TW201830173A - 處理裝置及用於校正橫跨基板的參數變化的方法 - Google Patents
處理裝置及用於校正橫跨基板的參數變化的方法 Download PDFInfo
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Abstract
一種基板處理裝置,其包含: 一基板裝載器件,其經組態以在相對於與一基板上之場之一佈局相關聯的一柵格之一預定定向上裝載該基板; 校正性元件,其等經組態以使得能夠局域校正對一基板執行之一程序之一特性;其特徵在於 該等校正性元件經配置成沿著具有除了平行於該柵格之X軸或Y軸以外之一方向之至少一個軸線。
Description
本發明係關於器件製造,且詳言之係關於改良微影程序之良率。
微影裝置為將所要圖案施加至基板上(通常施加至基板之目標部分上)之機器。微影裝置可用於例如積體電路(IC)之製造中。在彼情況下,圖案化器件(其替代地被稱為光罩或倍縮光罩)可用以產生待形成於IC之個別層上的電路圖案。此圖案可轉印至基板(例如,矽晶圓)上之目標部分(例如包括晶粒之部分、一個晶粒或若干晶粒)上。通常經由成像至提供於基板上之輻射敏感材料(抗蝕劑)層上來進行圖案之轉印。一般而言,單一基板將含有經順次地圖案化之鄰近目標部分之網路。 在微影程序中,頻繁地需要對所產生結構進行量測,例如,用於程序控制及驗證。用於進行此類量測之各種工具已知,包括:常常用於量測臨界尺寸(CD)之掃描電子顯微鏡;量測疊對——器件中兩個層之對準準確度——之特殊化工具;以及可量測經圖案化基板之各種屬性之散射計。 在量測橫跨基板之諸如CD之屬性的情況下,已知程序最佳化技術調整待對該基板或其他基板實行之曝光或程序步驟之相關參數以便校正或補償彼屬性之任何誤差。然而,此途徑不能夠始終充分校正或補償誤差。
本發明旨在改良微影裝置製造程序中之良率。 本發明在一第一態樣中提供一種基板處理裝置,其包含: 一基板裝載器件,其經組態以在相對於與一基板上之場之一佈局相關聯的一柵格之一預定定向上裝載該基板; 校正性元件,其等經組態以使得能夠局域校正對一基板執行之一程序之一特性;其特徵在於該等校正性元件經配置成沿著具有除了平行於該柵格之X軸或Y軸以外之一方向之至少一個校正軸線。 本發明在一第二態樣中提供一種器件製造程序,其包含: 使用一微影裝置將一圖案曝光至一基板上之場之一柵格上; 使用校正性元件之一柵格將該基板輸送至一處理工具; 定向該基板使得場之該柵格相對於校正性元件之該柵格成一預定角度;及 使用該處理工具將該圖案轉印至該基板中。
在詳細地描述本發明之實施例之前,呈現可供實施本發明之實施例的實例環境為具指導性的。 圖1說明半導體生產設施之典型佈局。微影裝置100將所要圖案施加至基板上。微影裝置係用於例如積體電路(IC)之製造中。在彼情況下,圖案化器件(其被替代地稱作光罩或倍縮光罩)包含待形成於IC之個別層上之特徵(常常被稱作「產品特徵」)之電路圖案。此圖案經由將圖案化器件曝光104至提供於基板上之輻射敏感材料(抗蝕劑)層上而轉印至基板「W」(例如矽晶圓)上之目標部分(例如,包含晶粒之部分、一個晶粒或若干晶粒)上。一般而言,單一基板將含有經順次地圖案化之鄰近目標部分之網路。 已知微影裝置藉由照明圖案化器件,同時同步地將基板之目標部分定位在圖案化器件之影像位置處而輻照每一目標部分。基板之經輻照目標部分被稱作「曝光場」或僅被稱作「場」。基板上之場之佈局通常為根據笛卡爾(Cartesian)二維座標系統對準(例如,沿著X軸及Y軸對準,兩條軸線彼此正交)之鄰近矩形之網路。 對微影裝置之要求為所要圖案至基板上之準確再現。所施加之產品特徵之位置及尺寸需要在特定容限內。位置誤差可歸因於疊對誤差(常常被稱作「疊對」)而出現。疊對為相對於第二層內之第二產品特徵而置放第一層內之第一產品特徵時的誤差。微影裝置藉由在圖案化之前將各晶圓與參考準確地對準而使疊對誤差最小化。藉由量測施加至基板之對準標記之位置而進行此操作。基於對準量測,在圖案化程序期間控制基板位置以便防止疊對誤差之出現。 產品特徵之臨界尺寸(CD)之誤差可在與曝光104相關聯的施加劑量並不在規格內時出現。出於此原因,微影裝置100必須能夠準確地控制施加至基板之輻射之劑量。CD誤差亦可在基板並未相對於與圖案影像相關聯的焦平面正確地定位時出現。焦點位置誤差通常與基板表面之非平面度相關聯。微影裝置藉由在圖案化之前使用位階感測器量測基板表面構形而使此等焦點位置誤差最小化。在後續圖案化期間施加基板高度校正以確保圖案化器件至基板上之正確成像(聚焦)。 為了驗證與微影程序相關聯的疊對及CD誤差,藉由度量衡裝置140檢測經圖案化基板。度量衡裝置之常見實例為散射計。散射計習知地量測專用度量衡目標之特性。此等度量衡目標表示產品特徵,惟其尺寸通常較大以便允許準確量測除外。散射計藉由偵測與疊對度量衡目標相關聯的繞射圖案之不對稱性而量測疊對。藉由對與CD度量衡目標相關聯的繞射圖案之分析而量測臨界尺寸。度量衡工具之另一實例為基於電子束(e-beam)之檢測工具,諸如掃描電子顯微鏡(SEM)。 在半導體生產設施內,微影裝置100及度量衡裝置140形成「微影製造單元」或「微影叢集」之部分。微影叢集亦包含用於將感光抗蝕劑施加至基板W之塗佈裝置108、烘烤裝置110、用於將曝光圖案顯影成實體抗蝕劑圖案之顯影裝置112、蝕刻站122、執行蝕刻後退火步驟之裝置124以及可能另外的處理裝置126等等。度量衡裝置經組態以在顯影(112)之後或在進一步處理(例如,蝕刻)之後檢測基板。微影製造單元內之各種裝置受到監督控制系統SCS控制,監督控制系統SCS經由微影裝置控制單元LACU而控制微影裝置。該SCS允許操作不同裝置,從而得到最大產出率及產品良率。重要的控制機制為度量衡裝置140對各種裝置(經由SCS)、尤其對微影裝置100之回饋146。基於度量衡回饋之特性,判定校正性動作以改良後續基板之處理品質。 習知地藉由諸如描述於例如US2012008127A1中之進階程序控制(APC)之方法而控制及校正微影裝置之執行。進階程序控制技術使用施加至基板之度量衡目標之量測。製造執行系統(MES)排程APC量測且將量測結果傳達至資料處理單元。資料處理單元將量測資料之特性轉化為包含用於微影裝置之指令之配方。此方法對於抑制與微影裝置相關聯的漂移現象極有效。 藉由處理裝置執行之度量衡資料至校正性動作之處理對於半導體製造至關重要。除了度量衡資料以外,亦可需要個別圖案化器件、基板、處理裝置之特性及其他背景資料以進一步使製造程序最佳化。其中可用度量衡及背景資料整體上用於使微影程序最佳化之框架通常被稱作整體微影之部分。舉例而言,與倍縮光罩上之CD誤差相關之背景資料可用於控制各種裝置(微影裝置、蝕刻站)使得該等CD誤差將並不影響製造程序之良率。後續度量衡資料可接著用於驗證控制策略之有效性且可進一步判定校正性動作。 度量衡結果之使用對於微影程序之執行起重要作用。同時,隨著微影程序之每一收縮,對度量衡資料之相關性之要求不斷增加。 用於判定待藉由微影裝置施加之校正之度量衡結果的實例為用於更新微影裝置之最佳曝光設置的CD誤差量測。校正性動作為對橫跨場或基板(晶圓)之曝光劑量的調適。在許多狀況下,調適藉由局域地控制沿著曝光場之X軸之曝光劑量指紋(亦即依據x位置變化)來達成。在其他狀況下,沿著曝光場之Y軸(例如垂直於X軸)控制曝光劑量指紋(亦即依據y位置變化)。接著相對於與基板上之曝光場佈局相關聯的XY座標系統來界定表達曝光劑量調適所用之空間座標。在數學術語中,曝光劑量調適ED可寫成依據X變化之指紋調適F與依據Y變化之指紋調適G的疊加: ED(X,Y)=F(X)+G(Y) 在給定主要配備有在一個維度中限於校正參數(曝光劑量)之校正性裝置之微影裝置的架構之情況下,校正/控制沿著除了平行於X或Y軸以外之方向之曝光劑量的方式較不明顯。應瞭解,例如,包括項之調適函數無法藉由F(X)與G(Y)之疊加來達成,所述項包括乘積XY。 在基板之曝光之後,顯影該基板且特徵形成於抗蝕劑層中。特徵之特性係藉由度量衡工具予以量測,且取決於經量測特徵特性與所需特性之間的偏差,需要額外校正性動作。因為在顯影之後量測特徵,因此術語「顯影後檢測」(ADI)常常用以指在基板之抗蝕劑顯影之後執行的量測。 在基板之顯影之後,執行數個程序步驟以便將抗蝕劑中之特徵之佈局轉換為功能半導體組件之佈局。類似於微影裝置,其他處理裝置亦可配備有用以局域地控制待形成特徵(組件)之特性的構件。重要實例為在蝕刻站之基板固持器內存在多個熱區(參見圖2b)。根據藉由微影裝置執行之曝光,熱區之佈局通常與場佈局對準。藉由對基板之溫度之局域控制,會達成對基板上之蝕刻特性之局域控制。以此方式,可控制經蝕刻特徵屬性(CD)之某一空間指紋。如同微影裝置之控制,蝕刻特性EC之調適可表達為在X方向受控制之指紋H與在Y方向上受控制之指紋J的疊加:EA(X,Y)=H(X)+J(Y)。在給定配備有每尺寸受限於校正參數(CD)之校正性裝置之蝕刻裝置的架構之情況下,校正及/或控制沿著除了平行於X或Y軸以外之方向之蝕刻特性(影響CD)的方式較不明顯。 亦在蝕刻程序步驟之後,使用度量衡工具來量測經蝕刻特徵之特性。因為度量衡結果係關於經蝕刻特徵,因此術語「蝕刻後檢測」(AEI)常常用以指在對基板執行之蝕刻程序步驟之後執行的量測。 當考慮基於度量衡結果需要施加哪些校正性動作時,可考慮微影裝置及蝕刻站之校正能力。在許多狀況下,AEI結果最代表功能組件之效能,且因此考慮此等結果以便界定實施哪些校正性動作。微影裝置及處理(蝕刻)裝置兩者之校正性動作潛在地適用於改良經蝕刻特徵之特性。挑戰為將第一校正性動作指派給微影裝置且將額外的第二校正性動作指派給另一處理裝置。用以將校正性動作最佳地指派給裝置之方法常常被稱作「共同最佳化」;選擇基於與所考慮裝置相關聯的具體校正特性給出總的最佳結果之校正策略。 實施成功的共同最佳化策略所必要的為瞭解微影裝置及另一處理(蝕刻)裝置兩者之校正性動作之空間特性。在此內容背景中,引入術語「校正柵格」。校正柵格界定可校正參數變化(例如CD變化或曝光劑量變化)所沿著之主要軸線。通常對於微影裝置而言,校正柵格經對準至曝光場頂點。當微影裝置及蝕刻站兩者具有類似校正柵格(例如,對特徵特性之局域控制實質上限制在X及Y方向)時,共同最佳化在兩個裝置均具有互補校正柵格(例如並不具有相同柵格佈局)時很可能具有較小附加值。 說明性實例為曝光場內之沿著Y=X方向(X軸與Y軸成45度)之CD變化的校正。當微影裝置及蝕刻站兩者僅能夠校正沿著X或Y方向之CD變化時,微影裝置及蝕刻站校正性元件之共同最佳化將不會實質上改良所提及CD變化之校正。為了校正此CD變化,需要支援沿著Y=X方向之指紋調適。與先前所論述實例(ED(X,Y)及EA(X,Y))相比,此校正可不再分解為X相關貢獻與Y相關貢獻之總和,且因此微影裝置或其他處理裝置之校正性元件需要能夠獨立於沿著Y方向之指紋調適而調適沿著X方向之指紋。然而,此二維校正性元件將變得較複雜,此係因為其將需要利用大量可獨立地控制之像素元件。 為避免利用極複雜的校正性器件(在微影裝置或另一處理裝置內),提議維持使用簡單的一維校正性器件,但可使在例如微影裝置與蝕刻裝置之間施加校正所沿著之軸線的定向變化。藉此,相比於在兩個裝置均具有校正性元件之相同佈局的情況下,可在較大程度上支援對不與場佈局之X及Y軸對準的指紋之校正。假定微影裝置具有固定校正柵格,需要選擇具有不與曝光場對準之頂點之與處理裝置相關聯的校正柵格佈局。處理裝置(在大多數狀況下為蝕刻站)之校正柵格係由橫跨基板固持器或最緊密接近基板(例如影響蝕刻特性之電壓調節器件)之校正性元件(如加熱元件)的佈局界定。 作為所提議概念之一實例,圖2中展示曝光場(微影裝置)之佈局及蝕刻裝置之熱區。圖2a展示橫跨基板之曝光場D1至D2n之典型矩形柵格。曝光場D1至Dn之柵格與軸線X及Y對準。圖2b展示本發明之第一實施例。圖2b說明熱區之配置;區Z1至Zn分佈在相對於與微影裝置相關聯的校正柵格旋轉之柵格上。區Z1至Zn安置在經對準至軸線X'及Y'之柵格上,軸線X'及Y'被定向為與軸線X及Y成角度θ。此可藉由使實際熱區相對於基板(固持器)旋轉來達成。校正柵格之定向可參考其軸線而界定,該軸線在本文中被稱作校正軸線。 在本發明之第二實施例中,校正柵格之旋轉係藉由運用某一旋轉將基板裝載至蝕刻站之基板固持器來達成。此可藉由在將晶圓置放在基板固持器上之前使晶圓在執行器元件上旋轉來達成。可提供標準對準構件以(基於曝光場之凹口或佈局之位置)量測基板相對於校正性元件之旋轉角度。應注意,在將基板裝載至程序器件中時之基板之對準無需與在將其裝載至微影裝置中時之對準一樣準確。在許多狀況下,高達1度或2度或甚至5度之角度容限可為可接受的。此實施例之優點為可靈活地選擇處理裝置之校正柵格與同基板上之場佈局相關聯的柵格之間的角度θ。角度θ可選自45 +/- 45度之範圍。45度之角度將使得能夠校正沿著橫跨曝光場及/或基板之對角線之特徵特性(相對於與微影裝置相關聯的標稱場佈局)。 圖2c展示本發明之第三實施例。代替基於笛卡爾之柵格佈局,極柵格佈局界定與處理裝置相關聯的校正性元件(熱區)之配置。 圖3中描繪根據本發明之實施例之方法。基板在曝光104處藉由微影裝置曝光於器件圖案。經曝光基板經輸送且裝載200至處理工具122中以使曝光步驟中形成之圖案轉印至基板中。在輸送或裝載期間或當基板在處理工具122中時,基板經定向使得基板上之場之柵格與處理工具之校正性元件之柵格之間的角度為θ。 在本發明之第四實施例中,採用曲線校正柵格佈局。在第五實施例中,採用直線柵格佈局。 除了校正柵格之間的旋轉以外,亦可選擇其他操作以相對於第二裝置之校正柵格變更用於第一裝置之校正柵格。在第六實施例中,鏡射操作應用於第一校正柵格以界定第二校正柵格。 雖然上文已描述本發明之特定實施例,但應瞭解,可以與所描述之方式不同的其他方式來實踐本發明。 一實施例可包括含有機器可讀指令之一或多個序列之電腦程式,該等機器可讀指令經組態以指示如圖1中所描繪之各種裝置執行量測及最佳化步驟且控制如上文所描述之後續曝光程序。舉例而言,可在圖1之控制單元LACU或監督控制系統SCS或兩者之組合內執行此電腦程式。亦可提供資料儲存媒體(例如,半導體記憶體、磁碟或光碟),其中儲存有此電腦程式。 儘管上文可特定地參考在光學微影之內容背景中對本發明之實施例之使用,但應瞭解,本發明可用於其他應用中,例如壓印微影,且在內容背景允許的情況下不限於光學微影。在壓印微影中,圖案化器件中之構形(topography)界定基板上產生之圖案。可將圖案化器件之構形壓入至被供應至基板之抗蝕劑層中,在基板上,抗蝕劑係藉由施加電磁輻射、熱、壓力或其組合而固化。在抗蝕劑固化之後,將圖案化器件移出抗蝕劑,從而在其中留下圖案。 本文中所使用之術語「輻射」及「光束」涵蓋所有類型之電磁輻射,包括紫外線(UV)輻射(例如,具有為或約為365奈米、355奈米、248奈米、193奈米、157奈米或126奈米)及極紫外線(EUV)輻射(例如具有在1奈米至100奈米範圍內之波長),以及粒子束,諸如離子束或電子束。可使用合適源在UV及EUV波長內進行散射計及其他檢測裝置之實施,且本發明決不限於使用IR及可見光輻射之系統。 術語「透鏡」在內容背景允許的情況下可指各種類型之光學組件中之任一者或其組合,包括折射、反射、磁性、電磁及靜電光學組件。反射組件很可能用於在UV及/或EUV範圍內操作之裝置中。 以下為本發明之例示性實施例: A)一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件經配置成沿著具有除了平行於與該基板上之場之一佈局相關聯之一柵格的X軸或Y軸以外之一方向之至少一個軸線。 B)如實施例A)之基板處理裝置,其中該軸線經定向在平行於該基板或該基板處理裝置之一基板固持器表面之一平面內。 C)如實施例A)或B)之基板處理裝置,其中該軸線經配置為相對於與該基板上之場之該佈局相關聯的該柵格之X軸或Y軸成45 +/- 40度之一角度。 D)如前述實施例中任一項之基板處理裝置,其進一步包含用以相對於配置該等校正性元件所沿著之該軸線旋轉該基板之構件。 E)如實施例D)之基板處理裝置,其中該等構件允許選擇在0度與90度之間的旋轉角度。 F)一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據一極柵格佈局進行配置。 G)一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據一曲線或一直線柵格佈局進行配置。 H)一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據由對與該基板上之場之一佈局相關聯的一柵格執行之一鏡像操作引起的一柵格佈局進行配置。 I)一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據由對與該基板上之場之一佈局相關聯的一柵格執行之一按比例調整操作引起的一柵格佈局進行配置。 J)一種用以最佳化一半導體程序之方法,該方法包含使用如實施例A)至I)中任一項之基板處理裝置之一步驟。 本發明之廣度及範疇不應由上文所描述之例示性實施例中之任一者限制,而應僅根據以下申請專利範圍及其等效者進行界定。
100‧‧‧微影裝置
104‧‧‧曝光
108‧‧‧塗佈裝置
110‧‧‧烘烤裝置
112‧‧‧顯影裝置
122‧‧‧蝕刻站/處理工具
124‧‧‧執行蝕刻後退火步驟之裝置
126‧‧‧處理裝置
140‧‧‧度量衡裝置
146‧‧‧回饋
200‧‧‧裝載
D1‧‧‧曝光場
D2‧‧‧曝光場
D3‧‧‧曝光場
D4‧‧‧曝光場
D5‧‧‧曝光場
D6‧‧‧曝光場
D7‧‧‧曝光場
D8‧‧‧曝光場
D9‧‧‧曝光場
D10‧‧‧曝光場
D11‧‧‧曝光場
D12‧‧‧曝光場
Dn‧‧‧曝光場
LACU‧‧‧微影裝置控制單元
SCS‧‧‧監督控制系統
W‧‧‧基板
X‧‧‧方向/軸線
X'‧‧‧軸線
Y‧‧‧方向/軸線
Y'‧‧‧軸線
Z1‧‧‧區
Z2‧‧‧區
Z3‧‧‧區
Z4‧‧‧區
Z5‧‧‧區
Z6‧‧‧區
Z7‧‧‧區
Z8‧‧‧區
Z9‧‧‧區
Z10‧‧‧區
Z11‧‧‧區
Z12‧‧‧區
Zn‧‧‧區
θ‧‧‧角度
現將作為實例參考隨附圖式描述本發明之實施例,在該等隨附圖式中: 圖1描繪在一起形成用於半導體器件之生產設施之微影裝置以及其他裝置; 圖2A描繪具有呈矩形陣列之目標部分之基板; 圖2B描繪相對於處理工具之區的柵格定向之基板; 圖2C描繪程序器件之邊緣區之配置;且 圖3描繪根據本發明之實施例之器件製造程序。
Claims (10)
- 一種基板處理裝置,其包含: 一基板裝載器件,其經組態以在相對於與一基板上之場之一佈局相關聯的一柵格之一預定定向上裝載該基板; 校正性元件,其等經組態以使得能夠局域校正對一基板執行之一程序之一特性;其特徵在於 該等校正性元件經配置成沿著具有除了平行於該柵格之X軸或Y軸以外之一方向之至少一個校正軸線。
- 如請求項1之基板處理裝置,其中該校正軸線經定向在平行於該基板或該基板處理裝置之一基板固持器表面之一平面內。
- 如請求項1或2之基板處理裝置,其中該校正軸線經配置為相對於與該基板上之場之該佈局相關聯的該柵格之X軸或Y軸成45 +/- 40度之一角度。
- 如請求項1或2之基板處理裝置,其進一步包含經組態以相對於該校正軸線旋轉該基板之旋轉構件。
- 如請求項4之基板處理裝置,其中該等旋轉構件允許選擇在0度與90度之間的旋轉角度。
- 一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據一極柵格佈局進行配置。
- 一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據一曲線或一直線柵格佈局進行配置。
- 一種基板處理裝置,其包含經組態以使得能夠局域校正對一基板執行之一程序之一特性的校正性元件,該基板處理裝置之特徵在於該等校正性元件根據由對與該基板上之場之一佈局相關聯的一柵格執行之一鏡像操作引起的一柵格佈局進行配置。
- 一種用以最佳化一半導體程序之方法,該方法包含使用如請求項1之基板處理裝置之一步驟。
- 一種器件製造程序,其包含: 使用一微影裝置將一圖案曝光至一基板上之場之一柵格上; 使用校正性元件之一柵格將該基板輸送至一處理工具; 定向該基板使得場之該柵格相對於校正性元件之該柵格成一預定角度;及 使用該處理工具將該圖案轉印至該基板中。
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