 joules and improve the production efficiency can be shortened. The above problems can be solved by an electron beam exposure apparatus characterized by comprising an electron gun, a shaping mechanism, a projection lens, a refocusing mirror and a control mechanism. The electron gun is used to emit an electron beam, and the shaping mechanism has an opening for shaping the electron beam, and the projection lens is used to image the electron beam on the sample surface, and the refocusing mirror system Provided above the projection lens, formed by a multi-pole electrostatic lens for correcting the defect of the electron beam, and the control mechanism can apply the electron beam of the electron beam shaped by the shaping mechanism to the refocusing lens. The area of the voltage. Φ In the electron beam exposure apparatus of this type, the refocusing mirror may have three 4-pole electrostatic electrodes in the electron beam axis direction of the electron beam, and the first and the third-stage 4-electrode electrostatic electrodes The length of the three-stage electrode can be the same, and the length of the second-stage electrode can be twice the length of the first-stage electrode. Further, the voltage applied to the x-direction electrode of the second, second, and third stages and the voltage applied to the y-direction electrode may be opposite in polarity, and the voltage applied to the sense electrode of the second stage may be The voltage applied to the X-direction electrode of the second stage may be opposite in polarity, and the voltage applied to the X-direction electrode of the first stage and the voltage of the X-direction electrode applied to the third stage may be the same polarity The voltage applied to the y-direction electrode of the first step of the first 25th paragraph and the voltage of the y-direction electric power applied to the third stage of 200823969 may be the same polarity. In the present invention, in order to perform refocusing for adjusting the focus of the electron beam, a refocusing mirror provided with an electron beam composed of an electrostatic electrode is mounted. The refocusing mirror system ^ is composed of a stack of three 4-pole lenses, and the electron beam is passed through the electron beam between them. The voltage applied to each of the electrodes constituting the refocusing mirror is adjusted in accordance with the cross-sectional area of the shaped electron beam. Thereby, even if the amount of electrons of the irradiated electron beam changes, focusing can be performed on the surface of the sample. Moreover, since the electrostatic electrode is used and the electric field is adjusted by the voltage, the refocusing speed can be accelerated and the exposure efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a configuration diagram of an electron beam exposure apparatus of the present invention. Fig. 2 (8) and (b) are views showing the construction of a refocusing mirror of the electron beam exposure center of the present invention. Fig. 3 is an explanatory diagram of electronic deflection control of a gray 4-electrode electrostatic electrode. 15 Fig. 4 is an explanatory diagram of an electronic orbit of a 3-stage 4-pole electrostatic electrode. • Fig. 5 is a representation of the connection relationship of the electrodes of the refocusing mirror. Fig. 6 is an explanatory diagram of a refocusing circuit. Figure 7 is an explanatory diagram of the amount of refocusing. Fig. 8 (a) to (c) are explanatory diagrams for calculating the refocusing coefficient (1). 2〇 胄9® calculates the refocusing factor (2). t. The actual package mode of the invention. The embodiment of the invention will be described below with reference to the drawings. First " construction of the electron beam exposure device. Next, a refocusing mirror for refocusing the electron beam will be described. Finally, the method of electron beam exposure 200823969 is explained. (Structure of Electron Beam Exposure Apparatus) f1 is a configuration diagram of the electron beam exposure apparatus of the fourth embodiment. The monthly private beam exposure device can be roughly divided into electronic optical columns 1 and 5 to control the control fan of each part of the electron optical column (10). The electron optical column (8) is composed of an electron beam generating portion 13G, a mask deflecting portion (10), and a substrate deflecting portion 15?, and the inside thereof is depressurized. In the electron beam generating unit U0, the electron beam generated from the electron (4) i is subjected to focusing at the 1st magnetic lens 102, and then penetrates the rectangular opening position on the cover 10 of the electron beam shaping light 10 to make the electron beam The cross section of the four is formed into a rectangular shape. Thereafter, the electron beam EB is imaged on the exposure mask by the second electromagnetic lens 1〇5 on the mask deflecting portion 14A. Then, the second and second static deflectors 104 and 106 of the electron beam are deflected to form a specific pattern S on the exposure mask 11 to form a cross-sectional shape of the pattern 8. In addition, although the exposure mask 110 is fixed on the mask platform 123, the mask platform 123 can be horizontally moved, if the deflection range (electron beam) exceeding the first and second electrostatic deflections 1 § 104, 106 is used. In the partial pattern s, the pattern s can be moved to the electron beam deflection field by moving the mask platform 123. In place of the exposure mask 110, an opening portion for changing the electron beam into a predetermined shape may be disposed. The third and fourth electromagnetic lenses 1〇8 and lu disposed above and below the exposure mask can image the electron beam EB on the substrate W by adjusting the amount of current. The electron beam EB of the exposure mask 110 is deflected back to the optical axis (electron beam axis) C by the deflection of the third and fourth electrostatic deflectors 25 112 and 113, and then reduced by the second electromagnetic lens ii4 of 200823969. Its size. The mask deflecting portion 140 is provided with first and second correcting coils 1〇7 and 1〇9, and the first and second correcting coils are described, and the correction can be made to the fourth to fourth electrostatic deflectors 104 and 106. , 112, 113 electron beam deflection phenomenon. 5, the electron beam EB passes through the opening 115a on the shielding plate 115 of the substrate deflecting portion 150, and the focus is adjusted by the refocusing mirror 128 in response to the cross-sectional area of the electron beam Εβ, and then the first and second are borrowed. The projection electromagnetic lenses 116, 121 are projected onto the substrate W. Thereby, the pattern image of the exposure mask 11 is transferred onto the substrate w at a predetermined reduction ratio of, for example, a 1/10 reduction ratio. The first substrate deflecting portion 150 is provided with a fifth electrostatic deflector 119 and an electromagnetic deflector 120'. The deflector 119, 12 〇 deflects the electron beam EB to project a pattern image of the exposure mask 110 onto the substrate. The intended location of w. Further, the substrate deflecting portion 150 is provided with third and fourth correction coils 117 and 118 for correcting the phenomenon of deflection of the electron beam EB on the substrate w. The substrate W is fixed to the wafer level σ 124 horizontally movable by the driving unit 125 such as a motor, and the entire surface of the substrate w is exposed via the moving wafer stage 124. On the other hand, the control unit 200 includes an electronic grab control unit 202, an electro-optical system control unit 203, a mask deflection control unit 2〇4, a mask platform control unit 20205, a mask control unit 206, and a substrate deflection control unit 207. The wafer platform control unit 208 and the refocus control unit 209. The electronic grab control unit 202 controls the electron gun 101 to control the acceleration voltage and electron beam radiation conditions of the electron beam. Further, the electro-optical system control unit 203 controls the amount of current flowing into the electromagnetic lenses 1 2, 105, 108, 1 Η, 114, 116, and 121 to adjust the magnification and focus position of the electro-optical system constituted by the electromagnetic lens 25. The shielding control unit 206 deflects the electron beam EB generated before the start of exposure to the shielding plate 115 by controlling the voltage applied to the shielding electrode 127 by 10200823969 to prevent the electron beam from being irradiated onto the substrate W before exposure. The substrate deflection control unit 207 deflects the electron beam £3 to a predetermined position of the substrate w by controlling the voltage applied to the fifth electrostatic deflector 5 n9 and the amount of current flowing into the electromagnetic deflector 120. The wafer stage control unit 2〇8 adjusts the driving amount of the driving unit 125 to horizontally move the substrate to irradiate the electron beam EB to the intended position of the substrate W. Further, the focus control unit 209 supplies the necessary current to each of the electrodes constituting the refocusing mirror by penetrating the exposure mask 11 and the shaped electric beam 10 ΕΒ < sectional area, and the respective portions 202 to 209 can be operated by the workstation The integrated control system 2〇1 is integrated and controlled. (Refocusing mirror) 15 Fig. 2 shows the construction of a refocusing mirror used in this embodiment. Fig. 2(a) is a plan view showing the refocusing mirror 128 provided above the electron gun 1〇1 side of the projection lenses 116 and 121, and Fig. 2(b) is a cross-sectional view showing the refocusing mirror 128 viewed from the front. As shown in Fig. 2, the refocusing mirror 128 is constructed by superimposing a 4 20-electrode lens using four electrostatic electrodes at a predetermined interval in the electron beam axis direction (the x-axis direction). The 4-pole electrostatic lens is divided into the first segment, the second segment, and the third segment along the electron beam irradiation direction, and is separated from the electron grabber, and the 4-pole electrostatic lens of the first segment, the second segment, and the third segment are respectively Marked as LSI, LS2, LS3. The 25-electrode electrostatic lens LSI is composed of four electrostatic electrodes Pli, P12, P13, and P14 11 200823969, and is disposed at equal intervals in the x-axis direction and the z-axis direction, centering on the electron beam axis (z-axis). For example, each electrode has a length of ... claw (five). The four-electrode electrostatic lens LS2 is composed of four electrostatic electrodes p2i, P22, P23, and P24, and is disposed in the lower stage of the LSI. The 4-pole electrostatic lens [in the 5 Z-axis direction and the four electrodes of the LSI are arranged at a predetermined interval (^ overlapping, and the predetermined interval G1 is exemplified by 5 。. The electrode length of the 4-pole electrostatic lens LS2 [ 2 is twice the length L1 of each electrode of the four-electrode lens LSI. For example, when L1 is l〇mm, L2 is 20 mm. The 4-pole electrostatic lens LS3 is composed of four electrostatic electrodes p3i, P32, P33, and P34. And disposed in the lower part of LS2. The four electrodes of the 4-pole electrostatic lens LS3 are arranged to overlap with the four electrodes of LS2 at a predetermined interval 〇2 in the Z-axis direction, and the predetermined interval G2 is exemplified by 5 mm. The 4-pole electrostatic lens LS3 The length of each electrode B is the same as that of the LSI. Next, the focus of the electronic focus 15 can be adjusted by the refocusing mirror thus constructed. First, the amount of electron deflection after passing through the first-stage four-electrode electrostatic lens will be described. The figure shows a plan view of a 1-segment 4-pole electrostatic lens. The potential distribution 0 of the lens is expressed as ¢ = A(x2 - y2) / r. 2. Here, Γ 2 2 mm. The electrons passing through the Z-axis can be It is advanced by 20 forces in the X-axis direction and the γ-axis direction. When x = lmm, the electric field is £(x 2 1) = -d 0 /dx = 40/9[V/m m] Here, the amount of polarization when passing electrons at a distance of 1 mm from the electron axis at a position of 5000 mm from the z-axis direction is discussed. It is assumed that the amount of electron polarization when the corresponding electron passes between the parallel plates is considered. If the electric field at both ends is chaotic, the amount of deflection D at the length 1 of the distance electrode can be expressed by the following formula: 12 25 200823969 D=(lb/2d)x(Vd/V0) (i) Here b is the length of the parallel plate, Vd is the voltage applied between the plates, and V0 is the incident voltage of the electron (take 50kv as an example). In this formula, 2Vd/d is the electric field E. In formula (1), if b = L〇[mm], E = 4〇/9[v/叫, v〇= 50000[v], 1=5000[mm], then the deflection distance D is 1 n pad p, ie, deflection l[ Mm] can make the focus on the electron beam axis, so the purpose can be achieved by adjusting the voltage applied to the electrode. Thus, the focus of the electron can be adjusted by a 4-pole lens. Therefore, even 4 poles When the lens is composed of multiple segments, the focus of the electron can also be adjusted. The image of the electronic circuit of the 3# and 4 pole electrostatic electrodes is shown in Fig. 4. The z-axis of Fig. 4 is the electron beam. In the figure, the traveling direction of the electron beam advances from left to right. 15 The X-axis side of Fig. 4 indicates the electron beam orbit in the X direction, and the Cry axis side indicates the electron beam in the direction y • C2. As shown in Fig. 4 When observing the obstruction G in the x direction, it is found that the first quadrupole lens functions as a convex lens, the second quadrupole lens functions as a concave lens, and the third quadrupole lens functions as a convex lens. Further, when attention is paid to observing the trajectory C2 in the y direction, it is found that the second-stage quadrupole lens 20 functions as a concave lens, the second-stage quadrupole lens functions as a convex lens, and the third-stage quadrupole lens functions as a concave lens. Moreover, the χ direction and the angle of incidence are almost the same at the incident angle to the final focus Z2. Therefore, the focus can be easily adjusted by using the aforementioned three-stage 4-pole electrostatic electrode. The refocusing control unit 209 applies a predetermined voltage to each of the electrodes of the refocusing mirror constructed as shown in Fig. 2 so that the entire refocusing mirror 128 generates a necessary electric field sufficient for refocusing at 200823969. In the present embodiment, a voltage of a polarity as shown in Fig. 5 is applied. Fig. 5 is a plan view showing the four-electrode electrostatic lenses LS1, LS2, and LS3 in a simple manner. As shown in Fig. 5, the voltage of -Vy is supplied to the electrostatic electrodes P11 and pi3, 5, and the voltage of +Vx is supplied to P12 and P14. The electrodes of the second stage LS2 are applied with voltages opposite to the respective electrodes and potentials of LS1. That is, +Vy is applied to P21 and p23, and % is applied to PM and Lu P24. Further, the same voltage as the LSI is applied to each electrode of the third stage LS3. 1〇 As a result, four voltage values can be used for 12 electrostatic electrodes. The electron beam cross-sectional area shaped by the focus control unit 2G9 is multiplied by the refocusing coefficient, and the voltage is calculated and supplied to each electrode.帛6® Display (10) Financials—Structure of the refocusing circuit of each electrode of the refocusing mirror. The refocusing circuit 42 converts the four kinds of voltage values (digital values) designated by the refocusing control unit 209 for refocusing into analog data, and then converts the analogy by the voltage booster 44. The voltage is supplied to the predetermined electrode. The shaped electronic domain _ can be calculated from the exposure mask data stored in the record, _41, and the electron beam deflection amount data. For example, as shown in Fig. 7, the exposure mask is selected. The opening llGa' and the deflected electron beam are irradiated to the exposure mask 11 (10) - (4), the shaped electron beam cross-sectional area Fes is the area of the overlapping portion of the opening ma and the electron beam carrying surface. The following materials can be used to calculate the focus coefficient. 25 Using two types of electron beams, the refocusing amount that minimizes the amount of blurring of the beam edge of 200823969 is obtained. The beam current passing through the rectangular opening 103a is a fixed current. And the amount of refocusing is almost proportional to the beam current passing through the exposure mask 11, so that the area of the exposure mask 110 and the electron beam image at the position overlap each other is 5 proportional That is, the voltage corresponding to the deflection amount of the deflectors 104, 106 is supplied to each electrode of the refocusing mirror as the refocusing amount. To determine the refocusing amount, the electron beam edge blur can be measured in the following manner. As shown in Fig. 8(a), a button film 82 having a higher electron reflectance than 矽si is formed on the wafer 81 of 矽Si. The electron beam 10 is further driven by the deflectors 1〇4, 1〇6. Scanning is performed so that the electron beam 83 traverses the button film 82. At this time, the reflected electrons 84 from the irradiation spot can be detected via the electronic detection. Then, as shown in Fig. 8, the amount of electron detection is determined. The electron detection amount is differentiated from the electron beam scanning position to obtain a waveform as shown in FIG. 8(c), and the maximum value is changed from 90 〇/〇 to 1〇% as the edge of the electron beam. Fuzzy amount §. 15 Adjust the voltage applied to each electrode and find G^, which is the minimum amount of edge blur of the electron beam. The above treatment is performed for two electron beams of different cross-sectional areas. Next, as shown in Fig. 9, the relationship between the cross-sectional area of the electron beam and the refocusing amount (refocusing coefficients G1 to G4) is approximately straight. If the cross-sectional area is S1 and the refocusing is GS1, and the wearing area is GS2, the phase relationship between the cross-sectional area and the refocusing amount can be obtained by using the straight line of the above two points. Correlation can also be obtained for the four refocusing coefficients. Accordingly, any square pattern of squares can determine the refocusing coefficient from its area. (3⁄4 beamlet exposure method) Next, the exposure method of the above electron beam exposure device is used. 200823969 When performing electron beam exposure, the focus of the electron beam must be adjusted every time the exposure mask is selected, so the refocusing factor needs to be determined. As explained in Fig. 8 and Fig. 9, the refocusing coefficient measures the electron beam blur amount for two electron beams of different cross-sectional areas, and determines the refocusing coefficient 使1 which minimizes the blur amount of the electron 5 beam. As for 4. The cross-sectional area of the electron beam to be irradiated can be selected from the memory portion 41 in which the exposure data is stored, and multiplied by the refocusing coefficient ^ to ^ corresponding to the size thereof to determine the voltage value applied to each electrode. The calculation of the voltage value is performed simultaneously with the application of voltage to the deflectors 1〇4, 1〇6. In the past, although it took only 50 [ns] for the voltage applied to the deflector to settle, the refocusing current required a timing of about 3 〇〇 [ns], so the waiting time was long. In the present embodiment, since the voltage is applied to the electrostatic electrode, the settling time for correcting the voltage of the focus is shortened to 50 [ns], and the time for applying the voltage value 15 applied to each electrode according to the size of the electron beam is considered. Inside, waiting for the exposure time is only about 100 [ns], which is 3 times faster than before. 'The exposure can be started in a short time and the exposure efficiency can be improved. As described above, in the present embodiment, in order to perform refocusing for adjusting the focus of the electron beam, a refocusing mirror composed of an electrostatic electrode is mounted. The refocusing mirror is constructed by superposing three 3-pole lenses, and the focus is made by the electric beamlets passing therebetween. At this time, the voltage applied to each of the electrodes constituting the refocusing mirror is adjusted in accordance with the cross-sectional area of the electron beam. Thereby, even if the electron amount of the electron beam changes, the focus can be focused on the cross-sectional area of the electron beam. Moreover, since the electric field is adjusted by applying a voltage only using the electrostatic electrode, the refocusing speed can be accelerated, and the exposure efficiency can be improved. Further, although in the present embodiment, four kinds of voltage values are applied to the respective electrodes of the re-focusing mirror of the 200823969 for refocusing, the present invention is not limited thereto, and twelve electrostatic electrodes constituting the three-segment quadrupole lens may be used. Apply voltage separately. At this point, better refocusing is possible. Further, in the present embodiment, it has been described that the refocusing mirror is constituted by three-segment four-pole mirrors, but the present invention is not limited thereto, and may be constituted by a larger number of segments than three segments. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a configuration diagram of an electron beam exposure apparatus of the present invention.
第2(a)、（b)圖係本發明之電子束曝光裝置之再聚焦鏡 的構造圖。 10 帛3圖係、1段4極靜電電極之電子偏折控制的說明圖。 第4圖係3段4極靜電電極之電子軌道的說明圖。 第5圖係再聚；鏡之各電極之連接關係的表示圖。 第6圖係再聚焦電路的說明圖。 第7圖係再聚焦量的說明圖。 15 f 8圖⑷〜⑷係計算再聚焦係數的說明圖（其D。 第9圖係計算再聚焦係數的說明圖（其2)。 【主要元件符號說明】 100···電子光學柱 200...控制部 130··.電子束生成部 140···光罩偏折部 150…勒反偏折部 101·.·電子搶 EB…電子束 102···第1電磁透鏡 103…電子束整形用光罩 103a.··矩形開口 105…第2電;^透鏡 110…曝光光罩 104···第1靜電偏折器 106···第2靜電偏折器 S…圖案 123…光罩平合 200823969Figs. 2(a) and 2(b) are views showing the construction of a refocusing mirror of the electron beam exposure apparatus of the present invention. An explanatory diagram of the electronic deflection control of the 10 帛3 system and the 1-stage 4-pole electrostatic electrode. Fig. 4 is an explanatory view of an electron orbit of a 3-stage 4-pole electrostatic electrode. Figure 5 is a representation of the re-aggregation; the connection relationship of the electrodes of the mirror. Fig. 6 is an explanatory diagram of a refocusing circuit. Fig. 7 is an explanatory diagram of the amount of refocusing. 15 f 8 (4) to (4) are explanatory diagrams for calculating the refocusing coefficient (D. Fig. 9 is an explanatory diagram for calculating the refocusing coefficient (2). [Explanation of main component symbols] 100···Electronic optical column 200. .. control unit 130··. electron beam generating unit 140··removal deflecting unit 150...reverse deflecting unit 101···electron grabbing EB...electron beam 102···first electromagnetic lens 103...electron beam Shaped mask 103a.·Rectangle opening 105...second power;^ lens 110...exposure mask 104···first electrostatic deflector 106···second electrostatic deflector S...pattern 123...mask平合200823969
108…第3電磁透鏡 111…弟4電石兹透鎖^ 112.. .第3靜電偏折器 113…第4靜電偏折器 C...光軸(電子束軸） 114.••第5電磁透鏡 107.. .第1修正線圈 109…第2修正線圈 115…遮蔽板 115a···開口 128.. .再聚焦鏡 116…第1投影用電磁透鏡 121…第2投影用電磁透鏡 W…鉍 119.. .第5靜電偏折器 120.. .電磁偏折器 117…第3修正線圈 118.. .第4修正線圈 125.. .驅動部 124…晶圓平台 202…電子槍控制部 203.. .電子光學系統控制部 204…光罩偏折控制部 205.. .光罩平台控制部 206.. .遮蔽控制部 207…基板偏折控制部 208.. .晶圓平台控制部 209.. .再聚焦控制部 127.. .遮蔽電極 201.. .統合控制系統 LSI…第1段4極靜電透鏡 LS2…第2段4極靜電透鏡 LS3…第3段4極靜電透鏡 P11...靜電電極 P12...靜電電極 P13...靜電電極 P14...靜電電極 L1…電極長度 P21...靜電電極 P22...靜電電極 P23...靜電電極 P24...靜電電極 L2...電極長度 G1...間隔 P31...靜電電極 P32...靜電電極 18 200823969 P33...靜電電極 81…晶圓 P34…靜電電極 82…钽膜 L3…電極長度 83...電子束 G2...間隔 84…反射電子 Cl..電子束軌道 (5…電子束邊緣模糊量 C2…電子束軌道 Gi...再聚焦係數 Z2...隶終焦點 G2...再聚焦係數 42...再聚焦電路 〇3...再聚焦係數 43...DAC G4...再聚焦係數 44...電壓增幅器 S!...截面積 41...記憶部 S2...截面積 110a···開口 G&...再聚焦量 EBS...截面 Fes...截面積 GS2...再聚焦量 19108...3rd electromagnetic lens 111...Dia 4 electric stone plate through lock ^ 112.. 3rd electrostatic deflector 113... 4th electrostatic deflector C... optical axis (electron beam axis) 114.•• 5th Electromagnetic lens 107.. first correction coil 109...second correction coil 115...shield plate 115a···opening 128.. refocusing mirror 116...first projection electromagnetic lens 121...second projection electromagnetic lens W...铋 119.. . 5th electrostatic deflector 120.. electromagnetic deflector 117... third correction coil 118.. 4th correction coil 125.. drive unit 124... wafer platform 202... electron gun control unit 203 . . . Electron optical system control unit 204... reticle deflection control unit 205.. reticle stage control unit 206.. occlusion control unit 207... substrate deflection control unit 208.. wafer platform control unit 209. . Refocusing control unit 127.. shielding electrode 201.. integration control system LSI... first stage 4-pole electrostatic lens LS2... second-stage 4-pole electrostatic lens LS3... third-stage 4-pole electrostatic lens P11... Electrostatic electrode P12...electrostatic electrode P13...electrostatic electrode P14...electrostatic electrode L1...electrode length P21...electrostatic electrode P22...electrostatic electrode P23...electrostatic electrode P24...electrostatic electrode L2. ..Electricity Length G1...interval P31...electrostatic electrode P32...electrostatic electrode 18 200823969 P33...electrostatic electrode 81...wafer P34...electrostatic electrode 82...film L3...electrode length 83...electron beam G2. .. interval 84...reflecting electrons Cl.. electron beam orbital (5...electron beam edge blurring amount C2...electron beam orbital Gi...refocusing coefficient Z2...final focus G2...refocusing factor 42.. Refocusing circuit 〇3...refocusing coefficient 43...DAC G4...refocusing coefficient 44...voltage booster S!...cross-sectional area 41...memory part S2...cross-sectional area 110a···Open G&...Refocus amount EBS...section Fes...cross-sectional area GS2...refocus amount 19