200914989 九、發明說明： 【發明所屬之技術領域】 本發明係關於用於製造攝影元件、液晶顯示裝置 (Liquid Crystal Display:以下稱爲LCD)、半導體裝置等的 灰階遮罩、及使用此遮罩的圖案轉印方法，特別是關於適 合用於製造薄膜電晶體液晶顯示裝置的薄膜電晶體基板 (TFT基板）所使用的灰階遮罩以及圖案轉印方法。 【先前技術】 現在’在LC D的領域中，薄膜電晶體液晶顯示裝置 (Thin Film Transistor Liquid Crystal Display :以下稱爲 TFT-LCD)係相較於CRT(陰極線管），因爲有能輕易薄型化 且消耗電力低的優點，所以現在正迅速地商品化。TFT-LCD 具有以矩陣狀排列的各畫素上排列有TFT之構造的TFT 基板，及對應各畫素而排列有紅色、綠色以及藍色之畫素 圖案的彩色濾色片係在液晶層的介入下而重合的槪略構造 。在TFT-LCD中，製造步驟數很多，光是製造TFT基板就 要使用 5〜6片光罩。在這種狀況下，在「月刊 FPD Intelligence」、1 999年5月、P.31〜35(非專利文獻1)中， 提出了使用4片光罩來進行TFT基板之製造的方法。 此方法係藉由使用具有遮光部、透光部和半透光部（ 灰階部）的光罩（以下稱爲灰階遮罩），來減低使用的遮罩片 數。在此，半透光部就是指在使用遮罩並將圖案轉印至被 轉印體上時，使透過之曝光光線的透過量減低既定量，且 控制被轉印體上之光阻膜的顯影後之殘膜量的部分，同時 200914989 具備這種半透光部、遮光部、透光部的光罩則被稱爲灰階 遮罩。 於第8圖及第9圖（第9圖係第8圖之製造步驟的後續 )表示使用灰階遮罩之TFT基板的製造步驟之一例。 在玻璃基板1上形成閘極用金屬膜，藉由使用光罩的 光微影製程來形成閘極2。爾後，形成閘絕緣膜3、第1半 導體膜4(a-Si)、第2半導體膜5(N + a- Si)、源極汲極用金屬 膜6以及正型光阻膜7(第8(1)圖）。接著，使用具有遮光部 11、透光部12和半透光部13的灰階遮罩10，使正型光阻 膜7曝光並顯影，藉以形成第1光阻圖案7 a，使其覆蓋TFT 通道部以及源極汲極形成區域、資料傳輸線形成區域，且 通道部形成區域變得比源極汲極形成區域還要薄（第8(2) 圖）。接著，以第1光阻圖案7a作爲遮罩，蝕刻源極汲極 用金屬膜6以及第2、第1半導體膜5、4(第8(3)圖）。接著 ，利用氧氣來進行灰化，以除去通道部形成區域薄的光阻 膜，並形成第2光阻圖案7b(第9(1)圖）。爾後，以第2光 阻圖案7b作爲遮罩，蝕刻源極汲極用金屬膜6，形成源極/ 汲極6a、6b，接著蝕刻第2半導體膜5(第9(2)圖），最後剝 離殘存的第2光阻圖案7b(第9(3)圖）。 作爲能在此使用的灰階遮罩，已知有半透光部以微細 圖案所形成之構造者。例如，如第1 0圖所示，具有與源極 /汲極對應之遮光部1 1 a、1 1 b、透光部1 2及與通道部對應 之半透光部（灰階部）1 3，半透光部1 3係形成由使用灰階遮 罩之LCD用曝光機的解析極限以下之微細圖案所組成的遮 200914989 光圖案13a的區域。遮光部lla、lib和遮光圖案13a 是由一起以鉻和鉻化合物等的相同材料組成之相同厚 膜所形成。使用灰階遮罩之LCD用曝光機的解析極限 部分的情況下，步進式之曝光機則是大約3 μ m，鏡面 式之曝光機則是大約4 # m。因此，例如，第1 〇圖中 將半透光部1 3之透過部1 3b的間隔寬度設爲未滿3 μ 將遮光圖案13a之線寬設爲曝光機之解析極限以下的 3 /i m。 上述微細圖案型的半透光部在設計時能考慮到， 階部分的設計，具體而言，會有把用於使具有遮光部 光部之中間半色調效果的微細圖案做成線與間隙（1 i n e space)型或做成點狀（網點）型，或者做成其他圖案的選 此外，在線與間隙型的情況下，線寬要做到什麼程度 怎麼處理光透過部分和遮光部分的比率，要將全體的 率設計到什麼程度等。 另一方面，在特開2002- 1 89280號公報（專利文獻 ’以往提出了將欲進行半色調曝光的部份作爲半透光 半色調膜（半透光膜）。能藉由使用此半色調膜來減少 調部分的曝光量，以進行半色調曝光。在使用半色調 情況’設計中，會檢討全體的透過率必須要是多少， 罩中無論是否爲半色調膜的膜種類（材料），藉由選擇 就能生產遮罩。在製造遮罩時進行半色調膜的膜厚控 因爲當以灰階遮罩的灰階部來形成TFT通道部的情況 若是半色調膜，就可輕易地藉由光微影步驟來進行圖 通常 度的 在大 投影 ，能 m ’ 未滿 在灰 和透 and 擇， ，要 透過 1)中 性的 半色 膜的 在遮 膜厚 制。 下， 案化 200914989 ，所以會有即使TFT通道部之形狀是複雜的圖案形狀也可 行的優點。 【發明内容】 將上述半透光部作爲半色.調膜（半透光膜）的上述灰階 遮罩係相較於前述的微細圖案型的灰階遮罩，在形成一定 . 以上面積的半透光部時會非常有用。在微細圖案型之半透 光部的情況下，會有該面積變大則圖案資料變膨脹的問題 ^ ，但在採用半色調膜的半透光部中就不會發生那種問題。 第11 (a)圖係表示以這種半透光部作爲半色調膜（半透 光膜）的灰階遮罩之一例。亦即，灰階遮罩20係具備形成 爲既定圖案狀的遮光部21、透光部22和半透光部23，如 第1 1(b)圖（沿著第丨1(a)圖的L-L線之截面圖）所示，遮光部 21係構成爲在透明基板24上具有遮光膜25，透光部22係 構成在透明基板24露出的部分上，另外，半透光部23係 構成爲在透明基板24上具有半透光膜26。 { i 不過’近幾年，特別是隨著TFT通道部之圖案的微細 化’在灰階遮罩中也需要越來越細微的圖案，本發明者們 發現即使在將半透光膜用在上述半透光部的灰階遮罩中也 會發生新的課題。亦即，例如，如上述第Η圖所示，藉由 半透光膜26來形成遮光膜25之2個遮光部21、21所包夾 之寬度Α爲7 // m左右之半透光部2 3的灰階遮罩之情況下 ’在使用此遮罩時的曝光機之該半透光部的透過光之光強 度分佈係如第1 2圖所示。此外，作爲曝光機的曝光光源， 則使用包含例如g線（波長4 3 6 n m)及i線（波長3 6 5 n m)的 200914989 3 5 0 n m〜4 5 0 n m之波長區域的光源。按照此光強度分佈，被 轉印體上之光阻膜被曝光，爾後經過光阻的顯影步驟而形 成光阻圖案。因此，此灰階遮罩之半透光部的光強度分佈 係反映在被形成之光阻圖案的形狀上。此時，適當地選擇 光阻本身的感光度特性和顯影特性等，使用使上述光強度 分佈以充分的精度而反映在光阻圖案上的條件則是不言而 喻。 在此，作爲適用於本發明之灰階遮罩的曝光機，則具 有開口數NA爲0.1〜0_07左右的光學系統。 另一方面，第13圖係表示半透光部23之圖案形狀係 進一步微細化，寬度A成爲例如3.6am時的該半透光部之 透過光的光強度分佈。根據第1 3圖，光強度分佈曲線形狀 與第12圖不同，在峰値附近幾乎沒有平坦部。一般而言， 考慮到在和遮光部之邊界附近的半透光部中，按照曝光機 的解析度，藉由光的繞射而描繪既定的傾斜，但半透光部 之尺寸（寬度）縮小至例如6 // m以下時，因爲對曝光光線波 長和曝光機的解析度而言，繞射之影響會增大到無法忽略 的程度，成爲如第1 3圖所示幾乎無平坦部分的光強度分佈 形狀。因此，在被轉印體上之光阻膜被曝光且經過顯影步 驟而形成的光阻圖案上，轉印有幾乎無平坦部分之常態分 佈型的形狀。如這般’本發明者們發現，使用具有錐形狀 角度且幾乎沒有平坦部分的常態分佈型之形狀的光阻圖案 ，進行被轉印體之蝕刻時，藉由蝕刻而形成的圖案尺寸之 變化大，圖案的尺寸控制會非常困難，線寬精度會惡化。 -10- 200914989 此外’本發明者們也發現，這種問題會在半透光部之 爲6 μ m以下的時候產生，特別是在半透光部之寬度爲 4 A m時會很顯著。 因此，本發明者們硏討了迴避以往之藉由微細ϋ 由遮光膜所形成）而構成之半透光部的灰階遮罩中之 問題。亦即，硏討了使如上述第1 3圖的光強度分佈之 更陡斜上升的可能性。在此情況下，只要選擇微細圖 曝光條件，則在半透光部中，在某種程度上可能獲得 的光強度部分。但在此情況下，使半透光部的圖案微 時’透過光的光強度下降，將對被轉印體之光阻膜的 量設在恰當的範圍是很困難的。在此，適當的曝光量 以透過部作爲1 0 0 %的時候，在1 0〜7 0 %範圍內，該遮 用者之所需的曝光量。較佳爲20〜60 %，更佳爲30〜 範圍。因此，爲了獲得光強度，而擴大半透光部之圖 寸時，在曝光時進行解析，還是無法獲得平坦的光強 佈。因此需要降低解析度的曝光條件，但這會使圖案 印精度惡化。換言之，在以往的微細圖案型之灰階遮 ，半透光部之圖案的微細化和平坦的光強度分佈要兩 得是很困難的。 本發明是有鑑於上述習知之問題而完成者，其目 於提供一種灰階遮罩，其具備在半透光部中具有透過 光強度分佈爲平坦的部分，此外還能獲得既定之光強 半透光部。此外’本發明之目的在於提供一種高精度 階遮罩，其在將半透光部轉印至被轉印體之光阻膜的 寬度 S案（ 上述 傾斜 案和 平坦 細化 曝光 就是 罩使 ^ 60% 案尺 度分 的轉 罩中 者兼 的在 光之 度的 的灰 時候 -11 - 200914989 ，具有略一定膜厚的平坦部，並且形成所需之膜厚範圍的 光阻圖案。此外，目的在於提供一種圖案轉印方法，使用 本發明之灰階遮罩，即使半透光部的形狀微細化，也能以 進行高精度的圖案轉印。 爲了解決上述課題，本發明具有以下的構成。 (構成1) 一種灰階遮罩，在透明基板上具有半透光膜 以及遮光膜，並藉由在前述半透光膜以及前述遮光膜上分 別利用蝕刻而施加既定圖案，以形成遮光部、透光部以及 半透光部，該灰階遮罩之特徵爲：前述灰階遮罩係具有鄰 接並被前述遮光部包夾的半透光部，該半透光部係具有： 半透光膜形成部’係形成有半透光膜；以及透光縫隙部， 係設置在前述半透光部與鄰接之前述遮光部的邊界且露出 前述透明基板。 (構成2)如構成1所記載的灰階遮罩，其中，前述透 光縫隙部的寬度係相對於前述灰階遮罩，爲曝光條件之解 析極限以下的尺寸。 (構成3)如構成1或2所記載的灰階遮罩，其中，在 前述半透光膜形成部上形成不具有圖案的半透光膜。 (構成4)如構成1或2所記載的灰階遮罩，其中，前 述半透光膜形成部係相對於前述灰階遮罩，具有曝光光線 之解析極限以下的微細透光圖案。 (構成5)如構成1至4任一個所記載的灰階遮罩，其 中，前述灰階遮罩係用於曝光光源波長爲3 50nm〜450nm 範圍之波長域的灰階遮罩’前述半透光部的寬度係6/zm以 -12- 200914989 下。 (構成6)如構成5所記載的灰階遮罩，其中，前述半 透光部的寬度是l"m〜4//m。 (構成7) —種灰階遮罩，在透明基板上具有半透光膜 以及遮光膜，並藉由在前述半透光膜以及前述遮光膜上分 別利用独刻而施加既定圖案，以形成遮光部、透光部以及 半透光部，該灰階遮罩之特徵爲：前述灰階遮罩係具有鄰 接並被前述遮光部包夾的寬度A之半透光部，該半透光部 之寬度A爲6#m以下，相對於該半透光部，在包含波長 3 50nm〜45 Onm之範圍內的既定波長域之光的光透過強度 分佈曲線中，以前述透光部之曝光光線透過率作爲100%， 包含前述半透光部之寬度方向的中央部，以透過率變動爲 1 %以下的區域作爲灰階平坦部的時候，前述灰階平坦部之 寬度是超過寬度A之50%。 (構成8)如構成7所記載的灰階遮罩，其中，前述半 透光部具有在和鄰接之遮光部的邊界部分露出透明基板的 透光縫隙部。 (構成9)如構成8所記載的灰階遮罩，其中，前述透 光縫隙部的寬度係相對於前述灰階遮罩，爲曝光條件之解 析極限以下的尺寸。 (構成1 0) —種圖案轉印方法，其特徵爲具有以下步驟 :利用構成1至9中任一個記載之灰階遮罩，將圖案轉印 至設置在被轉印體上的光阻膜’在與前述半透光部對應之 部分上形成具有與前述遮光部或者透光部相異之光阻膜厚 -13- 200914989 部分的光阻圖案。 (構成11)—種圖案轉印方法，其特徵爲具有以下步驟 :利用構成1至9中任一個記載之灰階遮罩，藉由包含波 長350nm〜450nm之範圍內之波長的波長域之曝光光線來 曝光，將圖案轉印至設置在被轉印體上的光阻膜，在與前 述半透光部對應之部分上形成具有與前述遮光部或者透光 部相異之光阻膜厚部分的光阻圖案，前述光阻圖案係在與 前述灰階遮罩之寬度A的前述半透光部對應的部分中，與 前述透光部或者遮光部對應，以顯影後的光阻膜厚作爲 100% ’包含與前述半透光部對應之顯影後的光阻膜之寬度 方向的中央部，以膜厚變動爲1 %以下的區域作爲灰階平坦 部的時候，前述灰階平坦部之寬度是超過寬度A的50%。 藉由本發明之灰階遮罩，半透光部係具有形成有半透 光膜的半透光膜形成部、與前述半透光部所鄰接之遮光部 的邊界上設置之露出透明基板的透光縫隙部，能藉以提供 具備半透光部的灰階遮罩，該半透光部係在半透光部中具 有透過光之光強度分佈爲平坦的部分，此外還能獲得既定 之光強度。另外，藉由本發明之灰階遮罩，能提供一種高 精度的灰階遮罩，在將半透光部轉印至被轉印體之光阻膜 的時候，具有略一定膜厚的平坦部，並且形成所需之膜厚 範圍的光阻圖案。 此外，藉由使用本發明之灰階遮罩而對被轉印體進行 圖案轉印，即使半透光部的形狀微細化，也能進行高精度 的圖案轉印。 -14- 200914989 【實施方式】 以下基於圖面來說明用於實施本發明的最佳形態。 第1圖係表币本發明之灰階遮罩的一實施形態，第i(a) 圖係平面圖’而第1 (b)圖係沿著第1 (a)圖之l - L線的側截 面圖。第2圖係用於說明使用本發明之灰階遮罩的圖案轉 印方法之截面圖。 第丨圖所示的本發明之灰階遮罩3 0係用於製造例如液 晶顯示裝置（LCD)之薄膜電晶體（TFT)或彩色濾色片、或者 電漿顯示面板（P D P)’在第2圖所示之被轉印體4 0上，形 成膜厚爲階段性或連續性不同的光阻圖案4 3。此外，在第 2圖中，符號42A、42B係表示在被轉印體40中於基板41 上積層的膜。 具體而言，上述灰階遮罩30之構成爲具有：遮光部 3 1，在使用該灰階遮罩30時，遮蔽曝光光線（透過率約略 爲0 % );透光部3 2，約略1 00 %使曝光光線透過；以及半透 光部33，使曝光光線的透過率減低至20〜60%左右。半透 光部3 3之構成爲具有：半透光膜形成部3 3 a，在玻璃基板 等的透明基板3 4上形成半透光性之半透光膜3 6;以及透光 縫隙部3 3 b、3 3 c，設置在和半透光部3 3所鄰接之遮光部 3 1的邊界，並露出透明基板3 4。另外，遮光部31之構成 爲：在透明基板3 4上，設置遮光性的遮光膜3 5。此外’第 1圖所示之上述遮光部31、透光部32以及半透光部33的 圖案形狀當然是一個代表例’而非將本發明偈限於此。 作爲上述半透光膜36’則舉出鉻化合物、Mc)Sl、Sl、 -15- 200914989 W、A1。這當中’鉻化合物方面，則有氧化鉻（Cr〇x)、氮化 銘（CrNx)、氮氧化絡（Cr〇xN)、氟化鉻（CrFx)、或於這些含 有碳和氫者。另外，作爲遮光膜35，則舉出Cr、Si、w、 A1等。藉由選定遮光膜35之膜材質和膜厚來設定上述遮光 部31的透過率。另外，藉由選定半透光膜36之膜材質和 膜厚來設定上述半透光部33的透過率。 使用如同上述的灰階遮罩3 〇時，因爲曝光光線並無法 實質地在遮光部3丨透過，在半透光部33曝光光線被減低 ’所以被轉印體40上塗佈的光阻膜（正型光阻膜）係在與遮 光部3 1對應之部分膜厚會變厚，在與半透光部3 3對應之 部分膜厚會變薄，在與透光部3 2對應之部分則形成沒有膜 的光阻圖案43 (參照第2圖）。在此光阻圖案43中，將在與 半透光部3 3對應之部分膜厚會變薄的效果稱爲灰階效果 。此外’使用負型光阻的情況下，有必要進行考慮到與遮 光部和透光部對應之光阻膜厚會相反之情況的設計，但即 使在這種情況下，也能充分獲得本發明的效果。 然後’在第2圖所示光阻圖案43沒有膜的部分中，對 被轉印體40之例如膜42A以及42B實施第1蝕刻，藉由灰 化等來除去光阻圖案43之膜薄的部分，在此部分中，對被 轉印體40之例如膜42B實施第2蝕刻。以此方式，使用1 片灰階遮罩3 0就能實施以往之2片光罩的步驟，能減少遮 罩片數。 在此，更加詳細地說明本發明之上述灰階遮罩3 0的前 述半透光部3 3的構成時，在本實施形態中，前述半透光部 -16 - 200914989 33係與2個遮光部31、31鄰接而被夾持的半透光部，該半 透光部33係具有：半透光膜形成部33a，形成有半透光膜 36 ;以及透光縫隙部33b、33c，設置在該半透光膜形成部 3 3 a兩側，亦即與半透光部3 3鄰接之兩側的遮光部3 1、3 1 的邊界’且露出了透明基板34。 此透光縫隙部的寬度係相對於灰階遮罩30之曝光條 件的解析極限以下之尺寸，亦即依半透光部的設計尺寸所 決定，但一般太大時則不易獲得作爲半透光部的功能，太 小時則無法獲得光強度分佈的平坦部。具體而言，就6 # m 以下之寬度的半透光部而言，則是2//m以下，較佳是l/zm 以下0. 1 // m以上。在此情況下的曝光條件，就是曝光光源 波長、使用之曝光機的解析度等。本發明之灰階遮罩適合 用於曝光波長爲350nm〜450nm(i線至g線）者。 此外，作爲適用於本發明之灰階遮罩的曝光機，在具 有開口數NA具有0. 1〜0.07左右之光學系統的情況下，能 顯著地獲得本發明的效果。 此外，爲了在半透光部中，透過光線之光強度分佈具 有平坦之部分，較佳爲也考慮到相對於半透光部33之寬度 (設計値寬度）A(參照第1(b)圖）的透光縫隙部之寬度。亦即 ，相對於半透光部的寬度，當透光縫隙部的寬度太大時， 不易獲得作爲半透光部的功能，當太小時，就變得不易獲 得光強度分佈的平坦部。在透光縫隙部之寬度方面，較佳 爲單一側的寬度（33b或33c)爲（2/5)A以下（如果加上兩側之 寬度則是（4/5)A以下）。透光縫隙部（單一側）之寬度太大時 -17- 200914989 ，會因爲設置透光縫隙部，使得在半透光部中透過光線之 光強度分佈不會落在適當範圍內而不易獲得灰階效果。更 佳爲，在透光縫隙部之寬度方面，單一側的寬度（33b或3 3c) 爲（1/4)A以下（如果加上兩側之寬度則是（1/2)A以下）。因爲 縫隙部的寬度太小時，就不易獲得平坦的部分，所以單一 側（1/10)A (如果加上兩側之寬度則是（1/5)A)以上爲較佳。此 外，兩側之透光縫隙部33b與33c的寬度大略相同爲較佳 ，但只要不損及本發明之效果的話，也可以是不同。 另外，上述半透光膜形成部33a係由具有略均一之膜 厚的單一半透光膜36所形成。亦即，半透光膜形成部33a 之半透光膜3 6實質上沒有膜厚的分佈，且未施行微細圖案 加工。此半透光膜36係具有藉由在半透光部33求得之透 過率（半透過性）所決定的膜材質以及膜厚。 半透光膜的曝光光線透過率係在將透光部的透過率設 爲100%時，可設爲10〜70%，較佳爲20〜60%左右。 另一方面，上述半透光膜形成部33a上亦可施加曝光 光線相對於灰階遮罩30爲解析極限以下之微細的透光圖 案。亦即，在半透光膜形成部上亦可排列有複數個半透光 膜，分別具有藉由在半透光部求得之透過率所決定的尺寸 及膜材質以及膜厚。 在此，作爲第1具體範例，第3圖表示上述半透光部 33之寬度A爲3.6//m，將透光縫隙部33b和33c之寬度分 別作爲0.8 # m(因此，半透光膜形成部33a之寬度爲2.0 e m) 的半透光部33之灰階遮罩中，波長365nm〜436nm相對於 -18- 200914989 半透光部33的光透過強度分佈曲線。此外，半透光膜形成 部33a之半透光膜36的材質係作爲Cr氧化物並將膜厚調 整成爲透過率40%。 如第3圖所示，本發明之灰階遮罩在半透光部中具有 透過光之光強度分佈爲平坦的部分。在此，在半透光部中 具有透過光之光強度分佈爲平坦的部分就是指：對於寬度 A的半透光部，包含波長350nm〜450nm的範圍內之既定波 長域的光之光透過強度分佈曲線中，將前述透光部之曝光 光線透過率作爲100%，包含前述半透光部之寬度方向的中 央，將透過率變動爲1 %以下的區域作爲灰階平坦部的時候 ，前述灰階平坦部之寬度超過寬度A的5 0 %者。作爲比較 對象，前述第1 3圖係表示具備橫跨於夾在遮光部間的半透 光部之全體（整個寬度）上形成半透光膜，並將此半透光部 的寬度設爲3.6# m之半透光部的灰階遮罩之光透過強度分 佈曲線，爲了能瞭解與第1 3圖的對比，藉由本發明之灰階 遮罩’在半透光部之寬度爲6/zm以下的微細圖案中，在半 透光部中具有透過光之光強度分佈爲平坦的部分，此外且 能獲得既定的光強度，能獲得具備作爲本發明之目的半透 光部的灰階遮罩。 換言之’本發明之灰階遮罩係具有鄰接於前述遮光部 而被夾持之寬度A的半透光部，該半透光部之寬度a爲 6μιη以下’且具備一種半透光部，其中針對該半透光部， 在波長350nm〜450nm的光透過強度分佈曲線中，在包含前 述半透光部之寬度方向中央的A/2之寬度中，相對於光透 -19- 200914989 過強度之中央値而言，不均勻狀況爲光透過強度峰値的5 % 以內。 較佳爲半透光部的寬度是丨# m〜4 // m。特別能顯著地 獲得本發明之效果是在半透光部的寬度是2/zm〜4/zm的 情況下。 這種本發明的灰階遮罩之半透光部的光強度分佈也反 映在使用本發明之灰階遮罩，使被轉印體之光阻膜曝光並 歷經顯影步驟而形成的光阻圖案之形狀。亦即，使用本發 明之灰階遮罩，藉由包含350nm〜450nm之範圍內的既定波 長域的曝光光線來進行曝光，將圖案轉印至設在被轉印體 上的光阻膜，在與前述半透光部對應的部分，形成具有和 前述遮光部或者透光部不同之光阻膜厚部分的光阻圖案之 步驟的圖案轉印方法中，在本發明之灰階遮罩的寬度A之 與前述半透光部對應的部分中，將與前述透光部或者遮光 部對應之顯影後的光阻膜厚設爲100%，包含與前述半透光 部對應之顯影後的光阻膜之寬度方向之中央部’以膜厚變 動爲1 %以下之區域作爲灰階平坦部的時候，前述灰階平坦 部之寬度能形成超過寬度A之50%的光阻圖案。 因此，採用本發明之灰階遮罩，將半透光部轉印至被 轉印體之光阻膜時，能夠形成具有略一定膜厚之平坦部且 所需之膜厚範圍的光阻圖案，形成於被轉印體上的圖案之 尺寸變得容易控制，圖案的線寬精度提升。 另外，接著，作爲第2具體範例，於第4圖表示具有 上述半透光部33之寬度A爲5.4# m，在將透光縫隙部33b -20- 200914989 和33c的寬度分別設爲0.3 // m(因此’半透光膜形成部33a 的寬度是4.8/zm)之半透光部33的灰階遮罩中’對於半透 光部33之波長365nm〜436nm的光透過強度分佈曲線。此 外，半透光膜形成部33a之半透光膜36的材質和第1具體 範例的情況相同，將膜厚調整成透過率成爲40 %。另外， 於第5圖表示具備橫跨於以往被夾在遮光部間的半透光部 之全體（整個寬度）上形成半透光膜，並將此半透光部之寬 度設爲5.4^m之半透光部的灰階遮罩的光透過強度分佈曲 線。 比較第4圖（本發明）和第5圖（比較例）時，能明瞭到藉 由本發明，在半透光部之透過光的光強度分佈會在更大的 範圍（寬度）中具有平坦的部分。 從前述的第3圖和第1 3圖的對比以及上述的第4圖和 第5圖的對比中，可得知在包括曝光波長350nm〜450nm之 範圍內之既定波長域的曝光光線用的灰階遮罩中，鄰接於 遮光部而被夾持的半透光部之寬度爲6 # m以下的微細圖 案時’能獲得本發明的效果，特別是在上述半透光部之寬 度爲1〜4 // m時能顯著地獲得本發明的效果。 接著，參照第6圖以及第7圖，說明上述的灰階遮罩 之製造方法的一實施例。 第6圖以及第7圖係分別用於說明本發明之灰階遮罩 的製造步驟的截面圖以及平面圖。 使用的遮罩基底（mask blank)係在透明基板34上形成 遮光膜35(參照第6(a)圖）。遮光膜35的材質係使用Cr及 -21 - 200914989 其化合物的複合膜。 首先，在此遮罩基底之遮光膜35上塗佈光阻以形成光 阻膜。在描繪時，通常使用電子線或者光（短波長光）的情 況佔多數，但本實施例中則使用雷射光。因此’使用正型 光阻作爲上述光阻。然後’對光阻膜描繪既定的圖案（如同 形成與遮光部對應之光阻圖案的圖案）’描繪之後進行顯影 ，藉以形成與遮光部對應的光阻圖案3 7 a (參照第6 (b)圖）。 第7(a)圖就是以平面圖來表示此狀態者。 接著，將上述光阻圖案3 7 a作爲蝕刻遮罩，蝕刻遮光 膜3 5以形成遮光膜圖案3 5 a。因爲在本實施例中’在遮光 膜上使用Cr及其化合物的複合膜，所以作爲蝕刻手段，乾 式蝕刻或濕式蝕刻的任一者皆可。在本實施例中利用濕式 蝕亥[1。 除去殘存的光阻圖案37a之後（參照第6(c)圖），在基板 的全面上形成半透光膜36(參照第6(d)圖）。半透光膜36係 因爲相對於透明基板34之曝光光線的透過量’具有50〜20% 左右的透過量，在本實施例中，採用以濺鍍成膜而形成之 Cr氧化物（透過率40%)來作爲半透光膜36。 接著，在上述半透光膜36上形成和前述相同的光阻膜 ，進行第2次的描繪。第2次描繪中，描繪既定的圖案， 以形成半透光部3 3之與半透光膜形成部3 3 a對應的光阻圖 案。描繪後，藉由進行顯影，形成與半透光膜形成部33a 對應之光阻圖案37b(參照第6(e)圖）。 接著，將上述光阻圖案37b作爲蝕刻遮罩，蝕刻半透 -22- 200914989 光膜3 6 ’以形成構成半透光膜形成部3 3 a的半透光膜圖案 3 6 a。在本實施例中’作爲此情況下的蝕刻手段，在半透光 膜3 6和遮光膜3 5之間利用可獲得高蝕刻選擇性的乾式倉虫 刻。 然後’除去殘存的光阻圖案3 7 b，灰階遮罩3 0 (參照第 6 (f)圖）完成。第7 (b)圖係以平面圖來表示此狀態。 此外，本發明之灰階遮罩的製造方法並非被侷限於上 述實施例。在上述實施例中，使用在透明基板上形成遮光 膜的遮罩基底’在製造步驟之途中進行半透光膜的成膜， 但例如’也能使用在透明基板上依序形成半透光膜和遮光 膜之遮罩基底來製造。此情況下的遮光部係由半透光膜和 遮光膜之積層膜所構成。 明瞭若藉由本發明，除了上述說明的效果以外，相較 於以往之經形成由遮光膜所形成的微細圖案的半透光部（ 微細圖案型的灰階遮罩），在本發明中，半透光部的圖案（ 以年^透光膜所形成的半透光膜形成部）被容許之線寬範圍 寬廣’遮罩製作時的線寬管理容易。因此，在量產上有很 大的優點。 另外’藉由本發明，因爲不需要在元件製造時準備極 端高解析度（光NA)的曝光機，即使使用現行的曝光機，也 能充分應付TFT通道部的微細化，所以在元件製造方面是 很大的優點。 【圖式簡單說明】 第1圖係表示本發明之灰階遮罩的一實施形態，第1 (a) -23- 200914989 圖係平面圖，而第1(b)圖係沿著第1U)圖之L-L線的側截 面圖。 第2圖係用於說明使用本發明之灰階遮罩的圖案轉印 方法之截面圖。 第3圖係本發明之灰階遮罩針對半透光部分之波長 365nm〜436nm的光透過強度分佈曲線。 第4圖係本發明之灰階遮罩針對半透光部分之波長 365nm〜436nm的光透過強度分佈曲線。 第5圖係以往之半色調膜型之灰階遮罩的半透光部針 對波長365nm〜436nm的光透過強度分佈曲線。 第6(a)(b)(c)(d)(e)(f)圖係表示本發明之灰階遮罩的製 造步驟之一例的截面圖。 第7(a) (b)圖係用於說明本發明之灰階遮罩的製造步驟 之平面圖。 第8(1)(2)(3)圖係表示使用灰階遮罩之TFT基板的製 造步驟之槪略截面圖。 第9(1)(2)(3)圖係表示使用灰階遮罩之TFT基板的製 造步驟（第8圖的製造步驟的後續）之槪略截面圖。 第1 0圖係表示以往之微細圖案型的灰階遮罩之一例 的平面圖。 第1 1圖係表示以往之半色調膜型的灰階遮罩，第1 1 (a) 圖係平面圖，而第11(b)圖係沿著第li(a)圖之L-L線的側 截面圖。 第1 2圖係以往之半色調膜型之灰階遮罩的半透光部 -24- 200914989 針對波長3 6 5 n m〜4 3 6 n m的光透過強度分佈曲線。 第1 3圖係以往之半色調膜型之灰階遮罩的半透光部 針對波長3 65 nm〜43 6nm的光透過強度分佈曲線。 【主要元件符號說明】 1 玻 璃 基 板 2 閘 極 3 閘 絕 緣 膜 4 第 1 半 導體 膜 5 第 2 半 導體 膜 6 源 極 汲 極用 金屬膜 6a、6 b 源 極 /汲極 7 正 型 光 阻膜 7a 第 1 光 阻圖 案 7b 第 2 光 阻圖 案 10 灰 階 遮 罩 11' 11a 、lib 遮光部 12 透 光 部 13 半 透 光 部 13a 遮 光 圖 案 13b 透 過 部 20 灰 階 遮 罩 2 1 遮 光 部 22 透 光 部 23 半 透 光 部 24 透 明 基 板 -25- 200914989 25 遮 光 膜 26 半 透 光 膜 30 灰 階 遮 罩 3 1 遮 光 部 32 透 光 部 33 半 透 光 部 3 3a 半 透 光 膜 形 成部 33b、 33c 透 光 縫 隙 部 34 透 明 基 板 35 遮 光 膜 35a 遮 光 膜 圖 案 36 半 透 光 膜 36a 半 透 光 膜 圖 案 37a、 37b 光 阻 圖 案 40 被 轉 印 體 4 1 基 板 42 A ' 42B 膜 43 光 阻 圖 案 -26-[Technical Field] The present invention relates to a grayscale mask for manufacturing a photographic element, a liquid crystal display (hereinafter referred to as LCD), a semiconductor device, or the like, and the use of the opaque mask A pattern transfer method of a cover, in particular, a gray scale mask and a pattern transfer method used for a thin film transistor substrate (TFT substrate) suitable for use in manufacturing a thin film transistor liquid crystal display device. [Prior Art] Now, in the field of LC D, Thin Film Transistor Liquid Crystal Display (hereinafter referred to as TFT-LCD) is easier to thin than CRT (Cathode Wireline). Moreover, it has the advantage of low power consumption, so it is rapidly becoming commercialized. The TFT-LCD has a TFT substrate in which TFTs are arranged on each pixel arranged in a matrix, and a color filter in which a red, green, and blue pixel pattern is arranged corresponding to each pixel is attached to the liquid crystal layer. A strategic structure that intervenes and overlaps. In the TFT-LCD, the number of manufacturing steps is large, and it is necessary to use a 5 to 6 reticle for manufacturing a TFT substrate. In this case, in the "Flip Intelligence", May 999, P. 31 to 35 (Non-Patent Document 1), a method of manufacturing a TFT substrate using four photomasks has been proposed. This method reduces the number of masks used by using a photomask having a light-shielding portion, a light-transmitting portion, and a semi-transmissive portion (gray-scale portion) (hereinafter referred to as a gray scale mask). Here, the semi-transmissive portion means that when the mask is used and the pattern is transferred onto the transfer target, the amount of transmitted light transmitted through is reduced by a predetermined amount, and the photoresist film on the transfer target is controlled. The portion of the residual film amount after development, and 200914989, the mask having such a semi-transmissive portion, a light-shielding portion, and a light-transmitting portion is called a gray-scale mask. Figs. 8 and 9 (following the manufacturing steps of Fig. 8 and Fig. 8) show an example of a manufacturing procedure of a TFT substrate using a gray scale mask. A gate metal film is formed on the glass substrate 1, and the gate 2 is formed by a photolithography process using a photomask. Thereafter, the gate insulating film 3, the first semiconductor film 4 (a-Si), the second semiconductor film 5 (N + a-Si), the source-drain metal film 6, and the positive-type photoresist film 7 are formed (8th) (1) Figure). Next, using the gray scale mask 10 having the light shielding portion 11, the light transmitting portion 12, and the semi-light transmitting portion 13, the positive resist film 7 is exposed and developed, thereby forming the first photoresist pattern 7a so as to cover the TFT. The channel portion and the source drain formation region, the data transmission line formation region, and the channel portion formation region become thinner than the source drain formation region (Fig. 8(2)). Then, the source/deuterium metal film 6 and the second and first semiconductor films 5 and 4 are etched by using the first photoresist pattern 7a as a mask (Fig. 8(3)). Then, ashing is performed by oxygen to remove the photoresist film having a thin portion in the channel portion, and the second photoresist pattern 7b is formed (Fig. 9(1)). Then, the second photoresist pattern 7b is used as a mask, the source/deuterium metal film 6 is etched, the source/drain electrodes 6a and 6b are formed, and then the second semiconductor film 5 is etched (Fig. 9(2)). The remaining second photoresist pattern 7b is peeled off (Fig. 9(3)). As a gray scale mask which can be used here, a structure in which a semi-transmissive portion is formed in a fine pattern is known. For example, as shown in FIG. 10, the light-shielding portions 1 1 a and 1 1 b corresponding to the source/drain electrodes, the light-transmitting portion 1 2, and the semi-transmissive portion (gray-scale portion) corresponding to the channel portion 1 3. The semi-transmissive portion 13 forms a region of the 200914989 light pattern 13a which is composed of a fine pattern below the resolution limit of the exposure machine for LCD using a gray scale mask. The light shielding portions 11a, 11b and the light shielding pattern 13a are formed of the same thick film composed of the same material such as chromium and a chromium compound. In the case of the resolution limit portion of the exposure machine for LCDs using gray scale masks, the stepper type exposure machine is about 3 μm, and the mirror type exposure machine is about 4 # m. Therefore, for example, in the first diagram, the interval width of the transmissive portion 13b of the semi-transmissive portion 13 is set to be less than 3 μ, and the line width of the light-shielding pattern 13a is set to be 3 /i m below the analysis limit of the exposure machine. The semi-transparent portion of the above-described fine pattern type can be designed in consideration of the design of the step portion, and specifically, the fine pattern for making the intermediate halftone effect of the light portion having the light shielding portion be made into a line and a gap ( 1 ine space) type or dot (mesh) type, or other pattern selection. In addition, in the case of line and gap type, how to deal with the ratio of light transmission portion to shading portion, How much to design the overall rate, etc. On the other hand, Japanese Laid-Open Patent Publication No. 2002-189280 (Patent Literature) has previously proposed a portion to be subjected to halftone exposure as a semi-transmissive halftone film (semi-transmissive film). The film is used to reduce the exposure amount of the adjustment portion for halftone exposure. In the case of using the halftone condition, it is necessary to review how much the transmittance must be, and whether or not the mask is a film type (material) of a halftone film, The mask can be produced by selection. The film thickness control of the halftone film is performed when the mask is manufactured. Since the case where the TFT channel portion is formed by the gray scale portion of the gray scale mask is a halftone film, it can be easily used. The light lithography step is used to perform the large projection of the normal degree of the image, and the m' is less than the ash and the transparent, and the thickness of the halftone film is transparent. Next, the case is 200914989, so there is an advantage that even if the shape of the TFT channel portion is a complicated pattern shape. 1. The above semi - transparent portion is used as a half color. The above-mentioned gray-scale mask of the film-adjusting film (semi-transmissive film) is formed in a certain degree compared with the above-described gray pattern mask of the fine pattern type. It is very useful when the semi-transmissive portion of the above area is used. In the case of the semi-transmissive portion of the fine pattern type, there is a problem that the pattern data becomes swollen when the area is increased, but such a problem does not occur in the semi-transmissive portion using the halftone film. Fig. 11(a) shows an example of a gray scale mask in which such a semi-transmissive portion is used as a halftone film (semi-transmissive film). In other words, the grayscale mask 20 includes the light shielding portion 21, the light transmitting portion 22, and the semi-light transmitting portion 23 which are formed in a predetermined pattern, as shown in Fig. 1 (b) (along the first ( 1 (a) As shown in the cross-sectional view of the LL line, the light shielding portion 21 is configured to have a light shielding film 25 on the transparent substrate 24, the light transmission portion 22 is formed on a portion where the transparent substrate 24 is exposed, and the semi-light transmission portion 23 is configured as A semi-transmissive film 26 is provided on the transparent substrate 24. { i However, in recent years, especially with the miniaturization of the pattern of the TFT channel portion, more and more fine patterns are required in the gray scale mask, and the inventors have found that even in the case of using a semi-transparent film A new problem also occurs in the gray scale mask of the semi-transmissive portion. That is, for example, as shown in the above-mentioned second drawing, the half-transmission portion having a width Α of about 7 // m surrounded by the two light-shielding portions 21 and 21 of the light-shielding film 25 is formed by the semi-transmissive film 26. In the case of the gray scale mask of 2 3, the light intensity distribution of the transmitted light of the semi-transmissive portion of the exposure machine when the mask is used is as shown in FIG. Further, as the exposure light source of the exposure machine, a light source including a wavelength region of, for example, a g line (wavelength 4 3 6 n m) and an i line (wavelength 3 6 5 n m) of 200914989 3 5 0 n 4 4 5 5 n m is used. According to this light intensity distribution, the photoresist film on the transfer target is exposed, and then a photoresist step is formed through the development step of the photoresist. Therefore, the light intensity distribution of the semi-transmissive portion of the gray scale mask is reflected in the shape of the photoresist pattern to be formed. At this time, it is self-evident that the sensitivity characteristics and development characteristics of the photoresist itself are appropriately selected, and the conditions for reflecting the above-described light intensity distribution on the photoresist pattern with sufficient accuracy are used. Here, as an exposure machine suitable for the gray scale mask of the present invention, the number of openings NA is 0. Optical system from 1 to 0_07. On the other hand, Fig. 13 shows that the pattern shape of the semi-transmissive portion 23 is further refined, and the width A becomes, for example, 3. The light intensity distribution of the transmitted light of the semi-transmissive portion at 6 am. According to Fig. 13, the shape of the light intensity distribution curve is different from that of Fig. 12, and there is almost no flat portion near the peak. In general, in consideration of the semi-transmissive portion in the vicinity of the boundary between the light-shielding portion and the resolution of the exposure machine, the predetermined inclination is drawn by the diffraction of the light, but the size (width) of the semi-transmissive portion is reduced. When, for example, 6 // m or less, the influence of diffraction on the wavelength of the exposure light and the resolution of the exposure machine increases to such an extent that it cannot be ignored, and becomes light having almost no flat portion as shown in Fig. Strength distribution shape. Therefore, on the resist pattern formed by exposing the photoresist film on the object to be transferred and subjected to the developing step, a shape of a normal distribution type having almost no flat portion is transferred. As described above, the present inventors have found that the pattern size of the pattern formed by etching is performed when etching the object to be transferred using a photoresist pattern having a shape of a normal shape of a tapered shape and having almost no flat portion. Large, the size control of the pattern can be very difficult, and the line width accuracy will deteriorate. -10-200914989 Furthermore, the inventors have found that such a problem occurs when the semi-transmissive portion is 6 μm or less, particularly when the width of the semi-transmissive portion is 4 μm. Therefore, the inventors of the present invention have been asked to avoid the problem of the gray scale mask which is formed by the semi-transmissive portion which is formed by the fine ray by the light-shielding film. That is, there is a possibility that the light intensity distribution as shown in the above-mentioned Fig. 13 is steeply increased. In this case, as long as the fine pattern exposure condition is selected, the portion of the light intensity that is possible to some extent in the semi-transmissive portion is obtained. However, in this case, it is difficult to reduce the light intensity of the light transmitted through the pattern of the semi-transmissive portion by the amount of the light-transmitting film. Here, the appropriate exposure amount is the amount of exposure required by the occupant in the range of 10 to 70% when the transmission portion is 100%. It is preferably 20 to 60%, more preferably 30 to the range. Therefore, in order to obtain the light intensity and enlarge the image of the semi-transmissive portion, it is not possible to obtain a flat light intensity cloth when it is analyzed at the time of exposure. Therefore, it is necessary to lower the exposure conditions of the resolution, but this deteriorates the accuracy of the pattern printing. In other words, it is difficult to reduce the pattern of the semi-transmissive portion and the flat light intensity distribution in the conventional gray pattern of the fine pattern type. The present invention has been made in view of the above-mentioned problems, and it is an object of the invention to provide a gray scale mask having a portion having a flat light transmission intensity distribution in a semi-transmissive portion, and further obtaining a predetermined light intensity half. Light transmitting portion. Further, the object of the present invention is to provide a high-precision step mask which transfers the semi-transmissive portion to the width S of the photoresist film of the object to be transferred (the above-mentioned tilting case and flat refinement exposure are masks) 60% of the scales of the hood are also in the ash of the light degree -11 - 200914989, having a flat portion with a certain thickness, and forming a photoresist pattern of the desired film thickness range. In order to solve the above problems, the present invention has the following configuration in order to solve the above problems by using the gray scale mask of the present invention, even if the shape of the semi-transmissive portion is made fine. (Configuration 1) A gray-scale mask having a semi-transmissive film and a light-shielding film on a transparent substrate, and applying a predetermined pattern by etching on the semi-transmissive film and the light-shielding film, respectively, to form a light-shielding portion, The light-transmitting portion and the semi-transmissive portion are characterized in that the gray-scale mask has a semi-transmissive portion adjacent to and sandwiched by the light-shielding portion, and the semi-transmissive portion has: semi-transparent portion Membrane shape The portion is formed with a semi-transmissive film; and the light-transmissive slit portion is provided at a boundary between the semi-transmissive portion and the adjacent light-shielding portion to expose the transparent substrate. (Configuration 2) The gray scale described in the configuration 1 In the mask, the width of the light-transmitting slit portion is equal to or smaller than the analysis limit of the exposure condition with respect to the gray-scale mask. (Configuration 3) The gray-scale mask according to the configuration 1 or 2, wherein A semi-transmissive film having no pattern is formed on the semi-transmissive film forming portion. (Configuration 4) The gray-scale mask according to the first or second aspect, wherein the semi-transmissive film forming portion is opposed to the ash The step mask has a fine light transmissive pattern of the exposure light ray, and the gray scale mask according to any one of the first to fourth aspects, wherein the gray scale mask is used for the exposure light source wavelength. 3, the gray-scale mask of the wavelength range of 50 nm to 450 nm, the width of the semi-transmissive portion is 6/zm, and is -12-200914989. (Configuration 6) The gray-scale mask according to the configuration 5, wherein the foregoing The width of the semi-transmissive portion is l"m~4//m. (Structure 7) - Gray scale a cover having a semi-transmissive film and a light-shielding film on a transparent substrate, and applying a predetermined pattern by using a unique pattern on the semi-transmissive film and the light-shielding film, respectively, to form a light-shielding portion, a light-transmitting portion, and a semi-transparent light. The gray-scale mask is characterized in that the gray-scale mask has a semi-transmissive portion having a width A adjacent to and sandwiched by the light-shielding portion, and the width A of the semi-transmissive portion is 6#m or less. In the semi-transmissive portion, in the light transmission intensity distribution curve of light in a predetermined wavelength range including a wavelength of 3 50 nm to 45 Onm, the exposure light transmittance of the light transmitting portion is 100%, and the semi-transparent portion is included. In the central portion in the width direction of the light portion, when the region where the transmittance variation is 1% or less is used as the gray scale flat portion, the width of the gray scale flat portion exceeds 50% of the width A. In the gradation mask of the seventh aspect, the semi-transmissive portion has a light-transmissive slit portion exposing the transparent substrate at a boundary portion with the adjacent light-shielding portion. (Aspect 9) The gray scale mask according to the eighth aspect, wherein the width of the light-transmitting slit portion is equal to or smaller than a resolution limit of exposure conditions with respect to the gray scale mask. (Form 10) A pattern transfer method characterized by the step of transferring a pattern to a photoresist film provided on a transfer target by using a gray scale mask described in any one of Compositions 1 to 9. A photoresist pattern having a portion of the photoresist film thickness -13 - 200914989 different from the light shielding portion or the light transmitting portion is formed on a portion corresponding to the semi-transmissive portion. (Structure 11) A pattern transfer method characterized by having the following steps: using the gray scale mask described in any one of 1 to 9 by exposure in a wavelength range including a wavelength in a wavelength range of 350 nm to 450 nm Exposing light to the photoresist film disposed on the transfer target, and forming a photoresist film thickness portion different from the light shielding portion or the light transmitting portion on a portion corresponding to the semi-transmissive portion In the photoresist pattern, the photoresist pattern corresponds to the light transmissive portion or the light shielding portion in a portion corresponding to the semi-transmissive portion of the width A of the gray scale mask, and the photoresist film thickness after development is used as a resist pattern. 100%' includes a central portion in the width direction of the developed photoresist film corresponding to the semi-transmissive portion, and a width of the gray-scale flat portion when a region having a film thickness variation of 1% or less is used as a gray-scale flat portion It is more than 50% of the width A. According to the gray scale mask of the present invention, the semi-transmissive portion has a semi-transmissive film forming portion in which a semi-transmissive film is formed, and a transparent substrate which is provided on the boundary of the light-shielding portion adjacent to the semi-transmissive portion. The optical slit portion can provide a gray-scale mask having a semi-transmissive portion having a portion in which the light intensity distribution of the transmitted light is flat in the semi-transmissive portion, and a predetermined light intensity can be obtained. . Further, according to the gray scale mask of the present invention, it is possible to provide a high-precision gray scale mask having a flat portion having a certain thickness when transferring the semi-transmissive portion to the photoresist film of the transfer target body. And forming a photoresist pattern of a desired film thickness range. Further, by transferring the transfer target by the use of the gray scale mask of the present invention, high-precision pattern transfer can be performed even if the shape of the semi-transmissive portion is made fine. -14-200914989 [Embodiment] Hereinafter, the best mode for carrying out the invention will be described based on the drawings. Figure 1 is an embodiment of the grayscale mask of the present invention, the i-th (a) is a plan view 'and the first (b) is along the side of the l-L line of the first (a) Sectional view. Fig. 2 is a cross-sectional view for explaining a pattern transfer method using the gray scale mask of the present invention. The grayscale mask 30 of the present invention shown in the figure is used to manufacture a thin film transistor (TFT) or a color filter, or a plasma display panel (PDP), for example, a liquid crystal display device (LCD). In the transfer-receiving body 40 shown in Fig. 2, a photoresist pattern 43 having a film thickness different in phase or continuity is formed. Further, in Fig. 2, reference numerals 42A and 42B denote films laminated on the substrate 41 in the transfer target body 40. Specifically, the grayscale mask 30 is configured to have a light shielding portion 31, and when the grayscale mask 30 is used, the exposure light is shielded (the transmittance is approximately 0%); the light transmitting portion 3 2 is approximately 1 00% transmits the exposure light; and the semi-transmissive portion 33 reduces the transmittance of the exposure light to about 20 to 60%. The semi-transmissive portion 3 3 has a semi-transmissive film forming portion 3 3 a, a semi-transmissive semi-transmissive film 36 formed on a transparent substrate 34 such as a glass substrate, and a light transmissive slit portion 3 3 b, 3 3 c are provided at the boundary of the light shielding portion 31 adjacent to the semi-transmissive portion 33, and the transparent substrate 34 is exposed. Further, the light shielding portion 31 is configured such that a light-shielding light-shielding film 35 is provided on the transparent substrate 34. Further, the pattern shape of the light shielding portion 31, the light transmitting portion 32, and the semi-light transmitting portion 33 shown in Fig. 1 is of course a representative example, and the present invention is not limited thereto. Examples of the semi-transmissive film 36' include a chromium compound, Mc)Sl, Sl, -15-200914989 W, and A1. Among the 'chromium compounds', there are chromium oxide (Cr〇x), nitriding (CrNx), oxynitride (Cr〇xN), chromium fluoride (CrFx), or those containing carbon and hydrogen. Moreover, as the light shielding film 35, Cr, Si, w, A1, etc. are mentioned. The transmittance of the light shielding portion 31 is set by selecting the film material and film thickness of the light shielding film 35. Further, the transmittance of the semi-transmissive portion 33 is set by selecting the film material and film thickness of the semi-transmissive film 36. When the gray scale mask 3 is used as described above, since the exposure light is not substantially transmitted through the light shielding portion 3, the exposure light is reduced in the semi-transmissive portion 33, so the photoresist film coated on the transfer body 40 is applied. The (positive-type resist film) is thicker in a portion corresponding to the light-shielding portion 31, and is thinner in a portion corresponding to the semi-transmissive portion 33, and corresponds to the portion corresponding to the light-transmitting portion 32. Then, a photoresist pattern 43 having no film is formed (refer to FIG. 2). In the photoresist pattern 43, the effect of thinning the portion of the film corresponding to the semi-transmissive portion 33 is referred to as a gray scale effect. In addition, in the case of using a negative-type photoresist, it is necessary to design a case where the thickness of the photoresist film corresponding to the light-shielding portion and the light-transmitting portion is reversed, but even in this case, the present invention can be sufficiently obtained. Effect. Then, in the portion where the photoresist pattern 43 has no film as shown in Fig. 2, for example, the films 42A and 42B of the transfer target 40 are subjected to the first etching, and the film of the photoresist pattern 43 is removed by ashing or the like. In this section, for example, the film 42B of the transfer target 40 is subjected to the second etching. In this way, the steps of the conventional two-piece mask can be implemented by using one grayscale mask 30, which can reduce the number of masks. Here, in the case where the configuration of the semi-transmissive portion 33 of the above-described gray-scale mask 30 of the present invention is described in more detail, in the present embodiment, the semi-transmissive portion -16 - 200914989 33 and two shading portions are provided. a semi-transmissive portion that is sandwiched by the portions 31 and 31, the semi-transmissive portion 33 having a semi-transmissive film forming portion 33a formed with a semi-transmissive film 36, and transparent slit portions 33b and 33c. The transparent substrate 34 is exposed on both sides of the semi-transmissive film forming portion 3 3 a, that is, the boundary between the light-shielding portions 31 and 31 on both sides adjacent to the semi-transmissive portion 33. The width of the light-transmissive slit portion is determined according to the size below the resolution limit of the exposure condition of the gray-scale mask 30, that is, the design size of the semi-transmissive portion, but when it is too large, it is difficult to obtain as a semi-transparent light. The function of the part is too small to obtain a flat portion of the light intensity distribution. Specifically, the semi-transmissive portion having a width of 6 # m or less is 2/m or less, preferably 0/zm or less. 1 // m or more. The exposure conditions in this case are the wavelength of the exposure light source, the resolution of the exposure machine used, and the like. The gray scale mask of the present invention is suitable for use in an exposure wavelength of 350 nm to 450 nm (i line to g line). Further, as an exposure machine suitable for the gray scale mask of the present invention, the number of openings NA has 0. 1~0. In the case of an optical system of about 07, the effects of the present invention can be remarkably obtained. Further, in order to have a flat portion of the light intensity distribution of the transmitted light in the semi-transmissive portion, it is preferable to consider the width (design width) A with respect to the semi-transmissive portion 33 (refer to Fig. 1(b)). The width of the light transmissive slit portion. That is, with respect to the width of the semi-transmissive portion, when the width of the light-transmitting slit portion is too large, the function as a semi-transmissive portion is not easily obtained, and when it is too small, it becomes difficult to obtain a flat portion of the light intensity distribution. In terms of the width of the light-transmitting slit portion, it is preferable that the width (33b or 33c) of the single side is (2/5) A or less ((4/5) A or less if the width of both sides is added). When the width of the light-transmissive slit portion (single side) is too large, -17-200914989, because the light-transmitting slit portion is provided, the light intensity distribution of the transmitted light in the semi-transmissive portion does not fall within an appropriate range, and the gray is not easily obtained. Order effect. More preferably, the width (33b or 3 3c) of the single side is (1/4) A or less in the width of the light-transmissive slit portion ((1/2) A or less if the width of both sides is added). Since the width of the slit portion is too small, it is difficult to obtain a flat portion, so that it is preferable that the single side (1/10) A (if the width of both sides is (1/5) A) is preferable. Further, it is preferable that the widths of the light-transmitting slit portions 33b and 33c on both sides are substantially the same, but they may be different as long as the effects of the present invention are not impaired. Further, the semi-transmissive film forming portion 33a is formed of a single-half transparent film 36 having a slightly uniform film thickness. That is, the semi-transmissive film 36 of the semi-transmissive film forming portion 33a has substantially no film thickness distribution, and fine pattern processing is not performed. The semi-transmissive film 36 has a film material and a film thickness which are determined by the transmittance (semi-transmissivity) obtained in the semi-transmissive portion 33. The light transmittance of the semi-transmissive film can be set to 10 to 70%, preferably about 20 to 60%, when the transmittance of the light transmitting portion is 100%. On the other hand, the semi-transmissive film forming portion 33a may be provided with a fine light transmissive pattern in which the exposure light is equal to or lower than the resolution limit of the gray scale mask 30. That is, a plurality of semi-transmissive films may be arranged on the semi-transmissive film forming portion, and each has a size, a film material, and a film thickness which are determined by the transmittance obtained in the semi-transmissive portion. Here, as a first specific example, Fig. 3 shows that the width A of the semi-transmissive portion 33 is 3. 6//m, the widths of the light-transmitting slit portions 33b and 33c are taken as 0. 8 # m (hence, the width of the semi-transmissive film forming portion 33a is 2. In the gray scale mask of the semi-transmissive portion 33 of 0 e m), the light transmission intensity distribution curve of the semi-transmissive portion 33 with respect to the wavelength of 365 nm to 436 nm with respect to -18-200914989. Further, the material of the semi-transmissive film 36 of the semi-transmissive film forming portion 33a is made of Cr oxide and the film thickness is adjusted to have a transmittance of 40%. As shown in Fig. 3, the gray scale mask of the present invention has a portion in which the light intensity distribution of the transmitted light is flat in the semi-transmissive portion. Here, the portion having the light intensity distribution of the transmitted light in the semi-transmissive portion is a light transmissive intensity of the light having a predetermined wavelength range in the range of 350 nm to 450 nm for the semi-transmissive portion having the width A. In the distribution curve, when the light transmittance of the light-transmitting portion is 100%, the center of the semi-transmissive portion in the width direction is included, and the region where the transmittance is changed to 1% or less is used as the gray-scale flat portion, the gray The width of the step flat portion exceeds 50% of the width A. As a comparison object, the first three-third figure shows that a semi-transmissive film is formed over the entire half width of the semi-transmissive portion sandwiched between the light-shielding portions, and the width of the semi-transmissive portion is set to three. . The light transmission intensity distribution curve of the gray scale mask of the semi-transmissive portion of 6# m, in order to understand the comparison with the first graph, the width of the gray-scale mask 'in the semi-transmissive portion of the present invention is 6/ In the fine pattern of zm or less, the semi-transmissive portion has a portion in which the light intensity distribution of the transmitted light is flat, and a predetermined light intensity can be obtained, and the gray scale cover having the semi-transmissive portion as the object of the present invention can be obtained. cover. In other words, the gray-scale mask of the present invention has a semi-transmissive portion having a width A that is sandwiched between the light-shielding portions, and has a width a of 6 μm or less and a semi-transmissive portion. In the light transmission intensity distribution curve having a wavelength of 350 nm to 450 nm, the width of the A/2 including the center of the semi-transmissive portion in the width direction is excessive with respect to the light transmission -19-200914989. For the central ridge, the unevenness is within 5% of the peak of the light transmission intensity. Preferably, the width of the semi-transmissive portion is 丨#m~4 // m. In particular, it is remarkable that the effect of the present invention is that the width of the semi-transmissive portion is 2/zm 4 /zm. The light intensity distribution of the semi-transmissive portion of the gray scale mask of the present invention is also reflected in the resist pattern formed by exposing the photoresist film of the transfer target and performing the development step using the gray scale mask of the present invention. The shape. That is, using the gray scale mask of the present invention, the exposure is performed by exposure light including a predetermined wavelength range in the range of 350 nm to 450 nm, and the pattern is transferred to the photoresist film provided on the transfer target body. a pattern transfer method of forming a photoresist pattern having a photoresist film thickness portion different from the light shielding portion or the light transmitting portion in a portion corresponding to the semi-transmissive portion, in the width of the gray scale mask of the present invention In the portion corresponding to the semi-transmissive portion of A, the developed resistive film thickness corresponding to the light transmitting portion or the light blocking portion is set to 100%, and the developed photoresist corresponding to the semi-transmissive portion is included. When the region at the center portion in the width direction of the film has a film thickness variation of 1% or less as the gray scale flat portion, the width of the gray scale flat portion can form a photoresist pattern exceeding 50% of the width A. Therefore, when the semi-transmissive portion is transferred to the photoresist film of the transfer target by the gray scale mask of the present invention, a photoresist pattern having a flat portion having a certain film thickness and a desired film thickness range can be formed. The size of the pattern formed on the transfer target body is easily controlled, and the line width precision of the pattern is improved. Further, as a second specific example, the width A having the semi-transmissive portion 33 is 5. 4# m, the widths of the light-transmissive slit portions 33b -20- 200914989 and 33c are respectively set to 0. 3 // m (so the width of the semi-transmissive film forming portion 33a is 4. In the gray scale mask of the semi-transmissive portion 33 of 8/zm), the light transmission intensity distribution curve for the wavelength of the semi-transmissive portion 33 of 365 nm to 436 nm. Further, the material of the semi-transmissive film 36 of the semi-transmissive film forming portion 33a is the same as in the case of the first specific example, and the film thickness is adjusted so that the transmittance becomes 40%. Further, in Fig. 5, a semi-transmissive film is formed over the entire half width of the semi-transmissive portion sandwiched between the light-shielding portions, and the width of the semi-transmissive portion is set to 5. The light transmission intensity distribution curve of the gray scale mask of the semi-transmissive portion of 4^m. Comparing Fig. 4 (present invention) and Fig. 5 (comparative example), it can be understood that by the present invention, the light intensity distribution of the transmitted light in the semi-transmissive portion is flat in a larger range (width). section. From the comparison of the aforementioned FIGS. 3 and 13 and the comparison of the above-mentioned FIG. 4 and FIG. 5, it is possible to know the ash for the exposure light in a predetermined wavelength range including the exposure wavelength of 350 nm to 450 nm. In the step mask, when the width of the semi-transmissive portion sandwiched between the light-shielding portions is 6 μm or less, the effect of the present invention can be obtained, and in particular, the width of the semi-transmissive portion is 1 to 1 The effect of the present invention can be remarkably obtained at 4 // m. Next, an embodiment of the above-described method of manufacturing a gray scale mask will be described with reference to Figs. 6 and 7. Fig. 6 and Fig. 7 are a cross-sectional view and a plan view, respectively, for explaining the manufacturing steps of the gray scale mask of the present invention. The mask blank used is a light-shielding film 35 formed on the transparent substrate 34 (see Fig. 6(a)). The material of the light-shielding film 35 is a composite film of a compound of Cr and -21 - 200914989. First, a photoresist is applied on the light shielding film 35 of the mask substrate to form a photoresist film. At the time of drawing, electron beam or light (short-wavelength light) is usually used, but in the present embodiment, laser light is used. Therefore, a positive photoresist is used as the above photoresist. Then, 'the photoresist pattern is drawn with a predetermined pattern (as in the pattern forming the photoresist pattern corresponding to the light-shielding portion), and then developed, thereby forming a photoresist pattern 3 7 a corresponding to the light-shielding portion (refer to 6 (b) Figure). Figure 7(a) is a diagram showing the state in a plan view. Next, the photoresist pattern 3 7 a is used as an etching mask, and the light-shielding film 35 is etched to form a light-shielding film pattern 35 5 a. In the present embodiment, a composite film of Cr and a compound thereof is used on the light-shielding film, and any of dry etching or wet etching may be used as the etching means. In the present embodiment, wet etching [1] is utilized. After the remaining photoresist pattern 37a is removed (see Fig. 6(c)), the semi-transmissive film 36 is formed over the entire substrate (see Fig. 6(d)). The semi-transmissive film 36 has a permeation amount of about 50 to 20% due to the amount of penetration of the exposure light with respect to the transparent substrate 34. In the present embodiment, Cr oxide formed by sputtering deposition is used (transmission ratio). 40%) comes as the semi-transmissive film 36. Next, the same photoresist film as described above was formed on the semi-transmissive film 36, and the second drawing was performed. In the second drawing, a predetermined pattern is drawn to form a photoresist pattern corresponding to the semi-transmissive film forming portion 3 3 a of the semi-transmissive portion 33. After the drawing, the resist pattern 37b corresponding to the semi-transmissive film forming portion 33a is formed by development (see FIG. 6(e)). Next, the photoresist pattern 37b is used as an etching mask, and the semitransparent film pattern 3 6 a constituting the semi-transmissive film forming portion 3 3 a is formed by etching the translucent film -22-200914989. In the present embodiment, as the etching means in this case, a dry smear which can obtain high etching selectivity is utilized between the semi-transmissive film 36 and the light-shielding film 35. Then, the remaining photoresist pattern 3 7 b is removed, and the gray scale mask 30 (refer to Fig. 6 (f)) is completed. Figure 7 (b) shows this state in a plan view. Further, the method of manufacturing the gray scale mask of the present invention is not limited to the above embodiment. In the above embodiment, the mask substrate 'forming the light-shielding film on the transparent substrate is used to form a semi-transmissive film on the way of the manufacturing step, but for example, a semi-transparent film may be sequentially formed on the transparent substrate. It is manufactured with a mask base of a light-shielding film. The light shielding portion in this case is composed of a laminated film of a semi-transmissive film and a light-shielding film. According to the present invention, in addition to the effects described above, in the present invention, half of the semi-transmissive portion (fine pattern type gray scale mask) formed by the fine pattern formed by the light shielding film is used. The pattern of the light-transmitting portion (the semi-transmissive film forming portion formed by the light-transmissive film) is allowed to have a wide line width range. The line width management at the time of mask production is easy. Therefore, there are great advantages in mass production. In addition, according to the present invention, since it is not necessary to prepare an exposure machine of extremely high resolution (light NA) at the time of component manufacture, even if the current exposure machine is used, the miniaturization of the TFT channel portion can be sufficiently coped with, and therefore, in terms of component manufacturing, Great advantage. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an embodiment of a gray scale mask of the present invention, the first (a) -23- 200914989 diagram is a plan view, and the first (b) diagram is along the first U) diagram. A side cross-sectional view of the LL line. Fig. 2 is a cross-sectional view for explaining a pattern transfer method using the gray scale mask of the present invention. Fig. 3 is a light transmission intensity distribution curve of the gray scale mask of the present invention for a wavelength of 365 nm to 436 nm for the semi-transmissive portion. Fig. 4 is a light transmission intensity distribution curve of the gray scale mask of the present invention for a wavelength of 365 nm to 436 nm for the semi-transmissive portion. Fig. 5 is a light transmission intensity distribution curve of a semi-transmissive portion of a conventional halftone film type gray scale mask for a wavelength of 365 nm to 436 nm. Fig. 6(a)(b)(c)(d)(e)(f) is a cross-sectional view showing an example of a manufacturing step of the gray scale mask of the present invention. Fig. 7(a)(b) is a plan view for explaining the manufacturing steps of the gray scale mask of the present invention. The eighth (1), (2), and (3) drawings are schematic cross-sectional views showing the steps of manufacturing the TFT substrate using the gray scale mask. The ninth (1), (2) and (3) drawings are schematic cross-sectional views showing the manufacturing steps (following the manufacturing steps of Fig. 8) of the TFT substrate using the gray scale mask. Fig. 10 is a plan view showing an example of a conventional fine pattern type gray scale mask. Fig. 1 is a view showing a conventional halftone film type gray scale mask, the first 1 (a) diagram is a plan view, and the 11th (b) diagram is a side section along the LL line of the lith (a) diagram. Figure. Fig. 1 is a semi-transmissive portion of a conventional halftone film type gray scale mask -24- 200914989 for a light transmission intensity distribution curve of a wavelength of 3 6 5 n m to 4 3 6 n m. Fig. 1 is a semi-transmissive portion of a conventional halftone film type gray scale mask for a light transmission intensity distribution curve at a wavelength of 3 65 nm to 43 6 nm. [Description of main component symbols] 1 Glass substrate 2 Gate 3 Gate insulating film 4 First semiconductor film 5 Second semiconductor film 6 Source film for source drain electrodes 6a, 6b Source/drain 7 Positive-type resist film 7a First photoresist pattern 7b Second photoresist pattern 10 Gray scale mask 11' 11a, lib Shading portion 12 Light transmitting portion 13 Semi-light transmitting portion 13a Light blocking pattern 13b Transmissive portion 20 Gray scale mask 2 1 Light blocking portion 22 Light transmission Part 23 Semi-transmissive portion 24 Transparent substrate - 25 - 200914989 25 Light-shielding film 26 Semi-transmissive film 30 Gray-scale mask 3 1 Light-shielding portion 32 Light-transmitting portion 33 Semi-transmissive portion 3 3a Semi-transmissive film forming portion 33b, 33c Light-transmissive slit portion 34 Transparent substrate 35 Light-shielding film 35a Light-shielding film pattern 36 Semi-transmissive film 36a Semi-transmissive film pattern 37a, 37b Photoresist pattern 40 Transfer body 4 1 Substrate 42 A '42B Film 43 Resistive pattern -26 -