200411759 玖、發明說明： 【發明所屬之技術領域】 本發明一般係關於一種利用腐蝕性蝕刻劑來蝕刻矽晶圓 的方法。本發明進一步關於一種蝕刻矽晶圓的方法，用以 製造具有改良表面特徵（例如平坦度及微細表面形狀）的矽 晶圓。 【先前技術】 通常可利用下面的多重步驟方法來獲得矽晶圓：於垂直 一單晶砍塊的軸線的方向中將該矽塊切成薄片，用以產生 薄晶圓，削切或描刻出該等晶圓的邊緣；研磨或碾磨該等 晶圓，用以移除因切片方法所導致的表面損壞；以化學方 式來蝕刻該等晶圓，用以移除前面的複數個整形步驟所產 生的機械損壞；以及最後，以化學方式/機械方式來對該邊 緣進行拋光處理，而且每個晶圓的至少其中一面皆具有膠 狀的碎土泥及化學㈣劑’用以確保該等晶圓具有非常平 坦的、可反光的且沒有損壞的表面。而後通常可清洗該等 晶圓，並且於包裝之前進行品質檢查。 ，矽晶圓通常會呈現出表面缺陷及/ 在進行化學蝕刻之前 或次表面缺陷（埋植顆粒），以及物理損壞（例如因碌磨、研 磨及邊緣描刻等方法而對該晶圓所造成的微裂痕、裂缝或 應力）。該些缺陷通常會發生在該晶圓 方至少約2·5 μπχ以上的區域中。因此， 表面至該晶圓表面下 為移除該些缺陷，通 常必須利用酸性及/或腐蚀性化學蚀刻劑從該晶圓表面中 移除至少約2.5㈣的矽，以便移除該等埋植顆粒、污染物、 88173 200411759 以及該被移除之矽層中内含的物理損壞。 酸性及腐蝕性化學蝕刻劑都可用以蝕刻矽晶圓的表面。 其中一種最常見的酸性蝕刻劑化學式包含下面所組成的水 溶液：氫氟酸（HF)、确酸（HN〇3)、以及水。腐蚀性姑刻劑 通常包含一種以上的鹼金屬氫氧化物，例如氫氧化鉀（KOH) 或氫氧化鈉（NaOH)、以及水。 相較於以腐蝕性蝕刻劑來蝕刻的晶圓，於部份實例中， 酸性蝕刻劑為較佳的選擇，因為其通常可製造出平滑的晶 圓表面，-表面粗糙度較低。不過，酸性蝕刻劑卻很容易於 該晶圓被蝕刻的表面上產生不必要的氣相與固相化學物 質，形成污點，阻礙進一步的反應該瞭解的係，並且會產 生不一致的蚀刻結果（參看由D.G. Schimmel等人所著，L Electrochem. Soc.於 1978年出版的「An Examination of the Chemical Staining of Silicon」，第 125冊、第 152至 155 頁）。 該等含有硝酸的酸性蝕刻劑會於該蝕刻方法期間進行反 應，產生含有氮的氧化物的有毒氣體，因為該些氣體會對 人體造成毒害，所以必須進行安全控制，並且必須採用特 殊的處理程序，避免污染環境，並且可符合環境管理規定。 另外，為能夠利用酸性蝕刻劑取得非常平滑的表面，必須 從該等矽晶圓中移除大量的矽，通常必須從該晶圓的前後 表面移除約10至15 μπι。一般來說，最好能夠限制從該等晶 圓表面中被移除的碎的數量，如此方能限制晶圓厚度的變 化。 酸性蝕刻劑通常可以極高的蝕刻速率來蝕刻該晶圓，而 88173 200411759 且主要係以該等反應物至該晶圓表面的質量轉移來控制該 蝕刻速率。在質量轉移型蝕刻方法期間，因為很難精確地 控制矽的移除過程，所以一經過酸蝕刻的晶圓的平坦度便 會受到下滑。同時，快速的質量轉移型酸蝕刻方法碰上氣 泡遮蓋（也就是，附著於部份晶圓表面上的氣態蚀刻反應副 產物，例如氫氣、NOx)時，便很容易於該被蝕刻晶圓之微 細表面形狀中造成明顯的變化。（參看由Kulkarni等人所 著，J· Electrochem· Soc·於 2000年出版的「Acid-Based Etching of Silicon Wafers: Mass-Transfer and Kinetic Effects」，第 147 (1)冊、第176至188頁） 腐蝕性蝕刻劑有數項優點優於酸性蝕刻劑。舉例來說， 相較於以酸性姓刻劑來姓刻的晶圓，腐姓性触刻劑比較容 易製造出表面較平坦的晶圓，同時僅需使用非常簡單的蝕 刻設備。一般來說，腐蚀性蚀刻劑的蚀刻速率比酸性姓刻 劑還慢，而且主要係以反應動力學來控制該蝕刻方法，而 非以該等反應物至該晶圓表面的質量轉移來控制。吾人希 望能夠於化學蝕刻期間來限制從該表面中被移除的矽的數 量，如此方能限制晶圓厚度或平坦度的變化。當從該等晶 圓表面中被移除的矽的數量提高時，通用背面參照指示範 圍（GBIR)(該晶圓最大厚度與最小厚度之間的差異）通常亦 會隨著增加。腐蝕性蝕刻劑通常可產生低GBIR (例如約+0.1 μπι)的晶圓，而酸性蚀刻劑則通常會產生高GBIR (例如約介 於+0·5至+1·5 μιη之間）的晶圓。相較於經過酸蚀刻的晶圓來 說，就此方面而言，最好能夠使用腐蝕性蚀刻溶液，因為 88173 200411759 於後續處理期間僅必須從該等晶圓表面中移除非常少的碎 便可達到令人滿意的GBIR。再者，因為腐姓性蚀刻劑的钱 刻速率較低，所以亦比較容易降低被附著在該晶圓表面之 上含有氣泡的氣態副產物的密度。出現在該晶圓表面上的 氣泡數量下降便可降低該晶圓微細表面形狀上的「氣泡遮 蓋」效應。所以，即使會於該晶圓表面上形成氣泡，因為 可以反應動力學來控制該方法，所以經過腐蝕性蝕刻的晶 圓的微細表面形狀通常會比經過酸蝕刻的晶圓更為一致。 除了提供具有改良表面特徵（例如平坦度及微細表面形 狀）的蚀刻晶圓，基本上，腐姓性姓刻方法比較安全，並且 可以比酸性蝕刻方法還低廉的成本來進行作業。因腐蝕性 蝕刻方法而產生的任何氣態副產物的數量通常非常的低， 因此可以安全且簡單的方式來對其進行處置。舉例來說， 任何生成的氫氣的數量通常會低於其爆發下限，因而可進 行安全且簡單的處置。腐蝕性蝕刻劑與表面組織反應的速 度會比酸性蝕刻劑與表面組織反應的速度還慢，因此相較 於酸性蝕刻劑，當意外暴露於腐蝕性蝕刻劑中時，對操作 人員所造成的危險性會比較低。 不過，腐蚀性蝕刻劑並非每方面都優於酸性蝕刻劑。如 前面所述，經過酸蝕刻的晶圓的表面粗糙度會低於經過腐 蝕性蝕刻的晶圓。一般來說，酸性蝕刻方法所製造出來的 晶圓的平均表面粗糙度（Ra)約介於〇·〇9 μιη至0.16 μηι，而腐 蝕性蚀刻方法所製造出來的晶圓的平均表面粗糙度約介於 0.27 μπι至0.35 μιη Ra。經過腐蚀性蚀刻的晶圓的粗链度比 88173 -10- 200411759 較大的原因係因為大部份都係沿著可產生「魚鱗」外觀特 徵之小晶面的結晶面來優先進行蝕刻。 利用後續的拋光處理便可克服因慣用腐蝕性蝕刻劑所導 致的高表面粗縫度及小晶面，但是用以對該晶圓之前表面 及邊緣表面進行抛光處理所需要的時間會因表面粗糙度提 同而大幅增加。因此，相較於經過酸性蝕刻的晶圓，經過 腐#性敍刻的晶圓中的高表面粗糙度及小晶面則會降低產 1且向正植製造方法的成本。此外，有時候表面粗縫度 過大’使-得裝置製造廠（其可規定該晶圓「被蝕刻」的背面） 無法接雙經過腐蝕性蝕刻的晶圓，因為在使用該晶圓之前 他們還必須對該背面作進一步的處理。 因此’向來都一直需要一種能夠製造晶圓的腐蝕性蝕刻 方法’使得該等晶圓經過處理便可輕易地表現出預期的標 準表面特徵。 【發明内容】 所以，本發明的各項目的係：提供一種改良的腐蝕性蝕 刻劑，用以從矽晶圓表面中移除矽；提供一種利用腐蝕性 蝕刻劑來蝕刻矽晶圓的方法，使其相較於利用酸性蝕刻劑 來蝕刻的晶圓可產生具有改良的平坦度及微細表面形狀的 蚀刻晶圓；提供一種利用腐姓性触刻劑來餘刻碎晶圓的方 法，使其相較於利用慣用的腐蝕性蝕刻劑來蝕刻的晶圓可 產生具有改良的表面特徵的蚀刻晶圓；提供一種利用腐蝕 性蚀刻劑來蝕刻矽晶圓的方法，使其相較於利用慣用的腐 蝕性蝕刻劑來蝕刻的晶圓可產生具有較小表面粗糙度的蝕 88173 -11 - 200411759 刻晶圓；提供一種碎晶圓的腐#性姓刻劑方法，其可改良 後續拋光步驟的產量；提供一種蝕刻矽晶圓的方法，相較 於利用酸性蝕刻劑來蝕刻矽晶圓的方法，其具有強化的安 全性特徵；以及提供一種腐蝕性蝕刻劑及一種蝕刻碎晶圓 的方法，其可降低毒物散出的數量及/或降低環境控制的成 本。 所以’簡單地說’本發明係關於用以從一硬晶圓表面中 移除矽的蚀刻方法，其包括以一種水溶液型態的腐蝕性蝕 刻劑來痰觸該矽晶圓表面，該水溶液包含水以及氫氧化物 離子源。該腐蝕性蝕刻劑中的水的重量百分比濃度低於 45% 〇 於另一具體實施例中，接觸到該矽晶圓表面的腐蝕性蝕 刻劑中的氫氧化物離子源的重量百分比濃度高於55%。 於另一具體實施例中，接觸到該矽晶圓表面的腐蝕性蝕 刻劑中的氫氧化物離子源的濃度至少約為該腐蝕性蝕刻劑 中的氫氧化物離子源的飽和濃度的70%。 於另一具體實施例中，用以從一矽晶圓表面中移除矽的 蝕刻方法包括以一種水溶液型態的腐蝕性蝕刻劑來接觸該 矽晶圓表面，該水溶液包含水、氫氧化物離子、以及不會 於該腐敍性姓刻劑中分解或發生反應的鹽類添加劑。該鹽 類添加劑包括由下面所組成之群中所選出的化合物：無機 鹼金屬鹽類、鹼土金屬鹽類、以及其混合物；而且該腐蝕 性蝕刻劑中的鹽類添加劑的莫耳百分比濃度至少约為4%。 於另-具體實施例中，用以從-妙晶圓表面中移除碎的 88173 -12 - 200411759 ㈣方法包括以-種水溶液型態的腐錄蚀刻劑來接觸該 碎晶圓表面，該水溶液包含水、氫氧化物離子、以及鹽類 添加劑，該鹽類添加劑包括由下面所組成之群中所選出的 化合物：碳酸鉀以及氟化鉀。該腐蝕性蝕刻劑中的鹽類添 加劑的莫耳百分比濃度至少約為1〇/〇。 本發明進一步關於一種用以蝕刻矽晶圓的腐蝕性蝕刻 劑，其包括-水溶液，該水溶液包含水、氫氧化物離子、 以及不會於該腐蝕性蝕刻劑中分解或發生反應的鹽類添加 劑。該氬類添加劑包括由下面所組成之群中所選出的化合 物：無機鹼金屬鹽類、鹼土金屬鹽類、以及其混合物，而 且該腐蝕性蝕刻劑中的鹽類添加劑的莫耳百分比濃度至少 約為4%。 於另一具體實施例中，用以蝕刻一矽晶圓的腐蝕性蝕刻 劑包括一水溶液，該水溶液包含水、氫氧化物離子、以及 鹽類添加劑，該鹽類添加劑包括由下面所組成之群中所選 出的化合物：碳酸鉀以及氟化鉀。該腐蝕性蝕刻劑中的鹽 類添加劑的莫耳百分比濃度至少約為1〇/〇。 本發明進一步關於一種單晶矽晶圓，其包括一中央軸、 通常垂直於該中央軸的前後表面、一周圍邊緣、以及一半 徑R(其係從該中央軸延伸至該晶圓的周圍邊緣）。經過拋光 後’該單晶碎晶圓的前表面部位平坦度平均值小於約〇 13 μπι，前表面部位平坦度最大值小於約〇 18 μπι，前表面2mm X 2 mm微細表面形狀小於約20 nm，前表面10 mm X 1〇 mm微 細表面形狀小於約40 nm。 88173 • 13 - 200411759 於後文中將可明白且會提出本發明的其它目的及特點。 【實施方式】 已經有人發現到可製造具有改良的表面特徵之矽晶圓的 腐蝕性蝕刻方法。本發明的方法提供腐蝕性蝕刻中公認的 優點，其可克服或最小化慣用的腐蝕性蝕刻與酸性蝕刻中 公認的限制。相較於利用慣用的腐蝕性蝕刻劑所蝕刻出來 的晶圓，本發明所蝕刻出來的晶圓會呈現出較少的表面粗 糙度；而且相較於以酸性蝕刻所蝕刻出來的晶圓，本發明 所蝕刻出-來的晶圓於經過拋光之後還會呈現出較高的平坦 度及較低的微細表面形狀變化。相較於以慣用的腐姓性蝕 刻劑所蝕刻出來的晶圓，本發明所蝕刻出來的晶圓還會進 一步地呈現出較高的平坦度及較低的微細表面形狀變化。 本發明所使用的腐蝕性蝕刻劑係一種水溶液的型態，其包 含水以及氫氧化物離子源。於其中一具體實施例，該腐蝕 性蝕刻劑的一般特徵為水的濃度低於先前所使用的濃度。 於另一具體貫施例，該腐蝕性蝕刻劑的額外或替代特徵為 该等氫氧化物離子源的濃度高於先前所使用的濃度◊於另 一具體貫施例’該腐蝕性蝕刻劑包括鹽類添加劑。 本發明的方法採用矽晶圓作為原料，該矽晶圓係從單晶 的碎塊中被切割下來且經過進一步的處理，例如利用慣用 的研磨設備來描刻或削切出該晶圓的周圍邊緣。此種處理 可於進一步的處理期間降低晶圓的損壞風險，降低因切割 過程所導致的不均句損壞，並且粗略地改良前後表面的一 般平坦度及平行度。可以利用熟習本技術的人士已知的任 88173 •14· 200411759 何方法從該矽塊中切割出該晶圓，舉例來說，内徑切割設 備及微鋸切割設備。研磨法便是熟習本技術的人士所熟知 的方法。典型的研磨法通常可利用樹脂黏著劑、以約2000 RPM至約4000 RPM來作業的1200至6000個嚙合齒的研磨輪 用以從該晶圓的每個表面中移除約20 μιη至約30 μπι的材 料，以便粗略地改良平坦度。 除了研磨法之外，還可利用下面的碾磨機來碾磨該等晶 圓：Peter Wolters AG (位於德國蘭斯堡）所製造的AC 1200、 AC 1400 : AC 1500周轉式碾磨機；或是SpeedFamKK (位於 日本）或Fujikoshi (位於日本）所製造的碾磨機。合宜的碾磨 砂壤微細表面形狀Al2〇3研磨料，例如由Fujimi America, Inc. (Wilsonville，OR)所製造的 F0_1200、PWA 9、或PWA 11M。 如果除了研磨之外還要碾磨該等晶圓的話，那麼該些機械 整形方法的順序並不重要。 該矽晶圓可針對預期的半導體應用而具有任何的導體 性、電阻率、直徑及目標厚度。舉例來說，直徑一般至少 約為100 mm，通常為150 mm、200 mm、300 mm以上，而厚 度則介於約475 μιη至約900 μπι以上之間，而且厚度通常會 隨著直徑的增加而增加。該晶圓還可能具有任何的結晶配 向。不過，一般來說，該等晶圓都具有<1〇〇>及<111>結晶 配向。 從該矽塊中切割下來且經過上述該等機械整形處理之 後，該晶圓通常會呈現出表面及/或次表面缺陷（例如埋植顆 粒），以及物理損壞（例如微裂痕、裂缝或應力）。該些缺陷 88173 -15- 200411759 通常會發生在該晶圓表面至該晶圓表面下方至少約2.5 μ m 以上的區域中。此外，該晶圓表面的平均表面粗链度通常 介於至少約50 nm至約200 nm Ra以上之間。利用能夠測量 表面粗糙度的任何度量裝置便可測量出表面粗糙度。熟習 本技術的人士都知道此等裝置。舉例來說，可以利用 Chapman Instruments (Rochester，美國紐約州）所售的 MP 3000表面測量裝置來測量表面粗糙度，或是利用下面其它 的度量裝置來測量，例如：AFM顯微鏡、50X放大倍率的 Nomarski顯微鏡、10X放大倍率的Wyko-2D顯微鏡、光學干 涉計、或是由前Federal Products, Inc.(現在稱為 Mahr Federal， Inc. (Providence，美國羅德島州））所製造的 Federal Products Surface Analyzer 5000 〇 接著，便可對該等經過整形的晶圓進行化學蝕刻，以便 實質減少該些機械缺陷。根據本發明，可以使用一種水溶 液型態的腐蚀性蚀刻劑，其包含水以及氫氧化物離子源。 如下面的詳細說明，該腐蝕性蝕刻劑可能進一步包括鹽類 添加劑。雖然本發明的姓刻方法可能僅使用本文所述之腐 蝕性蝕刻劑來進行蝕刻，不過應該瞭解的係，本文所揭示 的腐蝕性蝕刻劑亦可應用於同時採用酸性蝕刻劑及/或其 它腐蝕性蝕刻劑之多重步驟的蝕刻準則中。 根據本發明其中一項具體實施例，該腐蝕性蝕刻劑水溶 液中的水的濃度低於慣用的腐蝕性蝕刻劑的濃度。更明確 地說，該腐蝕性蝕刻劑中的水的重量百分比濃度低於45%。 最新的實驗證明，相較於以慣用的腐蝕性蝕刻劑所蝕刻的 88173 -16 - 200411759 晶圓’以本發明之腐蝕性蝕刻劑所蝕刻出來的晶圓具有較 少的表面粗糙度；而且相較於以酸性蝕刻劑及慣用的腐蝕 性蚀刻劑所蝕刻出來的晶圓，以本發明之腐蝕性蝕刻劑所 蚀刻出來的晶圓還具有改良的平坦度及微細表面形狀。吾 人相信該等改良的表面特徵至少部份係因為當該腐蝕性蝕 刻劑中的水的重量百分比濃度低於45%時提高了該腐蝕性 姓刻劑的表面張力的關係。表面張力提高便會減低於該實 施過程期間出現在該晶圓表面上的氣泡的平均尺寸。因為 吾人相信·小晶面的尺寸至少部份係由該晶圓表面上的氣泡 尺寸來決定，縮小該晶圓表面上的氣泡尺寸便可較小的氣 /包遮盍’並且對該晶圓表面進行更均勻的蝕刻。吾人相信 對该晶圓表面進行更均勻的蝕刻至少部份也是因為當該蝕 二>1 d的表面張力提局時該等小型氣泡與所看見的晶圓表面 的接觸角度較小的關係。較小的接觸角度可降低直接接觸 到每個個別氣泡的晶圓表面大小，用以提供更均勻的蝕刻 晶圓表面。 吾人進一步相信，該等蝕刻晶圓之改良的表面特徵係部 6因為當該腐蝕性蝕刻劑中的水的濃度降低時會減緩該蝕 刻過程期間的氧化速率的關係。可以利用兩步驟的方法來 進行矽蝕刻··利用該蝕刻劑中的水來進行矽氧化，並且利 用該蝕刻劑中的氫氧化物離子源中的鹼金屬成份來溶解該 二氧化矽。因此，降低水濃度將會減緩氧化速率，從而減 緩蝕刻速率。 彳 更月確地說，造成總氧化速率減緩的改良的表面特徵可 88173 •17- 200411759 月匕係因為減少該晶圓之<1〇〇〉結晶面中的優先蝕刻所導致 的。明確地說，已經有人發現到可將<100>結晶面中的蝕刻 速率下降達40%。<100>結晶面中的蝕刻速率下降效應最為 明顯’因為該些平面中的蚀刻速率大於所有其它平面中的 蝕刻速率。因為<100>結晶面中的蝕刻速率及所有其它晶圓 表面中的敍刻速率之間的差異縮小，所以亦可減少與其相 關聯的小晶面現象及粗糙度。一般來說，<1〇〇>結晶面和所 有其它晶圓表面中的蝕刻速率比例約介於〇 7至5之間。根據 本發明，$100>結晶面和所有其它晶圓表面中的蝕刻速率比 例較佳的係接近1。 該腐蝕性蝕刻劑通常會包括重量百分比至少約10%的 水’甚至會包括重量百分比至少約20%的水，以及重量百分 比至少約25%的水。較佳的係，該腐蝕性蝕刻劑包括重量百 分比介於約25%至約45%之間的水；更佳的係，包括重量百 分比介於約30%至約42%之間的水；甚至包括重量百分比介 於約30%至約37%之間的水。 於特定的實例中，以莫耳百分比來定義該腐蝕性蝕刻劑 中的水的濃度可能比較實用。因此，該腐蝕性蝕刻劑中的 水的莫耳百分比濃度通常不超過約68%。一般來說，該腐蝕 性蝕刻劑中的水的莫耳百分比濃度通常不超過約65%;大部 份的莫耳百分比濃度都不超過約55%;甚至莫耳百分比濃度 都不超過約45%。較佳的係，該腐蝕性蝕刻劑中的水的莫耳 百分比濃度介於約5%至約45%之間；更佳的係介於約5%至 約20%之間。 88173 -18- 200411759 提高該腐姓性蝕刻劑中氫氧化物離子源的濃度便可達到 預期較低的水濃度。 根據本發明其中一具體實施例，該腐蝕性蚀刻劑中的氫 氧化物離子源的重量百分比濃度會大於55%。較佳的係，該 腐敍性姓刻劑中的氫氧化物離子源的重量百分比濃度至少 約為57% ;更佳的係重量百分比濃度至少約為58% ;更佳的 係重量百分比濃度至少約為6〇%;甚至更佳的係重量百分比 濃度至少約為62%。根據本發明其中一具體實施例，該腐蝕 性敍刻劑-中的氫氧化物離子源的重量百分比濃度至少約為 65。/。。通常，該腐蝕性蝕刻劑中的氫氧化物離子源的重量百 分比濃度不會超過约75%。因此，該腐蝕性蝕刻劑中的氫氧 化物離子源的重量百分比濃度通常係介於約58%至約7〇% 之間；較佳的係，重量百分比濃度介於約58%至約65%之 間；更佳的係，重量百分比濃度介於約62%至約65%之間。 合宜的氫氧化物離子源包括四甲基氫氧化銨以及鹼金屬的 氫氧化物（例如氫氧化鈉、氫氧化鉀、氫氧化铯、氫氧化鋰、 以及其混合物）。於較佳的具體實施例中，該氫氧化物離子 源包括氫氧化4甲；於另一較佳的具體實施例中則包括氫氧 化飾。 吾人已經發現，當使用氫氧化鈉作為氫氧化物離子源 時，藉由具有低濃度的水的腐蝕性蝕刻劑來縮小氣泡尺寸 及提高表面張力以便縮小小晶面尺寸及表面粗糖度的效應 會比較顯著。因此，於較佳的具體實施例中，該氫氧化物 離子源會包括氫氧化鈉。於一具體實施例中，該氫氧化物 88173 -19- 200411759 離子源包括氫氧化鈉，該腐蝕性蝕刻劑中的氫氧化鈉的重 量百分比濃度至少約為58%;更佳的係重量百分比濃度至少 約為61% ;甚至更佳的係重量百分比濃度至少約為62%。一 般來說’氫氧化鈉的重量百分比濃度不超過約68%。因此， 該腐#性姓刻劑中的氫氧化鈉的重量百分比濃度通常係介 於約58%至約68%之間；較佳的係，重量百分比濃度介於約 58〇/〇至約63%之間；更佳的係，重量百分比濃度介於約61〇/〇 至約63%之間。雖然氫氧化鈉係較佳的氫氧化物離子源，不 過應該瞭-解的係，使用重量百分比濃度超過55%的其它氫氧 化物離子源（例如氫氧化鉀y的腐蝕性蝕刻劑同樣可提供本 文所討論的有利結果。於其中一具體實施例，該氫氧化物 離子源包括氫氧化鉀，該腐蝕性蝕刻劑中的氫氧化鉀的重 量百分比濃度至少約為57%;更佳的係重量百分比濃度至少 約為60%。一般來說，氫氧化鉀的重量百分比濃度不超過約 63%。因此’該腐蝕性蝕刻劑中的氫氧化鉀的重量百分比濃 度通常係介於約57%至約63%之間；較佳的係，重量百分比 濃度介於約60%至約63%之間。 於特定的實例中（例如如同含有鹽類添加劑的腐蝕性蝕 刻劑的情況一般，當該腐餘性姓刻劑的成份具有各式各樣 的分子重量時），以莫耳百分比來定義該腐蝕性蝕刻劑中的 氫氧化物離子源的濃度可能比較實用。因此，該腐姓性蚀 刻劑中的氫氧化物離子源的莫耳百分比濃度通常不超過約 70%。一般來說，該腐蝕性蚀刻劑中的氫氧化物離予源的莫 耳百分比濃度通常不超過約68°/。；大部份的莫耳百分比濃度 88173 -20- 200411759 都不超過約55% ;甚至莫耳百分比濃度都不超過約45%。通 常’該腐蝕性蝕刻劑中的氫氧化物離子源的莫耳百分比濃 度通常係介於約30%至約45%之間。於該氫氧化物離子源包 括氫氧化鈉的腐蝕性蝕刻劑情況中，該腐蝕性蝕刻劑中的 氫氧化鋼的莫耳百分比濃度通常不超過約55%。一般來說， 於此具體實施例中，該腐蝕性蝕刻劑中的氫氧化鈉的莫耳 百分比濃度至少約為35%，大部份的莫耳百分比濃度則介於 約40%至約50%之間。進一步地根據此具體實施例，該腐蝕 性餘刻劑-中的水的莫耳百分比濃度通常都不超過68%。當該 氫氧化物離子源包括氫氧化鉀時，該腐蝕性蝕刻劑中的氫 氧化_的莫耳百分比濃度通常都不超過55%。一般來說，於 此具體實施例中，該腐蝕性蝕刻劑中的氫氧化鉀的莫耳百 分比濃度至少約為30%，大部份的莫耳百分比濃度則介於約 30%至約40%之間。進一步地根據此具體實施例，該腐蝕性 蚀刻劑中的水的莫耳百分比濃度通常都不超過。 根據本發明的較佳具體實施例，該腐蝕性蝕刻劑中的氫 氧化物離子源的濃度位於規定的蝕刻溫度處的飽和點處或 其附近。當該腐蝕性蝕刻劑的溫度上升時，該腐蝕性蝕刻 劑中的氫氧化物離子源的濃度通常會隨著提高。不過，應 孩瞭解的係，該腐蝕性蝕刻劑中的氫氧化物離子源的濃度 較佳的係不可提鬲至會形成不預期的沉澱物的濃度點。也 就是，製備該腐蝕性蝕刻劑（其包含水及氫氧化物離子源， 以及任何其它成份）時，較佳的係能夠讓該蚀刻劑於可溶合 斤有成伤的規定姓哥j溫度處包括均質的單液相混合物。較 88173 -21 - 200411759 佳的係此夠避免產生沉澱物，因為任何生成的沉派物都可 能會附著或形成於該晶圓表面之上，⑼而干擾到腦刻過 程，並且對該蝕刻晶圓的微細表面形狀造成負面影響。於 該腐蚀性餘刻劑中出現沉殿物還可能會導致作業問題，例 如堵塞製程設備、或是干擾到對該蝕刻劑進行溫度控制。 於本發明的其中一具體實施例中，可將該腐蚀性蝕刻劑 中的氫氧化物離子源的濃度定義為該腐蝕性蝕刻劑中的氫 氧化物離子源於規定蝕刻溫度處的至少約7〇%的飽和濃 度，更佳-的係至少約74%，甚至更佳的係至少約77%。不過， 為降低形成沉殿物的風險，該腐蚀性餘刻劑中的氫氧化物 離子源的濃度通常不會超過該腐蚀性餘刻劑中的氫氧化物 離子源的約95%的飽和濃度。因此，該腐蝕性蝕刻劑中的氫 氧化物離子源的濃度通常係介於該腐蝕性蝕刻劑中的氫氧 化物離子源於規定蝕刻溫度處的約7〇%至約95%的飽和濃 度之間。於較佳的具體實施例，該腐蝕性蝕刻劑中的氫氧 化物離子源的濃度通常係介於該腐蝕性蝕刻劑中的氫氧化 物離子源於規定蝕刻溫度處的約74%至約90%的飽和濃度 之間。於另一較佳的具體貫施例’該腐姓性敍刻劑中的氫 氧化物離子源的濃度通常係介於該腐蝕性蝕刻劑中的氫氧 化物離子源於規定蝕刻溫度處的約74%至約81%的飽和濃 度之間。 於本發明的實作中，該腐蝕性蝕刻劑的溫度通常會維持 在至少約70 °C的溫度，大部份會維持在至少約75 °C的溫 度’甚至會維持在至少約80t的溫度。於本發明的其中一 88173 -22- 200411759 具體實施例中，該腐蝕性蝕刻劑的溫度會維持在至少約9〇°C 的溫度；於另一具體實施例中則會維持在至少約1 00。〇的溫 度。該腐蝕性蝕刻劑的溫度通常會維持在約70°C至約120°C 之間，較佳的係維持在約70°C至約110°C之間，更佳的係維 持在約70°C至約l〇〇°C之間，更佳的係維持在約75°C至約90°C 之間，甚至維持在約75°C至約85t之間。當該腐蝕性蝕刻 劑含有鹽類添加劑時，可利用上述範圍中較高的溫度（例如 介於約100°C至約120°c之間）用以於該腐蝕性蝕刻劑來幫助 溶解該Μ類添加劑。不過，應該瞭解的係，不論該腐蝕性 蚀刻劑是否包括鹽類添加劑，上述的優先例一般都適用。 如上所述’本發明實作中所使用的腐姓性姓刻劑可能包 括鹽類添加劑，其有助於產生該蝕刻晶圓的改良的表面特 徵。應該瞭解的係，於包含鹽類添加劑的腐蚀性蚀刻劑的 本發明實作中’該餘刻劑未必如本文所述般地含有低濃度 的水及/或高濃度的氫氧化物離子源。不過，腐蝕性蝕刻劑 含有鹽類添加劑可能會呈現出本發明所涵蓋的兩項特徵中 其中一者甚至兩者。因此，於腐蝕性蝕刻劑含有鹽類添加 劑的其中一具體實施例中，該蝕刻劑中的氫氧化物離子源 的重量百分比濃度至少約為55%。 所選用的鹽類添加劑必須不會分解，也不會與該腐蚀性 蝕刻劑的其它成份（例如氳氧化物離子源）發生任何明顯的 反應。也就是，當與該腐蝕性蝕刻劑中的水或氫氧化物離 子源混合之後，該鹽類添加劑便無法逆向改變。不過，應 該瞭解的係，分解並不包括溶解，因此，於本發明的實作 88173 -23 - 200411759 中允許在與該腐蝕性蝕刻劑的其它成份混合之後將該鹽類 添加劑解離成個別的陰陽離子。 通常可從下面適當地選出該腐I虫性蚀刻劑中内含的鹽類 添加劑：無機驗金屬鹽類、驗土金屬鹽類、其水合物以及 可於預期的濃度及溫度處熔化於該腐蝕性蝕刻劑中之上述 各者的混合物。一般來說’合宜的無機鹽類包括從下面所 組成的群中選出的鹼金屬及/或鹼土金屬鹽類：鋰、鈉、钟、 鈿、铯、鈇、鈹、鎂、鈣、緦、鋇、鐳等所組成的鹽類及 其混合枚。較佳的係，該無機鹽類為鉀鹽或鈉鹽，而且以 鉀鹽為佳。可使用於本發明實作中之合宜的鉀鹽添加劑包 括：碳酸鉀、磷酸鉀、硫酸鉀、碘化鉀、氯化鉀、焦磷酸 鉀、次磷酸鉀、低磷酸鉀、正亞磷酸鉀、硝酸鉀、亞硝酸 鉀、過氧碳酸鉀、氯酸鉀、醋酸鉀、檸檬酸鉀、硼酸鉀、 氟硼酸鉀、硫酸鉀、丙酸鉀、硒酸鉀、錫酸鉀、酒石酸鉀、 石梯酸_ &氰酸舞、硫代硫酸抑、嫣酸钟、以及其混合 物。可使用於本發明實作中之合宜的納鹽添加劑包括：碳 酸鋼 '磷酸L鋼、蛾化鋼、氯化鋼、焦鱗酸納、次 磷酸鈉低磷酸鈉、正亞磷酸鈉、硝酸鈉、亞硝酸鈉、過 氧反酸#3氯酸#3、酷酸執、檸檬酸制、棚酸鋼、氟硼酸 鉀、石爪酸鈉、硫化鈉、丙酸鈉、硒酸鈉、錫酸鈉、酒石酸 #3丄綈酸鋼氨酸鋼、硫代硫酸姻、鶴酸制、以及其 混合物。此外，合宜的睡 且的鹽類添加劑還包括硫酸鎂及氫氧化 於較佳的具體實施々丨士 !中’操機鹽類添加劑包括函化鉀鹽 88173 24- 200411759 類（例如氟化鉀、碘化鉀、及/或氯化鉀）及/或碳酸鉀。於特 佳的具體實施财’該鹽類添加劑為氣化卸，於$ 一具體 實施例則為碳酸鉀。 該腐蝕性蝕刻劑中内含的任何鹽類添加劑還可能為前述 之任何换機鹽類的水合物，例如水合氟化鉀（KF2·氏〇)。 該腐蝕性蝕刻劑中的鹽類添加劑的濃度有部份係取決於 該添加劑於該規定的蝕刻溫度處溶解於該蝕刻劑溶液内其 E成份之中的溶解度。一般來說，隨著濃度的上升，於該 腐蝕性择刻劑中含有鹽類添加劑的任何有利效應便可獲得 改良。不過，該腐蝕性蝕刻劑中内含的鹽類添加劑數量較 佳的係不超過落解度上限，因而可避免於該蝕刻劑中出現 未被熔化的固體。 該腐蝕性蚀刻劑中的鹽類添加劑的重量百分比濃度通常 不超過約25%。一般來說，該鹽類添加劑的重量百分比濃度 至少約為5%，大部份的重量百分比濃度則至少約為丨〇%。 因此，該腐蝕性蝕刻劑中的鹽類添加劑的重量百分比濃度 通常係介於約5 %至約2 5 %之間；大部份的重量百分比濃度 則介於約10 %至約2 5 %之間。於鹽類添加劑包含氟化舞或碳 酸鉀任一者的情況中，該腐蝕性蝕刻劑中的鹽類添加劑的 重量百分比濃度通常不超過约25%，大部份的重量百分比濃 度皆介於約5%至約25%之間。因為合宜的鹽類添加劑的分 子重量都會大幅地改變，所以，以莫耳百分比來定義該腐 蝕性蝕刻劑中的鹽類添加劑的濃度可能比較實用。較佳的 係，該腐蝕性蝕刻劑中的鹽類添加劑的莫耳百分比濃度至 88173 -25 - 200411759 少約為1%，更佳的係莫耳百分比至少约為4%，更佳的係莫 耳百分比濃度至少約為5%，甚至莫耳百分比濃度至少約為 10%。一般來說，該腐蝕性蝕刻劑中的鹽類添加劑的莫耳百 分比度介於約4%至約1 5%之間，大部份的莫耳百分比濃 度介於約5%至約15%之間，甚至其莫耳百分比濃度介於約 10%至約15%之間。於函化鉀鹽類的情況中，該腐蝕性蝕刻 劑中的鹽類添加劑的莫耳百分比濃度至少約為1%，更佳的 係莫耳百分比至少約為4%，更佳的係莫耳百分比濃度至少 約為5% :甚至莫耳百分比濃度至少约為1〇%。一般來說， 於鹵化鉀鹽類的情況中，該腐蝕性蝕刻劑中的鹽類添加劑 的莫耳百分比濃度介於約1%至約15%之間，較佳的莫耳百 分比濃度介於約5%至約15%之間，更佳的係莫耳百分比濃 度介於約10%至約15%之間。於一較佳的具體實施例中，該 腐蚀性蝕刻劑中的鹵化鉀鹽類的莫耳百分比濃度介於約 10%至約12%之間。於碳酸鉀或氟化鉀的情況中，該腐蝕性 姓刻劑中的鹽類添加劑的莫耳百分比濃度至少約為j %，更 佳的係莫耳百分比濃度至少約為3 %。一般來說，於碳酸神 或氟化鉀的情況中，該腐蝕性蝕刻劑中的鹽類添加劑的莫 耳百分比濃度係介於約1 %至約6%之間，較佳的係莫耳百分 比濃度介於約3%至約6%之間。 較佳的係，添加至該腐蝕性蝕刻劑中的任何鹽類添加劑 都可添加至該腐蚀性蚀刻劑中的其它成份（例如水與氫氧 化物離子源的混合物）之中，作為濃縮的鹽類添加劑溶液。 鹽類添加劑溶液的較佳溶劑為水。較佳的係，該腐触性蚀 88173 -26 - 200411759 刻劑的成份經過選擇之後必須使得錢刻劑 的、單液相混合物，其中所有的成份都可溶合。—均質 於該腐蝕性蝕刻劑包括一鹽類添加劑的其中 體實施例中，該氫氧化物離子源為氫氧化納，心—2具 實施例中則為氫氧化卸。於該腐㈣㈣劑包 ::的-特佳的具體實施例中，該氫氧化物離子源二氧 化# °當該腐㈣#刻劑t内含—鹽類添加㈣，化 神便為特佳的氫氧化物離子源，因為吾人相信氫氧化卸可 減低出現_在該晶圓表面上的雜質。 於孩腐蝕性蝕刻劑包括一鹽類添加劑的具體實施例中， 孩敍刻劑的特徵為出現於該㈣劑中的氫氧化物離子的濃 度，而非該A氧化物離子的濃度。於此具體實施例中，該 蚀刻劑中的氫氧化物離子的莫耳百 > 比濃度較#的係不超 過約20%，更佳的係莫耳百分比濃度較佳的係不超過約 15%。一般來說，該蝕刻劑中的氫氧化物離子的莫耳百分比 濃度介於約5%至約15%之間，大部份的莫耳百分比濃度係 介於約10%至約15%之間。於一較佳的具體實施例中，該蚀 刻劑中的氫氧化物離子的莫耳百分比濃度介於約1〇%至約 12 %之間。 於該腐蚀性蝕刻劑包括一鹽類添加劑的具體實施例中， 該蝕刻劑中的水的莫耳百分比濃度較佳的係不超過約 85%。一般來說，該蝕刻劑中的水的莫耳百分比濃度介於約 70%至約85%之間，大部份的莫耳百分比濃度係介於約75% 至約85%之間。 88173 -27· 200411759 總體而言，當該腐蝕性蝕刻劑包括一鹽類添加劑時，所 選用的腐蝕性蝕刻劑的成份必須使得其pH值較佳的係至少 約為13 ’更佳的係介於約13.9至約14之間。 該腐蝕性蝕刻劑中内含的氫氧化物離子源、水、及任何 鹽類添加劑的純度應該至少足以進行一般的矽晶圓處理。 明確地說’較佳的係’該腐餘性姓刻劑會呈現出極低的污 染物濃度（例如每十億低於5個（ppb))，明確地說該等污染物 為鎳、銅、及鐵，用以避免污染該晶圓表面。因此，較佳 的係，該_氫氧化物離子源及任何的鹽類添加劑各都符合半 導體設備及材料國際（SEMI)標準中提及的純度曲線，而且 較佳的係，内含的任何污染物皆不超過5 ppb。 欲被進行鍅刻的矽晶圓可單獨地浸泡於該腐蝕性蝕刻劑 之中，或是同時浸泡多個晶圓。合宜的浸泡蝕刻機包括 SPEC (Valencia，加州），丁〇1!〇 (曰本）以及Dan Science (曰本） 所售的蚀刻機。雖然可同時進行蝕刻的精確晶圓數量並不 重要，不過，通常可同時蝕刻25片或更多的晶圓。依照慣 例，該等晶圓都會被固定於一旋轉籃内的卡匣中，而且該 晶圓籃可於被浸泡至該蝕刻劑中的時候同時進行旋轉。被 固定於該晶圓籃内的晶圓的旋轉速率同樣並不重要，不 過，任何的晶圓旋轉都應該足以讓該蝕刻劑盆維持被充分 攪動的狀態並且維持實質均勻的蝕刻劑溫度。一般來說， 擾動有助於造成均勻的蝕刻劑溫度。當該蝕刻劑被加熱至 合宜的溫度之後，同樣可經由該蚀刻劑與該蝕刻槽中所有 護壁的接觸結果所造成的傳導及/或對流作用來對該蝕刻 88173 •28· 200411759 劑進行冷卻。攪動可以混合具有各種溫度的部份蝕刻劑， 因此，可於該蝕刻劑接觸到該晶圓表面的所有位置處提供 更均勻的溫度。一般來說，旋轉速率介於約每分鐘i轉至約 每分鐘100轉之間。較佳的係，旋轉速率介於約每分鐘^專 至约每分鐘45轉之間，更佳的係介於約每分鐘5轉至約每分 鐘30轉之間。 一般來說，該腐蝕性蝕刻劑接觸到該蝕刻槽内之晶圓的 駐留時間（也就是，該姓刻槽的容積與該蝕刻劑的流速的比 例）至少约為2分鐘。一般來說，該蝕刻槽内之該腐蝕性蝕 刻劑的駐留時間介於約2分鐘至約24分鐘之間，大部份都介 於約2分鐘至約12分鐘之間，甚至介於約2分鐘至約4分鐘之 間。 通常可以根據欲從該晶圓表面移除的預期的碎數量來決 定該晶圓與該腐蝕性蝕刻劑接觸的時間量。欲移除的碎數 量與下面各因素形成函數關係：損壞層的厚度；於切割、 研磨及/或碾磨方法步騾期間對該晶圓所造成的機械損 壞；該等缺陷出現於該晶圓表面下方的深度；以及最終晶 圓的預期特徵。一般來說，會從該晶圓的前後面中移除總 厚度約10 μπι的材料。通常，會從該晶圓的兩面中移除總厚 度介於約10 μπι至約30 μιη的材料，大部份係介於約15 #111至 約25 μχη的材料，甚至是介於約17 μιη至約23 μιη的材料。就 前面而言，該晶圓表面與該腐蝕性姓刻劑接觸的時間通常 至少為5分鐘。通常，該晶圓表面與該腐蝕性蝕刻劑接觸的 時間係介於約5分鐘至約15分鐘，較佳的係介於約9分鐘至 88173 -29- 200411759 g 1U鐘’更佳的係介於約1G分鐘至約1〇·5分鐘，直到從該 日曰圓中移除預期的材料數量為止。 藉由測夏蔹晶圓於蝕刻前後的總厚度便可決定出實際被 移除的材料數量。當決定出特定晶圓被移除的材料數量之 =，接觸時間、蝕刻劑濃度及各項條件、晶圓繼續浸泡的 寺門等各項因子便可加以改變，用以提高或降低被移除的 科數量或者，可以監視該姓刻劑的濃度，其中該餘刻 劑中之氫氧化物離子源濃度的下降程度係直接與從該晶圓 表面中疚除的材料數量有關。因此，可以監視該蝕刻劑中 之氫氧化物離子源濃度的下降程度，並且用來預測被移除 的材料數量。可以利用熟習本技術的人士已知的任何方法 來測量蝕刻劑濃度，並且可利用下面的方法來決定，舉例 來說·利用測量該蝕刻劑之被稀釋部份的{)1^直、導電率、 或離子強度的注泥分析法，·以及對該餘刻劑之被稀釋部份 進行離子層析。亦可以利用對該蝕刻劑之被稀釋部份進行 電感輕合電漿磁光譜分析來決定蝕刻劑濃度。熟習本技術 的人士可以明白並且利用其它的方法來決定被移除的材料 數量，其並未脫離本發明的範疇（例如測量該晶圓於蝕刻前 後的重量）。 除了利用浸泡方式來讓欲被蝕刻之晶圓表面接觸到該餘 刻劑之外，應該瞭解的係，亦可以其它合宜的方法來讓欲 被姑刻之晶圓表面接觸到該腐蚀性蚀刻劑，例如利用旋轉 蝕刻方法。於旋轉蝕刻方法中，可將該晶圓的背面放置在 一旋轉夾盤上，並且在以高速旋轉該晶圓的同時將該腐蚀 88173 -30 - 200411759 性蝕刻劑喷灑於相反面上。雖然並非十分重要，不過，於 進行旋轉餘刻期間，該晶圓的旋轉速率通常會大於浸泡|虫 刻期間的旋轉速率，而且較佳的係至少約為每分鐘50轉， 更佳的係至少約為每分鐘150轉，甚至至少約為每分鐘25〇 轉。一般來說’於進行旋轉姓刻期間，該晶圓的旋轉速率 係介於約每分鐘50轉至約每分鐘650轉之間，大部份係介於 約每分鐘150轉至約每分鐘550轉之間。合宜的旋轉蝕刻機 包括SEZ (Villach，澳洲）所售的餘刻機。於進行旋轉韻刻期 間，可加-熱該旋轉夾盤，用以於整個晶圓表面上保持均勻 的溫度。 不論該晶圓表面以何種方式和該腐蝕性蝕刻劑進行接 觸，該姓刻劑都可重複使用，用以繼續蝕刻額外的晶圓。 因此，必須添加額外的水量、氫氧化物離子源數量及/或鹽 類添加劑數量至該腐蚀性蚀刻劑之中，用以置換在對先前 卵圓進抒蚀刻期間被消耗掉或損失的蚀刻劑部份。 可從該蝕刻劑中移出根據本發明來蝕刻的晶圓，並且利 用去離子水來進行沖洗。或者，亦可利用本技術中已知的 其它沖洗溶液來取代去離子水，舉例來說，過氧化氫稀釋 液（重量百分比低於3%)、以及臭氧化的去離子水。亦可利 用其它的溶液來取代去離子水，舉例來說，SC 1，其係一種 由氫氧化銨、過氧化氫、以及水所組成的標準清洗溶液。 根據本發明來蝕刻的晶圓可呈現出有利的表面特徵，若 相較於以慣用的腐蝕性蝕刻劑來蝕刻的晶圓，其包括改良 表面粗糙度；若相較於以酸性蝕刻劑來蝕刻的晶圓，經過 88173 -31 - 200411759 抛光之後，其便具有改良的平坦度及微細表面形狀。相較 於以慣用的腐蝕性蚀刻劑來蚀刻的晶圓，經過拋光之後， 根據本發明來蝕刻的晶圓可進一步呈現出改良的平坦度及 微細表面形狀。 根據本發明之具體實施例，該腐蝕性蝕刻劑中的氫氧化 物離子源的重量百分比濃度超過55%，被蝕刻後的晶圓通常 會呈現出低於約0.19 μιη Ra的平均表面粗糖度。較佳的係， 根據本發明來姓刻的晶圓可呈現出介於約〇 12 至約〇 19 μπι Ra之間的平均表面粗糙度。 利用含有上述鹽類添加劑中任一者的腐蝕性蝕刻劑來蝕 刻的晶圓通常會呈現出介於約〇· 14 μπι至約0·36 μπι Ra之間 的平均表面粗糙度，其比較接近酸性蝕刻晶圓的預期粗糙 度（通常介於約0·09 μπι至約0·16 μπι Ra之間），而且可輕易地 處理（例如利用擦光處理及/或拋光處理）成預期的粗糙度。 相較之下，利用不含重量百分比濃度超過55%之氫氧化物離 子源或鹽類添加劑的腐蝕性蝕刻劑來蝕刻的晶圓通常會具 有介於約0·27 μπι至約0·35 μιη Ra之間的平均表面粗輪度。 根據本發明來蝕刻的晶圓通常會呈現出不超過〇·8 μιη的 整體平坦度（也就是，通用背面參照指示範圍或GBIR)。一 般來說，利用含有重量百分比濃度超過55%之氫氧化物離子 源的姓刻劑來蚀刻的晶圓都會具有介於約〇·2 μιη至約〇 8 μπι之間的GBIR。一般來說，利用含有上述鹽類添加劑中任 一者的腐蝕性蝕刻劑來蝕刻的晶圓都會具有小於約0.7 μπι 的GBIR，更佳的係小於約0·5 μπι。 88173 -32 - 200411759 一般來說，根據本發明來蝕刻的晶圓通常會呈現出改良 的前表面微細表面形狀。一般來說，酸性蝕刻的晶圓會呈 現出前表面2 mm X 2 mm微細表面形狀至少約為7 5 nm，前表 面10 mm X 10 mm微細表面形狀至少約為120 nm。一般來說， 利用慣用的腐蚀性#刻劑來餘刻的晶圓會呈現出前表面2 mm X 2 mm微細表面形狀至少約為20 nm，前表面10 mm X 10 mm微細表面形狀至少約為80 nm。利用含有重量百分比濃 度超過55%之氫氧化物離子源的腐蝕性蝕刻劑來蝕刻的晶 圓則通常^會呈現出前表面2 mm X 2 mm微細表面形狀小於約 20 nm ;大部份則係介於約10nm至約20nm之間。以此方式 來姓刻的晶圓通常還會呈現出前表面10 mm X 10 mm微細表 面形狀小於約40 nm ;大部份則係介於約25 nm至約40 nm之 間。一般來說，利用含有上述鹽類添加劑中任一者的腐银 性姓刻劑來姓刻的晶圓會呈現出前表面2 mm X 2 mm微細表 面形狀小於約15 nm ;大部份則係介於約7 nm至約1 5 nm之 間。以此方式來蚀刻的晶圓通常還會呈現出前表面10 mm X 10 mm微細表面形狀小於約35 nm ;大部份則係介於約25 nm 至約35 nm之間。 利用酸性或腐蝕性蝕刻劑來蝕刻的矽晶圓還可以部位平 坦度的最小平方範圍（部位平坦度，或SFQR)(SEMI Ml-1296) 作為特徵，其為以具有已定義大小（例如20 χ 20 mm的部位） 之晶圓表面上特殊部位内之一連串位置點為基礎的最小平 方配適平面和該晶圓表面實際高度之間的差異。可以利用 ADE容量測量法（例如ADE 9600平坦度處理站）來決定一特 88173 -33 200411759 殊部位的SFQR值。矽晶圓具有許多個20 χ 20 mm大小的部 位。舉例來說，直徑為200mm的矽晶圓將會具有52個20 X 20 mm的部位，因此將會有52個SFQR測量值。可以利用晶圓表 面上該等複數個部位的SFQR測量值的平均值（部位平坦度 平均值，或SFQRavg)或是該晶圓的最大SFQR測量值（部位 平坦度最大值，或SFQRmax)來表示一特殊晶圓的部位平坦 度值。亦可利用該晶圓表面上所有部位的SFQR測量值來表 示一特殊晶圓的整體的部位平坦度分佈情形，稱為該晶圓 的「全部-位」SFQR資料。亦可以預設數量之晶圓上的部位 來表示SFQRavg、SFQRmax及全部位SFQR資料（例如由100 片晶圓所組成的集合，如果各具有52個部位的話，其便含 有5200個部位的SFQR測量值）。舉例來說，可以繪製出由100 片晶圓所組成的集合之所有部位的SFQR測量值，並且以部 位平坦度低於特定值（Y)之晶圓部位（X)的百分率來表示全 部位資料。 區分出整個晶圓表面的平坦度（即GBIR)和該晶圓表面上 之特殊部位的平坦度（即SFQR)相當地有用，因為被放置在 該晶圓表面針對特殊用途來設計的個別的積體電路或一群 積體電路的大小通常約為一個20 X 20 mm部位。適合納入積 體電路的個別部位通常都需要有約0.13 μιη的特定最小部位 平坦度。因此，裝置製造商可以利用SFQR值來決定各項特 殊應用的晶圓的合適性。 根據本發明，吾人已經發現，除了改良的整體平坦度之 外，相較於以酸性蚀刻劑及慣用的腐触性蚀刻劑來触刻的 88173 -34- 200411759200411759 (ii) Description of the invention: [Technical field to which the invention belongs] The present invention generally relates to a method for etching a silicon wafer using a corrosive etchant. The invention further relates to a method for etching a silicon wafer for manufacturing a silicon wafer having improved surface characteristics such as flatness and fine surface shape. [Prior art] The following multiple steps are usually used to obtain a silicon wafer: the silicon block is sliced into thin slices in the direction perpendicular to the axis of a single crystal dicing block to produce a thin wafer, cut or scribed Remove the edges of the wafers; grind or mill the wafers to remove surface damage caused by the slicing method; chemically etch the wafers to remove the previous shaping steps The resulting mechanical damage; and finally, the edges are chemically / mechanically polished, and at least one side of each wafer is provided with colloidal ground mud and chemical tincture 'to ensure that The wafer has a very flat, reflective and undamaged surface. These wafers can then usually be cleaned and quality checked before packaging. Silicon wafers often exhibit surface defects and / or subsurface defects (implanted particles) before chemical etching, and physical damage (such as damage to the wafer caused by grinding, grinding, and edge tracing). Micro-cracks, cracks or stresses). These defects usually occur in an area of at least about 2.5 μπχ on the wafer side. Therefore, in order to remove the defects from the surface to the wafer surface, at least about 2.5 ㈣ of silicon must be removed from the wafer surface using an acidic and / or corrosive chemical etchant in order to remove the implants. Particles, contaminants, 88173 200411759 and the physical damage contained in the removed silicon layer. Both acidic and corrosive chemical etchants can be used to etch the surface of silicon wafers. One of the most common acidic etchant chemical formulas includes an aqueous solution consisting of hydrofluoric acid (HF), acid (HNO3), and water. Corrosive primers usually contain more than one alkali metal hydroxide, such as potassium hydroxide (KOH) or sodium hydroxide (NaOH), and water. Compared to a wafer etched with a corrosive etchant, in some examples, an acidic etchant is a better choice because it usually produces a smooth wafer surface, with a lower surface roughness. However, acidic etchant can easily generate unnecessary gas and solid phase chemicals on the surface being etched on the wafer, form stains, hinder further reactions to the understanding system, and produce inconsistent etching results (see "An Examination of the Chemical Staining of Silicon" by DG Schimmel et al., L Electrochem. Soc., 1978 (Vol. 125, pp. 152-155). The acidic etchant containing nitric acid will react during the etching method to produce toxic gases containing nitrogen oxides. Because these gases are toxic to the human body, they must be safely controlled and special treatment procedures must be adopted. To avoid polluting the environment and comply with environmental management regulations. In addition, in order to obtain a very smooth surface using an acidic etchant, a large amount of silicon must be removed from such silicon wafers, typically about 10 to 15 μm must be removed from the front and back surfaces of the wafer. In general, it is best to limit the amount of debris that is removed from the surface of the wafer so that the variation in wafer thickness can be limited. Acidic etchants can usually etch the wafer at very high etch rates, and 88173 200411759 mainly controls the etch rate by the mass transfer of the reactants to the wafer surface. During the mass transfer type etching method, since it is difficult to precisely control the removal process of silicon, the flatness of the wafer subjected to acid etching is deteriorated. At the same time, when the rapid mass transfer type acid etching method encounters the masking of bubbles (that is, the gaseous etching reaction by-products attached to the surface of the wafer, such as hydrogen, NOx), it is easy for the wafer to be etched. There is a noticeable change in the fine surface shape. (See "Acid-Based Etching of Silicon Wafers: Mass-Transfer and Kinetic Effects" by K. Electrochem. Soc., 2000, by Kulkarni et al., Vol. 147 (1), pp. 176-188) Corrosive etchant has several advantages over acidic etchant. For example, compared to wafers etched with acidic surrogates, humic contact etchants are easier to produce wafers with a flat surface, and only very simple etching equipment is required. In general, the etching rate of a corrosive etchant is slower than that of an acidic etchant, and the etching method is mainly controlled by reaction kinetics, not by the mass transfer of the reactants to the wafer surface. We want to be able to limit the amount of silicon that is removed from the surface during chemical etching so that we can limit variations in wafer thickness or flatness. As the amount of silicon removed from these wafer surfaces increases, the general back-reference indication range (GBIR) (the difference between the maximum and minimum thickness of the wafer) typically increases as well. Corrosive etchant typically produces wafers with low GBIR (e.g., about +0.1 μm), while acidic etchant typically produces crystals with high GBIR (e.g., between + 0 · 5 to +1.5 μm) circle. Compared to acid-etched wafers, it is better to use a corrosive etching solution in this regard, because 88173 200411759 only has to remove very few pieces of debris from the surface of these wafers during subsequent processing. Achieving a satisfactory GBIR. Furthermore, since the etch rate of the etched etchant is low, it is relatively easy to reduce the density of gaseous by-products containing bubbles attached to the surface of the wafer. Decreasing the number of bubbles appearing on the surface of the wafer can reduce the "bubble masking" effect on the fine surface shape of the wafer. Therefore, even if bubbles are formed on the surface of the wafer, because the reaction kinetics can be used to control the method, the fine surface shape of the etched wafer is usually more consistent than that of an acid-etched wafer. In addition to providing etched wafers with improved surface characteristics, such as flatness and fine surface shape, basically, the surname surname engraving method is safer and can be operated at a lower cost than the acid etching method. The amount of any gaseous by-products due to corrosive etching methods is usually very low, so they can be disposed of safely and simply. For example, the amount of any hydrogen produced is usually below its lower explosive limit and can be safely and easily disposed of. Corrosive etchant reacts with surface tissue more slowly than acidic etchant reacts with surface tissue. Therefore, compared to acidic etchant, it is a danger to operators when accidentally exposed to corrosive etchant. Sex will be lower. However, corrosive etchant is not superior to acidic etchant in every respect. As mentioned earlier, the surface roughness of an acid-etched wafer will be lower than that of an etched wafer. In general, the average surface roughness (Ra) of a wafer manufactured by an acidic etching method is between about 0.09 μm to 0.16 μηι, and the average surface roughness of a wafer manufactured by an etching method is about Between 0.27 μm to 0.35 μm Ra. The reason why the coarse chain degree of the corroded etched wafer is larger than 88173 -10- 200411759 is that most of them are etched preferentially along the crystallographic plane of the small crystal plane that can produce the appearance characteristics of "fish scale". The subsequent polishing treatment can overcome the high surface roughness and small crystal plane caused by the conventional corrosive etchant, but the time required to polish the front surface and edge surface of the wafer will be rough due to the surface. Degrees have increased substantially. Therefore, compared to wafers subjected to acid etching, the high surface roughness and small crystal planes in the wafers subjected to the etched etch process will reduce the production cost and the cost of the positive implant method. In addition, sometimes the surface roughness is too large, so that device manufacturers (which can specify the "etched" backside of the wafer) cannot double the corroded wafer because they still have to use it before using the wafer. This back must be treated further. Therefore, 'there has always been a need for a corrosive etching method capable of manufacturing wafers' so that such wafers can easily exhibit the desired standard surface characteristics after processing. SUMMARY OF THE INVENTION Therefore, the various objects of the present invention are: to provide an improved corrosive etchant for removing silicon from the surface of a silicon wafer; and to provide a method for etching a silicon wafer using a corrosive etchant, Compared with a wafer etched with an acidic etchant, it can produce an etched wafer with improved flatness and a fine surface shape; a method for smashing a wafer by using a humic etchant is provided, so that Compared to wafers etched with conventional corrosive etchants, it can produce etched wafers with improved surface characteristics; a method for etching silicon wafers with corrosive etchants is provided, which is compared with conventional etched silicon wafers. Wafers etched with a corrosive etchant can produce etched wafers with a small surface roughness 88173 -11-200411759; provide a rotten wafer etchant method for broken wafers, which can improve the yield of subsequent polishing steps Provide a method for etching a silicon wafer, which has enhanced security features compared to a method for etching a silicon wafer with an acidic etchant; and provide a corrosive etchant An etching method for a wafer pieces, which may reduce the number of poison shed and / or reduce the environmental control costs. So 'to put it simply', the present invention relates to an etching method for removing silicon from the surface of a hard wafer, which includes sputum contacting the surface of the silicon wafer with a corrosive etchant in the form of an aqueous solution, the aqueous solution containing Water and hydroxide ion source. The weight percentage concentration of water in the corrosive etchant is less than 45%. In another embodiment, the weight percentage concentration of the hydroxide ion source in the corrosive etchant that contacts the surface of the silicon wafer is higher than 55%. In another specific embodiment, the concentration of the hydroxide ion source in the corrosive etchant in contact with the surface of the silicon wafer is at least about 70% of the saturation concentration of the hydroxide ion source in the corrosive etchant. . In another embodiment, the etching method for removing silicon from the surface of a silicon wafer includes contacting the surface of the silicon wafer with a corrosive etchant in the form of an aqueous solution. The aqueous solution contains water and hydroxide. Ions, and salt additives that do not decompose or react in this rotten family name. The salt additive includes a compound selected from the group consisting of: inorganic alkali metal salts, alkaline earth metal salts, and mixtures thereof; and the molar additive concentration of the salt additive in the corrosive etchant is at least about 4%. In another embodiment, 88173-12-12200411759 is used to remove broken wafers from the surface of the wafer. The method includes contacting the broken wafer surface with an etch etchant in the form of an aqueous solution. Containing water, hydroxide ions, and salt additives, the salt additives include compounds selected from the group consisting of potassium carbonate and potassium fluoride. The salt additive in the corrosive etchant has a molar percentage concentration of at least about 10/0. The invention further relates to a corrosive etchant for etching a silicon wafer, which comprises an aqueous solution containing water, hydroxide ions, and a salt additive that does not decompose or react in the corrosive etchant. . The argon-based additive includes a compound selected from the group consisting of inorganic alkali metal salts, alkaline earth metal salts, and mixtures thereof, and the molar percentage concentration of the salt additive in the corrosive etchant is at least about 4%. In another embodiment, the corrosive etchant used to etch a silicon wafer includes an aqueous solution including water, hydroxide ions, and a salt additive. The salt additive includes a group consisting of the following: Selected compounds: potassium carbonate and potassium fluoride. The molar additive concentration of the salt-based additive in the corrosive etchant is at least about 10/0. The invention further relates to a single crystal silicon wafer, which includes a central axis, front and rear surfaces generally perpendicular to the central axis, a peripheral edge, and a radius R (which extends from the central axis to the peripheral edge of the wafer). ). After polishing, the average flatness of the front surface portion of the single crystal chipped wafer is less than about 0.013 μm, the maximum flatness of the front surface portion is less than about 0.018 μm, and the fine surface shape of the front surface 2 mm X 2 mm is less than about 20 nm The fine shape of the front surface 10 mm X 10 mm is less than about 40 nm. 88173 • 13-200411759 Other objects and features of the present invention will be apparent from the following description. [Embodiment] A corrosive etching method capable of manufacturing a silicon wafer having improved surface characteristics has been discovered. The method of the present invention provides recognized advantages in corrosive etching, which can overcome or minimize recognized limitations in conventional corrosive etching and acid etching. Compared to wafers etched with conventional corrosive etchant, the wafers etched by the present invention will exhibit less surface roughness; and compared with wafers etched by acid etching, The wafers etched by the invention will also exhibit higher flatness and lower fine surface shape changes after polishing. Compared with wafers etched by conventional etch etchants, the wafers etched by the present invention will further exhibit higher flatness and lower changes in fine surface shapes. The corrosive etchant used in the present invention is a type of an aqueous solution including water and a source of hydroxide ions. In one embodiment, the corrosive etchant is generally characterized by a lower concentration of water than previously used. In another specific embodiment, an additional or alternative feature of the corrosive etchant is that the concentration of the hydroxide ion source is higher than the previously used concentration. In another specific embodiment, the corrosive etchant includes Salt additives. The method of the present invention uses a silicon wafer as a raw material. The silicon wafer is cut from single crystal fragments and further processed, for example, using conventional grinding equipment to trace or cut out the periphery of the wafer. edge. This process can reduce the risk of wafer damage during further processing, reduce uneven sentence damage caused by the dicing process, and roughly improve the general flatness and parallelism of the front and rear surfaces. Any method known to those skilled in the art can be used to cut the wafer from the silicon block, for example, inside diameter cutting equipment and micro saw cutting equipment. Grinding is a method well known to those skilled in the art. A typical grinding method can generally use resin adhesives, 1200 to 6,000 toothed grinding wheels operating at about 2000 RPM to about 4000 RPM to remove about 20 μm to about 30 from each surface of the wafer. μm material in order to roughly improve the flatness. In addition to the grinding method, the following mills can be used to mill the wafers: AC 1200, AC 1400: AC 1500 rotary mills manufactured by Peter Wolters AG (Ransburg, Germany); or Mills manufactured by SpeedFamKK (Japan) or Fujikoshi (Japan). A suitable milled sandy soil with a fine surface shape Al203 abrasive, such as F0_1200, PWA 9, or PWA 11M manufactured by Fujimi America, Inc. (Wilsonville, OR). If these wafers are to be milled in addition to grinding, the order of the mechanical shaping methods is not important. The silicon wafer can have any conductivity, resistivity, diameter, and target thickness for the intended semiconductor application. For example, the diameter is generally at least about 100 mm, usually 150 mm, 200 mm, 300 mm or more, and the thickness is between about 475 μm to about 900 μm, and the thickness usually increases as the diameter increases increase. The wafer may also have any crystalline orientation. However, in general, these wafers have < 1〇〇 > and < 111 > Crystal orientation. After being cut from the silicon block and subjected to the mechanical shaping processes described above, the wafer typically exhibits surface and / or subsurface defects (such as implanted particles) and physical damage (such as micro-cracks, cracks, or stress) . These defects 88173 -15- 200411759 usually occur in the area from the wafer surface to at least about 2.5 μm below the wafer surface. In addition, the average surface rough chain degree of the wafer surface is usually between at least about 50 nm and about 200 nm Ra or more. Surface roughness can be measured using any measuring device capable of measuring surface roughness. Those skilled in the art are aware of these devices. For example, you can use the MP 3000 surface measuring device sold by Chapman Instruments (Rochester, NY, USA) to measure surface roughness, or use the following other measuring devices, such as: AFM microscope, Nomarski 50X magnification Microscope, 10X magnification Wyko-2D microscope, optical interferometer, or Federal Products Surface Analyzer manufactured by former Federal Products, Inc. (now known as Mahr Federal, Inc. (Providence, Rhode Island)) 5000 ° Then, the shaped wafers can be chemically etched to substantially reduce these mechanical defects. According to the present invention, a corrosive etchant in the form of an aqueous solution can be used, which contains water and a source of hydroxide ions. As detailed below, the corrosive etchant may further include a salt additive. Although the method of the present invention may use only the corrosive etchant described herein for etching, it should be understood that the corrosive etchant disclosed herein can also be applied to the use of acidic etchant and / or other corrosion Etch guidelines for multiple steps of an alkaline etchant. According to one embodiment of the present invention, the concentration of water in the aqueous solution of the corrosive etchant is lower than that of a conventional corrosive etchant. More specifically, the concentration of water in the corrosive etchant is less than 45% by weight. The latest experiments prove that compared with 88173 -16-200411759 wafers etched with conventional corrosive etchant, wafers etched with the corrosive etchant of the present invention have less surface roughness; and Compared with a wafer etched with an acidic etchant and a conventional corrosive etchant, the wafer etched with the corrosive etchant of the present invention also has improved flatness and fine surface shape. We believe that these improved surface characteristics are due, at least in part, to increasing the surface tension of the corrosive etchant when the weight percent concentration of water in the corrosive etchant is less than 45%. Increasing surface tension reduces the average size of bubbles that appear on the wafer surface during the implementation process. Because I believe that the size of the small crystal plane is determined at least in part by the size of the bubbles on the surface of the wafer. Reducing the size of the bubbles on the surface of the wafer can reduce the gas / envelope. The surface is more uniformly etched. I believe that the more uniform etching of the wafer surface is at least partly due to the smaller contact angle between the small bubbles and the surface of the wafer seen when the surface tension of the etch 2> 1 d is raised. A smaller contact angle reduces the size of the wafer surface that directly contacts each individual bubble, providing a more uniform etched wafer surface. I further believe that the improved surface features of these etched wafers 6 because the decrease in the concentration of water in the corrosive etchant will slow down the relationship of the oxidation rate during the etching process. The silicon etching can be performed by a two-step method. The silicon oxide is oxidized with water in the etchant, and the silicon dioxide is dissolved by using an alkali metal component in a hydroxide ion source in the etchant. Therefore, lowering the water concentration will slow down the oxidation rate and thus the etch rate.彳 More precisely, the improved surface characteristics that caused the slowdown in the total oxidation rate can be reduced by 88173 • 17- 200411759. < 100% > caused by preferential etching in the crystal plane. To be clear, someone has discovered that < 100 > The etching rate in the crystal plane was reduced by 40%. < 100 > The effect of the etching rate reduction in the crystal plane is most pronounced 'because the etching rates in these planes are greater than those in all other planes. because < 100 > The difference between the etch rate in the crystal plane and the etch rate in all other wafer surfaces is reduced, so the small crystal plane phenomenon and roughness associated with it can also be reduced. Generally speaking, < 100 > The ratio of the etch rate in the crystal plane and all other wafer surfaces is approximately between 7 and 5. According to the present invention, the preferred ratio of the etch rate in the $ 100 > crystal plane and all other wafer surfaces is close to one. The corrosive etchant will usually include at least about 10% by weight of water 'and even at least about 20% by weight of water, and at least about 25% by weight of water. Preferably, the corrosive etchant includes water in an amount of between about 25% and about 45% by weight; more preferably, it includes water in an amount of between about 30% and about 42% by weight; even It includes water in a weight percentage between about 30% and about 37%. In certain examples, it may be practical to define the concentration of water in the corrosive etchant as a percentage of mole. Therefore, the mole percentage concentration of water in the corrosive etchant typically does not exceed about 68%. Generally speaking, the mole percentage concentration of water in the corrosive etchant usually does not exceed about 65%; most of the mole percentage concentration does not exceed about 55%; and even the mole percentage concentration does not exceed about 45%. . A preferred system has a molar percentage of water in the corrosive etchant of between about 5% and about 45%; a more preferred system is between about 5% and about 20%. 88173 -18- 200411759 Increasing the concentration of the hydroxide ion source in this humic etchant will achieve the expected lower water concentration. According to a specific embodiment of the present invention, the weight percentage concentration of the hydroxide ion source in the corrosive etchant will be greater than 55%. Preferably, the weight percent concentration of the hydroxide ion source in the degradable surname is at least about 57%; more preferably, the weight percent concentration is at least about 58%; and the more preferred weight percent concentration is at least about 57%. About 60%; even better is a weight percent concentration of at least about 62%. According to one embodiment of the present invention, the concentration of the hydroxide ion source in the corrosive etchant- is at least about 65% by weight. /. . Generally, the concentration of the hydroxide ion source in the corrosive etchant will not exceed about 75% by weight. Therefore, the weight percent concentration of the hydroxide ion source in the corrosive etchant is usually between about 58% and about 70%; more preferably, the weight percentage concentration is between about 58% and about 65%. Between; more preferably, a weight percent concentration between about 62% and about 65%. Suitable sources of hydroxide ions include tetramethylammonium hydroxide and hydroxides of alkali metals (such as sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, and mixtures thereof). In a preferred embodiment, the hydroxide ion source includes 4A hydroxide; in another preferred embodiment, it includes a hydroxide ornament. I have found that when using sodium hydroxide as a source of hydroxide ions, the effect of reducing the bubble size and increasing the surface tension by using a corrosive etchant with a low concentration of water to reduce the size of the small crystal plane and the surface coarseness More significant. Therefore, in a preferred embodiment, the hydroxide ion source will include sodium hydroxide. In a specific embodiment, the hydroxide 88173 -19- 200411759 ion source includes sodium hydroxide, and the weight percentage concentration of sodium hydroxide in the corrosive etchant is at least about 58%; more preferably, the weight percentage concentration is At least about 61%; even better is a weight percent concentration of at least about 62%. Generally, the concentration of ' sodium hydroxide does not exceed about 68%. Therefore, the weight percentage concentration of sodium hydroxide in the rotten sex name is usually between about 58% and about 68%; more preferably, the weight percentage concentration is between about 58/0 and about 63. %; More preferably, the weight percentage concentration is between about 61/0 and about 63%. Although sodium hydroxide is a better source of hydroxide ions, it should be a solution-based system. Other hydroxide ion sources (such as potassium hydroxide y) that are more than 55% by weight can also be provided. Advantageous results discussed herein. In one specific embodiment, the source of hydroxide ions includes potassium hydroxide, and the weight percent concentration of potassium hydroxide in the corrosive etchant is at least about 57%; better system weight The percentage concentration is at least about 60%. Generally, the weight percentage concentration of potassium hydroxide does not exceed about 63%. Therefore, the weight percentage concentration of potassium hydroxide in the corrosive etchant is usually between about 57% and about 63%; preferably, the weight percentage concentration is between about 60% to about 63%. In specific examples (for example, as in the case of a corrosive etchant containing a salt additive), when the corrosion residue is When the composition of the sex name engraving agent has various molecular weights), it may be practical to define the concentration of the hydroxide ion source in the corrosive etchant as a percentage of moles. Therefore, the sex name The molar percentage concentration of the hydroxide ion source in the etchant usually does not exceed about 70%. In general, the molar percentage concentration of the hydroxide ion source in the corrosive etchant usually does not exceed about 68 ° / Most of the mole percentage concentration 88173 -20-200411759 does not exceed about 55%; even the percentage mole concentration does not exceed about 45%. Generally, the mole of the hydroxide ion source in the corrosive etchant The ear percentage concentration is usually between about 30% and about 45%. In the case of a corrosive etchant in which the hydroxide ion source includes sodium hydroxide, the mole percentage of the steel hydroxide in the corrosive etchant The concentration usually does not exceed about 55%. Generally speaking, in this embodiment, the molar percentage concentration of sodium hydroxide in the corrosive etchant is at least about 35%, and most of the molar percentage concentration is Between about 40% and about 50%. Further according to this specific embodiment, the molar percentage concentration of water in the corrosive after-treatment agent typically does not exceed 68%. When the hydroxide ion source includes hydrogen Corrosive etchant when potassium oxide The molar percentage concentration of hydrogen hydroxide is usually not more than 55%. Generally, in this specific embodiment, the molar percentage concentration of potassium hydroxide in the corrosive etchant is at least about 30%, and most The molar percentage concentration of parts is between about 30% to about 40%. Further according to this embodiment, the molar percentage concentration of water in the corrosive etchant is generally not more than. According to the present invention, In a preferred embodiment, the concentration of the hydroxide ion source in the corrosive etchant is at or near a saturation point at a predetermined etching temperature. When the temperature of the corrosive etchant rises, The concentration of the source of hydroxide ion will generally increase with it. However, it should be understood that the better concentration of the source of hydroxide ion in the corrosive etchant should not be improved to form unexpected precipitation. The concentration point of the substance. That is, when preparing the corrosive etchant (which contains water and hydroxide ion source, and any other ingredients), it is better to allow the etchant to have a specified surname at a temperature that can cause damage to the soluble compound. The mixture includes a homogeneous single liquid phase mixture. This system is better than 88173 -21-200411759 to avoid the formation of deposits, because any generated sinks may adhere to or form on the surface of the wafer, thus disturbing the brain engraving process, and the etched crystals The fine shape of the round surface has a negative effect. The appearance of sunken objects in the corrosive finish can also cause operational problems, such as blocking process equipment or interfering with temperature control of the etchant. In one embodiment of the present invention, the concentration of the hydroxide ion source in the corrosive etchant may be defined as that the hydroxide ion source in the corrosive etchant is at least about 7 at a predetermined etching temperature. 0% saturation, more preferably-at least about 74%, even more preferably at least about 77%. However, in order to reduce the risk of formation of sinkers, the concentration of the hydroxide ion source in the corrosive etchant usually does not exceed about 95% of the saturated concentration of the hydroxide ion source in the corrosive etchant. . Therefore, the concentration of the hydroxide ion source in the corrosive etchant is usually between about 70% and about 95% of the saturated concentration of the hydroxide ion source in the corrosive etchant. between. In a preferred embodiment, the concentration of the hydroxide ion source in the corrosive etchant is usually between about 74% and about 90% of the hydroxide ion source in the corrosive etchant. % Saturation concentration. In another preferred embodiment, the concentration of the source of hydroxide ions in the corrosive etchant is usually between the source of hydroxide ions in the corrosive etchant at about the specified etching temperature. Between 74% and about 81% saturation. In the practice of the present invention, the temperature of the corrosive etchant will generally be maintained at a temperature of at least about 70 ° C, and most of it will be maintained at a temperature of at least about 75 ° C 'or even at a temperature of at least about 80t. . In one embodiment of the present invention 88173 -22- 200411759, the temperature of the corrosive etchant is maintained at a temperature of at least about 90 ° C; in another embodiment, the temperature of the corrosive etchant is maintained at least about 100 . 〇Temperature. The temperature of the corrosive etchant is generally maintained between about 70 ° C and about 120 ° C. The preferred system is maintained between about 70 ° C and about 110 ° C, and the more optimal system is maintained at about 70 °. Between about 100 ° C and about 100 ° C, and more preferably between about 75 ° C and about 90 ° C, and even between about 75 ° C and about 85t. When the corrosive etchant contains a salt additive, a higher temperature in the above range (for example, between about 100 ° C to about 120 ° c) can be used for the corrosive etchant to help dissolve the M Additives. It should be understood, however, that the aforementioned preferences generally apply regardless of whether the corrosive etchant includes a salt additive. As described above, the humic surname etcher used in the practice of the present invention may include a salt-type additive, which helps to produce improved surface characteristics of the etched wafer. It should be understood that in the practice of the present invention including a corrosive etchant containing a salt additive, the remainder does not necessarily contain a low concentration of water and / or a high concentration of a hydroxide ion source as described herein. However, the corrosive etchant containing salt additives may exhibit one or even two of the two features covered by the present invention. Therefore, in one embodiment where the corrosive etchant contains a salt additive, the concentration of the hydroxide ion source in the etchant is at least about 55% by weight. The selected salt additives must not decompose and do not react in any significant way with the other components of the corrosive etchant, such as the hafnium oxide ion source. That is, when mixed with a source of water or hydroxide ions in the corrosive etchant, the salt additive cannot be reversed. However, it should be understood that decomposition does not include dissolution. Therefore, the implementation of the present invention 88173 -23-200411759 allows the salt additives to be dissociated into individual yin and yang after mixing with other ingredients of the corrosive etchant. ion. The salt additives contained in the rotten insecticidal etchant can usually be appropriately selected from the following: inorganic metal test salts, soil test metal salts, hydrates thereof, and can be melted in the corrosion at the expected concentration and temperature A mixture of the above-mentioned various etching agents. In general, 'suitable inorganic salts include alkali metal and / or alkaline earth metal salts selected from the group consisting of: lithium, sodium, bell, rubidium, cesium, rubidium, beryllium, magnesium, calcium, rubidium, barium And radium and their mixed pieces. Preferably, the inorganic salt is a potassium salt or a sodium salt, and more preferably a potassium salt. Suitable potassium salt additives that can be used in the practice of the present invention include: potassium carbonate, potassium phosphate, potassium sulfate, potassium iodide, potassium chloride, potassium pyrophosphate, potassium hypophosphite, potassium hypophosphate, potassium orthophosphite, potassium nitrate , Potassium nitrite, potassium peroxycarbonate, potassium chlorate, potassium acetate, potassium citrate, potassium borate, potassium fluoborate, potassium sulfate, potassium propionate, potassium selenate, potassium stannate, potassium tartrate, lithiarate Dance of cyanic acid, thiosulfuric acid, bell acid, and mixtures thereof. Suitable sodium salt additives that can be used in the practice of the present invention include: carbonic acid steel 'phosphate steel, moth steel, chlorinated steel, sodium pyroscale, sodium hypophosphite, low sodium phosphate, sodium orthophosphite, sodium nitrate , Sodium nitrite, peroxy inverse acid # 3chloric acid # 3, cool acid, made of citric acid, shed acid steel, potassium fluoborate, sodium claw, sodium sulfide, sodium propionate, sodium selenate, stannic acid Sodium, tartrate # 3 gallate steel, thiosulfuric acid, made from crane acid, and mixtures thereof. In addition, suitable salt additives also include magnesium sulfate and hydroxide in the preferred embodiment. The salt additives include potassium salts 88173 24-200411759 (such as potassium fluoride, Potassium iodide and / or potassium chloride) and / or potassium carbonate. In the specific embodiment of Yu Tecai, the salt additive is degassed, and in a specific embodiment, it is potassium carbonate. Any salt additive contained in the corrosive etchant may also be a hydrate of any of the aforementioned switch salts, such as hydrated potassium fluoride (KF2 · ° 0). The concentration of the salt-based additive in the corrosive etchant depends in part on the solubility of the additive in its E component in the etchant solution at the specified etching temperature. In general, as the concentration increases, any beneficial effects of salt additives in the corrosive selective agent can be improved. However, the better the amount of the salt additives contained in the corrosive etchant does not exceed the upper limit of the degree of dissolution, so that unmelted solids can be avoided in the etchant. The concentration of the salt additive in the corrosive etchant usually does not exceed about 25%. Generally speaking, the concentration of the salt additive is at least about 5% by weight, and most of the concentration by weight is at least about 0%. Therefore, the weight percentage concentration of the salt additives in the corrosive etchant is usually between about 5% and about 25%; most of the weight percentage concentration is between about 10% and about 25%. between. In the case where the salt-based additive comprises any of fluoride fluoride or potassium carbonate, the concentration of the salt-based additive in the corrosive etchant usually does not exceed about 25%, and most of the weight-% concentration is between about Between 5% and about 25%. Because the molecular weight of a suitable salt additive can vary greatly, it may be practical to define the concentration of the salt additive in the corrosive etchant in terms of mole percentages. Preferably, the molar percentage concentration of the salt additives in the corrosive etchant is 88173 -25-200411759, which is less than about 1%, and the better molar ratio is at least about 4%. The ear percentage concentration is at least about 5%, and even the mole percentage is at least about 10%. Generally speaking, the molar percentage of the salt additives in the corrosive etchant is between about 4% and about 15%, and most of the molar percentages are between about 5% and about 15%. In the meantime, even its mole percentage concentration is between about 10% to about 15%. In the case of potassium salts, the molar concentration of the salt additives in the corrosive etchant is at least about 1%, a more preferred molar ratio is at least about 4%, and a more preferred molar ratio is about 4%. The percentage concentration is at least about 5%: even the mole concentration is at least about 10%. Generally, in the case of potassium halide salts, the molar percentage concentration of the salt additives in the corrosive etchant is between about 1% and about 15%, and the preferred molar percentage concentration is between about 1% and about 15%. Between 5% and about 15%, more preferably the mole concentration is between about 10% and about 15%. In a preferred embodiment, the molar percentage concentration of potassium halide salts in the corrosive etchant is between about 10% and about 12%. In the case of potassium carbonate or potassium fluoride, the molar percentage concentration of the salt additives in the corrosive surname is at least about j%, and more preferably, the molar percentage concentration is at least about 3%. In general, in the case of carbonic acid or potassium fluoride, the molar percentage concentration of the salt additives in the corrosive etchant is between about 1% and about 6%, and the preferred molar percentage is The concentration is between about 3% and about 6%. Preferably, any salt additive added to the corrosive etchant can be added to other components of the corrosive etchant (such as a mixture of water and a hydroxide ion source) as a concentrated salt. Class additive solution. A preferred solvent for the salt-based additive solution is water. In a preferred system, the corrosion-resisting etch 88173 -26-200411759 is selected after the ingredients of the etchants have to be made into a single-liquid phase mixture of the etchants, all of which are soluble. -Homogeneous In the embodiment in which the corrosive etchant includes a salt-type additive, the source of the hydroxide ion is sodium hydroxide, and in the embodiment of the second embodiment, the hydroxide is removed. In the specific embodiment of the rotten tincture package ::-Extremely good, the hydroxide ion source dioxide # ° When the rotten #etcher is contained in the salt-addition of salt, it is particularly good The source of hydroxide ions, because I believe that the unloading of hydroxide can reduce the impurities appearing on the wafer surface. In a specific embodiment where the caustic etchant includes a salt-based additive, the caustic is characterized by the concentration of hydroxide ions present in the tincture, rather than the concentration of the A oxide ions. In this embodiment, the molar ratio of the hydroxide ions in the etchant is less than about 20%, and the better concentration is less than about 15%. %. Generally speaking, the molar percentage concentration of hydroxide ions in the etchant is between about 5% and about 15%, and most of the molar percentage concentration is between about 10% and about 15%. . In a preferred embodiment, the molar concentration of hydroxide ions in the etchant is between about 10% and about 12%. In a specific embodiment in which the corrosive etchant includes a salt-based additive, the molar percentage concentration of water in the etchant is preferably not more than about 85%. Generally, the molar percentage concentration of water in the etchant is between about 70% and about 85%, and most of the molar percentage concentration is between about 75% and about 85%. 88173 -27 · 200411759 In general, when the corrosive etchant includes a salt additive, the composition of the corrosive etchant used must be such that its pH value is better than at least about 13 ′. Between about 13.9 and about 14. The source of hydroxide ions, water, and any salt additives contained in the corrosive etchant should be at least sufficient for general silicon wafer processing. It is clearly stated that the "better system" of the surviving surname will show extremely low concentrations of pollutants (for example, less than 5 per billion (ppb)). It is clear that these pollutants are nickel and copper. , And iron to avoid contaminating the surface of the wafer. Therefore, the better system, the _ hydroxide ion source and any salt additives each meet the purity curve mentioned in the International Standard for Semiconductor Equipment and Materials (SEMI), and the better system contains any pollution Nothing exceeds 5 ppb. The silicon wafers to be etched can be individually immersed in the corrosive etchant, or multiple wafers can be immersed simultaneously. Suitable immersion etchers include etchers sold by SPEC (Valencia, California), Dingol (Japanese) and Dan Science (Japanese). Although the exact number of wafers that can be etched at the same time is not important, usually 25 or more wafers can be etched simultaneously. By convention, the wafers are fixed in a cassette in a rotating basket, and the wafer basket can be rotated at the same time when immersed in the etchant. The rotation rate of the wafers fixed in the wafer basket is also not important. However, any wafer rotation should be sufficient to maintain the etchant pot sufficiently agitated and maintain a substantially uniform etchant temperature. Generally, the disturbances contribute to a uniform etchant temperature. After the etchant is heated to a suitable temperature, the etchant 88173 • 28 · 200411759 can also be cooled by conduction and / or convection caused by the contact result of the etchant with all the protective walls in the etching tank. The agitation can mix portions of the etchant having various temperatures, and therefore, a more uniform temperature can be provided at all positions where the etchant contacts the wafer surface. Generally, the rotation rate is between about 100 revolutions per minute and about 100 revolutions per minute. The preferred system has a rotation rate between about 45 revolutions per minute and about 45 revolutions per minute, and the better system is between about 5 revolutions per minute and about 30 revolutions per minute. In general, the residence time of the corrosive etchant in contact with the wafer in the etching bath (that is, the ratio of the volume of the surname bath to the flow rate of the etchant) is at least about 2 minutes. Generally speaking, the residence time of the corrosive etchant in the etching tank is between about 2 minutes and about 24 minutes, and most of them are between about 2 minutes and about 12 minutes, and even between about 2 minutes. Minutes to about 4 minutes. The amount of time that the wafer is in contact with the corrosive etchant can generally be determined based on the expected amount of debris to be removed from the wafer surface. The amount of debris to be removed is a function of the following factors: the thickness of the damaged layer; the mechanical damage to the wafer during the cutting, grinding and / or milling method steps; the defects appearing on the wafer The depth below the surface; and the expected characteristics of the final wafer. Generally, about 10 μm of material is removed from the front and back of the wafer. Generally, materials with a total thickness between about 10 μm and about 30 μm are removed from both sides of the wafer, most of which are between about 15 # 111 and about 25 μxη, and even between about 17 μm To about 23 μm of material. For the foregoing, the contact time of the wafer surface with the corrosive etchant is usually at least 5 minutes. Generally, the contact time between the wafer surface and the corrosive etchant is between about 5 minutes and about 15 minutes, and preferably between about 9 minutes and 88173 -29- 200411759 g 1U clock. From about 1 G minutes to about 10.5 minutes, until the expected amount of material is removed from the Japanese circle. By measuring the total thickness of the Xia Ying wafer before and after etching, the amount of material actually removed can be determined. When it is determined that the amount of material removed for a particular wafer =, various factors such as contact time, etchant concentration and various conditions, and the temple gate where the wafer continues to be immersed can be changed to increase or decrease the removed Alternatively, the concentration of the last name etchant can be monitored, wherein the reduction in the concentration of the hydroxide ion source in the remaining etchant is directly related to the amount of material removed from the wafer surface. Therefore, the degree of reduction of the hydroxide ion source concentration in the etchant can be monitored and used to predict the amount of material removed. Any method known to those skilled in the art can be used to measure the etchant concentration, and can be determined using the following methods, for example, by measuring the {) 1, direct conductivity of the diluted portion of the etchant , Or ionic strength injection analysis, and ion chromatography of the diluted part of the remainder. The concentration of the etchant can also be determined by performing an inductive light-plasma magnetic spectrum analysis on the diluted portion of the etchant. Those skilled in the art can understand and use other methods to determine the amount of material to be removed without departing from the scope of the present invention (such as measuring the weight of the wafer before and after etching). In addition to using immersion to contact the surface of the wafer to be etched with the etchant, it should be understood that other suitable methods can be used to contact the surface of the wafer to be etched with the corrosive etchant For example, using a spin etching method. In the spin etching method, the backside of the wafer can be placed on a spin chuck, and the etching 88173 -30-200411759 is sprayed on the opposite side while the wafer is rotated at a high speed. Although it is not very important, during the rest of the rotation, the rotation rate of the wafer is usually greater than the rotation rate during immersion | worming, and the better system is at least about 50 revolutions per minute, and the better system is at least About 150 revolutions per minute, or even at least about 25 revolutions per minute. Generally speaking, during the engraving process, the rotation rate of the wafer is between about 50 revolutions per minute and 650 revolutions per minute, and most of the wafers are between about 150 revolutions per minute and about 550 revolutions per minute. Turn between. Suitable rotary etchers include etchers sold by SEZ (Villach, Australia). During the spin rhyme, the spin chuck can be heated-heated to maintain a uniform temperature on the entire wafer surface. Regardless of how the surface of the wafer is contacted with the corrosive etchant, the etchant can be reused to continue etching additional wafers. Therefore, additional amounts of water, hydroxide ion sources, and / or salt additives must be added to the corrosive etchant in order to replace the etchant that was consumed or lost during the previous oval etch. Part. The wafer etched according to the present invention can be removed from the etchant and rinsed with deionized water. Alternatively, other rinsing solutions known in the art may be used instead of deionized water, for example, hydrogen peroxide diluent (less than 3% by weight), and ozonized deionized water. Other solutions can be used instead of deionized water. For example, SC 1, which is a standard cleaning solution consisting of ammonium hydroxide, hydrogen peroxide, and water. Wafers etched according to the present invention can exhibit advantageous surface characteristics. If compared to wafers etched with conventional corrosive etchant, it includes improved surface roughness; if compared to etching with acidic etchant, After being polished by 88173 -31-200411759, the wafer has improved flatness and fine surface shape. Compared to a wafer etched with a conventional corrosive etchant, after polishing, the wafer etched according to the present invention can further exhibit improved flatness and fine surface shape. According to a specific embodiment of the present invention, the concentration of the hydroxide ion source in the corrosive etchant exceeds 55% by weight, and the etched wafer usually exhibits an average surface coarseness of less than about 0.19 μm Ra. Preferably, the wafer inscribed according to the present invention may exhibit an average surface roughness between about 0.001 and about 019 μm Ra. Wafers etched with a corrosive etchant containing any of the above-mentioned salt additives generally exhibit an average surface roughness between about 0.14 μm to about 0.36 μm Ra, which is relatively close to acidic The desired roughness of the etched wafer (usually between about 0.09 μm to about 0.16 μm Ra), and can be easily processed (eg, using a buffing and / or polishing process) to the desired roughness. In contrast, wafers etched with a corrosive etchant that does not contain a hydroxide ion source or salt additive with a concentration of more than 55% by weight typically have a range of about 0.27 μm to about 0.35 μm The average surface roughness between Ra. Wafers etched according to the present invention generally exhibit an overall flatness of no more than 0.8 μm (that is, a universal back reference indication range or GBIR). In general, wafers etched with an etching agent containing a hydroxide ion source with a concentration of more than 55% by weight will have a GBIR between about 0.2 μm and about 0.8 μm. Generally, wafers etched using a corrosive etchant containing any of the above salt additives will have a GBIR of less than about 0.7 μm, and more preferably less than about 0.5 μm. 88173 -32-200411759 Generally speaking, wafers etched according to the present invention will typically have an improved front surface with a fine surface shape. In general, acid-etched wafers will have a fine surface shape of 2 mm X 2 mm on the front surface of at least about 7 5 nm, and a fine surface shape of 10 mm X 10 mm on the front surface of at least about 120 nm. In general, a wafer with a conventional corrosive #etcher will have a fine surface shape of 2 mm X 2 mm at the front surface of at least 20 nm, and a fine surface shape of 10 mm X 10 mm at the front surface of at least 80 nm. Wafers etched with a corrosive etchant containing a hydroxide ion source with a concentration of more than 55% by weight will usually exhibit a fine surface shape of 2 mm X 2 mm on the front surface less than about 20 nm; most of them are referred to Between about 10nm and about 20nm. Wafers engraved in this way usually also exhibit a fine surface shape of 10 mm X 10 mm on the front surface less than about 40 nm; most of them are between about 25 nm and about 40 nm. Generally, wafers engraved with a rotten silver surname containing any of the above-mentioned salt additives will exhibit a front surface 2 mm X 2 mm fine surface shape of less than about 15 nm; most of them are referred to Between about 7 nm and about 15 nm. Wafers etched in this way usually also exhibit a front surface 10 mm X 10 mm fine surface shape of less than about 35 nm; most are between about 25 nm and about 35 nm. Silicon wafers etched with an acidic or corrosive etchant can also be characterized by the smallest squared range of site flatness (site flatness, or SFQR) (SEMI Ml-1296), which is characterized by a 20 mm), the difference between the least square fitting plane based on a series of position points in a special part on the wafer surface and the actual height of the wafer surface. You can use the ADE capacity measurement method (such as the ADE 9600 flatness processing station) to determine the SFQR value of a particular 88173 -33 200411759 special site. Silicon wafers have many 20 x 20 mm sites. For example, a 200mm diameter silicon wafer will have 52 20 X 20 mm locations, so there will be 52 SFQR measurements. It can be expressed by the average value of the SFQR measurement values of the plurality of parts on the wafer surface (the average value of the part flatness, or SFQRavg) or the maximum SFQR measurement value of the wafer (the maximum part flatness, or SFQRmax). Flatness value of a particular wafer. The SFQR measurement values of all parts on the surface of the wafer can also be used to indicate the overall flatness distribution of a particular wafer, which is called the "all-bit" SFQR data of the wafer. It is also possible to indicate the number of SFQRavg, SFQRmax, and all-bit SFQR data on a preset number of wafer locations (for example, a set of 100 wafers, if each has 52 locations, it contains SFQR measurements of 5,200 locations) value). For example, you can draw SFQR measurements for all parts of a set of 100 wafers, and represent all bit data as the percentage of wafer parts (X) with flatness of parts below a certain value (Y) . It is useful to distinguish between the flatness of the entire wafer surface (ie, GBIR) and the flatness of special parts on the wafer surface (ie, SFQR), because the individual products placed on the wafer surface are designed for special purposes. The size of a body circuit or a group of integrated circuits is usually about a 20 X 20 mm site. Individual parts suitable for inclusion in integrated circuits usually require a specific minimum flatness of about 0.13 μm. Therefore, device manufacturers can use the SFQR value to determine the suitability of a wafer for each particular application. In accordance with the present invention, we have found that, in addition to improved overall flatness, compared to etching with an acidic etchant and a conventional caustic etchant 88173 -34- 200411759
晶圓，以本發明的方法所製造出來的蝕刻晶圓還會呈現出 改良的前表面部位平坦度（即具有較低的SFQR值）。一般來 說，利用含有重量百分比濃度超過55%之氫氧化物離子源的 餘刻劑來蚀刻的碎晶圓都會呈現出小於約0· 13 μιη的前表面 SFQRavg 〇較佳的係，以此方式來蚀刻的晶圓所呈現的 SFQRavg係介於約〇.〇5μπι至約0·13μπι之間，更佳的係介於 約0·05 μιη至約0.08 μιη之間。一般來說，利用含有重量百分 比濃度超過55%之氫氧化物離子源的腐蝕性蝕刻劑來蝕刻 的碎晶圓_都會呈現出小於約〇· 18 μιη的前表面SFQRmax。較 佳的係，以此方式來蝕刻的晶圓所呈現的SFQRmax係介於 約0·10 μιη至約0·18 μιη之間，更佳的係介於約0·10 μιη至約 〇· 15 μιη之間。一般來說，以此方式來蝕刻的晶圓或晶圓群 中的複數個20 X 20 mm部位中有80%的SFQR測量值係小於約 〇·〇8 μιη，而以此方式來蝕刻的晶圓或晶圓群中的複數個2〇 X 20 mm部位中則僅有50%的SFqR測量值係小於約〇 〇7 μίη。 較佳的係，以此方式來蝕刻的晶圓或晶圓群中的複數個2〇 X 20 mm部位中有80%的SFQR測量值係介於約〇.〇6 μιη至約 〇·〇8 μιη之間’更佳的係介於約〇 〇6 μιη至約〇.〇7 μιη之間。 一般來說’以酸性蚀刻劑來姓刻的晶圓上的複數個部位 中不會有約20%以上的平坦度適合用以納入一個以上的積 體電路。一般來說，以慣用的腐蝕性蝕刻劑來蝕刻的晶圓 上的複數個部位中不會有約90%以上的平坦度適合用以納 入一個以上的積體電路。雖然以慣用的腐餘性蚀刻劑來蝕 刻可以製造出極高百分率之平坦度適合用以納入複數個積 88173 -35- 200411759 體電路的邵位，不過裝置製造商卻需要具有更高之適合用 以納入複數個積體電路之百分率的晶圓。根據本發明，利 用含有重量百分比濃度低於45%之水的腐蝕性蝕刻劑來蝕 刻的矽晶圓上的複數個部位中，通常至少約有99%的平坦度 適合用以納入一個以上的積體電路。 因此，相較於以酸性蝕刻劑及慣用的腐蝕性蝕刻劑來蝕 刻的晶圓，以本發明來蝕刻的晶圓可於整個晶圓表面上呈 現出改良的（即較低的）SFQRavg值及SFQRmax值。因此，可 提供更多-適合用以納入一個以上積體電路的部位。 一般來說，利用酸性及腐蝕性蝕刻劑來蚀刻的晶圓都會 在該晶圓表面的邊緣處或其附近呈現出較低的部位平坦度 (即較高的SFQR值）。在利用酸性蝕刻劑及慣用的腐蝕性餘 刻劑來蝕刻的晶圓中所發現到的於該晶圓表面的邊緣處或 其附近的平坦度較低的現象通稱為「滾邊」。近年來，製造 商已經開始將裝置放置在靠近該晶圓表面之邊緣處，因為 欲納入裝置的晶圓表面部份的平坦度非常重要，所以，於 利用酸來蝕刻的晶圓及利用慣用的腐蝕性蝕刻劑來蝕刻的 晶圓中所發現到的滾邊問題便已成為裝置製造商的一項重 要的考量項目，因為其會降低適合納入裝置的晶圓表面的 數量。因此，除了改良整體晶圓表面的平坦度之外，吾人 特別希望能夠改良一特定晶圓在其晶圓表面邊緣處或附近 的平坦度。因此，較佳的係可以最小化該晶圓表面邊緣處 的SFQRavg值及SFQRmax值，或是最小化一含有該晶圓表 面邊緣的特殊區域的SFQRavg值及SFQRmax值。 88173 -36- 200411759 吾人已經發現，相較於以酸性蝕刻劑及慣用的腐蝕性蝕 刻劑來蝕刻的晶圓，利用包括氫氧化鈉之氫氧化物離子源 且重量百分比濃度超過55%的蝕刻劑來蝕刻的晶圓會在該 曰曰圓表面的邊緣處或其附近呈現出改良的部位平坦度（即 較低的SFQR值）。明確地說，以此方式來蝕刻一半徑為尺的 晶圓的話，其通常都會在從該晶圓之中心軸處測得之2/认 處至該晶圓周圍邊緣處之間的環狀區中呈現出不超過約 〇·13 μιη的前表面SFQRavg。一般來說，以此方式來蝕刻的 晶圓會在此環狀區中呈現出介於約〇 〇5 μιη至約〇.13 間的前表面SFQRavg。此外，以此方式來蝕刻一晶圓的話， 其通常都會在從該晶圓之中心軸處測得之2/3R處至該晶圓 周圍邊緣處之間的環狀區中呈現出不超過約〇18 μιη的前表 面SFQRmax。一般來說，以此方式來钱刻的晶圓會在此環 狀區中呈現出介於約〇·〇5 μχη至約〇 18 μπι之間的前表面 SFQRmax。因此，以此方式來蝕刻的晶圓通常都會於該晶 圓表面邊緣附近處擁有較多數量之呈現出適合用以納入一 個以上積體電路的平坦度的部位。 就旁面型怨來說’根據本發明來姓刻的晶圓不論是剛餘 刻後，或是經過一項以上進一步的作業處理（即拋光處理） 之後’其都會呈現出合宜的特徵。一般來說，根據本發明 來蝕刻的晶圓都會呈現出小於約〇 3〇 μπι Ra的平均後表面 粗链度。較佳的係’利用含有重量百分比濃度超過5 5 %之氫 氧化物離子源的腐蝕性蝕刻劑來蝕刻的晶圓所呈現出的平 均後表面粗糙度係介於約〇·15 μπι至約0·25 μπι Ra之間，更 88173 -37- 200411759 佳的係介於約0.22 μιη至約0·25 μιη Ra之間，甚至更佳地係 介於約0·22 μιη至約0.23 μπι Ra之間。一般來說，以此方式 來蝕刻的晶圓通常都會呈現出小於約3.0 μπι Rmax的最大後 表面粗糙度。較佳的係，該晶圓所呈現出的最大後表面粗 糙度係介於約2·2μπι至約2·8μιη Rmax之間，更佳的係介於約 2·2 μπι至約2.5 μπι Rmax之間，甚至更佳地係介於約2 2 μπι 至約2·3 μιη Rmax之間。 一般來說，根據本發明利用含有上述鹽類添加劑中任一 者的腐锌性蝕刻劑來蝕刻的晶圓都會呈現出小於約〇 2〇 pmRa的平均後表面粗糙度。較佳的係，以此方式來蝕刻的 晶圓所呈現出的平均後表面粗糙度係介於約〇 j 2 μιη至約 0.20 pmRa之間。一般來說，以此方式來蝕刻的晶圓通常都 會呈現出小於約2.0 μπι Rmax的最大後表面粗糙度。較佳的 係’該晶圓所呈現出的最大後表面粗縫度係介於約i 2 μιη 至約2·0 μιη Rmax之間。 一般來說，利用含有重量百分比濃度超過55%之氫氧化 物離子源的腐蝕性蝕刻劑來蝕刻的晶圓的後表面的反射係 數會小於約100個光澤單位。一般來說，於包括氫氧化神的 腐蚀性蝕刻劑情況中，該蝕刻晶圓的反射係數係介於約2〇 至約50個光澤單位之間。當該腐蝕性蝕刻劑包括氫氧化鈉 時’該姓刻晶圓的反射係數則係介於約8〇至約1 〇〇個光澤單 位之間。一般來說，在利用含有上述鹽類添加劑中任一者 的腐蝕性蝕刻劑來蝕刻的晶圓的後表面所呈現出的後表面 反射係數至少約為80個光澤單位，大部份都係介於約8〇至 88173 -38- 200411759 約160個光澤單位之間。明確地說，當該鹽類添加劑包含氟 化钟時’该独刻晶圓的反射係數通常係介於約7〇至約9〇個 光澤單位之間。當該鹽類添加劑包含碳酸鉀時，該蝕刻晶 圓的反射係數通常係介於約14〇至約16〇個光澤單位之間。 在利用含有上述鹽類添加劑中任一者之本發明的腐姓性 蝕刻劑來蝕刻的晶圓的較佳具體實施例中，該晶圓可呈現 出的平坦度小於約0·5 μιη，前表面2 mmx2 mm微細表面形 狀小於約7 nm，前表面1 〇 mm X 1 〇 mm微細表面形狀小於約 25 nm ’于均後表面粗糙度小於約〇 12 μηι Ra且最大後表面 粗糙度小於約1.2 gmRmax，以及後表面反射係數至少約為 80個光澤單位。 因此，相較於以酸來蝕刻的晶圓，本發明的腐蝕性蝕刻 劑可製造出具有改良整體平坦度（包含部位平坦度在内）的 晶圓；相較於以慣用的腐蚀性餘刻劑來姓刻的晶圓，其還 可進一步製造出具有改良整體平坦度（包含部位平坦度在 内）的晶圓。同時’相較於以酸來蚀刻的晶圓及以慣用的腐 触性蝕刻劑來蝕刻的晶圓，當根據本發明利用氫氧化鋼作 為氮氧化物離子源來敍刻晶圓時’吾人還可於該晶圓表面 的邊緣處或其附近發現到改良的平坦度。此外，相較於以 慣用的腐蝕性蝕刻劑來餘刻的晶圓，本發明的腐餘性蚀刻 劑可製造出呈現較低表面粗糙度的晶圓。 經過蝕刻之後，通常會對該晶圓進行拋光作業，用以將 該晶圓的表面粗糙度降低至半導體裝置製造商可接受的程 度（例如以10 μιη X 10 μιη視場的原子力顯微鏡技術（At〇mic 88173 -39- 200411759Wafers, etched wafers manufactured by the method of the present invention will also exhibit improved flatness of the front surface portion (ie, have a lower SFQR value). In general, broken wafers etched with an etchant containing a hydroxide ion source with a concentration of more than 55% by weight will exhibit a front surface SFQRavg of less than about 0.13 μm. In this way, The SFQRavg presented by the etched wafer is between about 0.05 μm and about 0.13 μm, and more preferably between about 0.05 μm and about 0.08 μm. Generally, broken wafers etched with a corrosive etchant containing a hydroxide ion source with a concentration of more than 55% by weight will exhibit a front surface SFQRmax of less than about 0.18 μm. The preferred system, the SFQRmax exhibited by the wafer etched in this way is between about 0.10 μιη to about 0.18 μιη, and the more preferred system is between about 0.10 μιη to about 0.15 μιη between. In general, 80% of the SFQR measurements in a plurality of 20 X 20 mm portions of a wafer or wafer group etched in this way are less than about 0.08 μm, and the crystals etched in this way Only 50% of SFqR measurements in multiple 20 × 20 mm locations in a circle or wafer group are less than about 0.07 μL. Preferably, 80% of the SFQR measurements in a plurality of 20 × 20 mm portions of a wafer or wafer group etched in this manner are between about 0.06 μm and about 0.08. Between μιη 'is more preferably between about 0.6 μιη and about 0.07 μιη. Generally, no flatness of about 20% or more in a plurality of portions on a wafer etched with an acidic etchant is suitable for incorporating more than one integrated circuit. Generally, a flatness of about 90% or more in a plurality of parts on a wafer etched with a conventional corrosive etchant is not suitable for incorporating more than one integrated circuit. Although etching with a conventional residual etchant can produce a very high percentage of flatness, which is suitable for incorporating a plurality of products, the 88173 -35- 200411759 body circuit, but the device manufacturer needs to have a higher suitable application. Wafers are included as a percentage of multiple integrated circuits. According to the present invention, at least about 99% of the flatness of a plurality of locations on a silicon wafer etched with a corrosive etchant containing water at a concentration of less than 45% by weight is generally suitable for incorporating more than one product. Body circuit. Therefore, compared with a wafer etched with an acidic etchant and a conventional corrosive etchant, the wafer etched by the present invention can exhibit an improved (ie, lower) SFQRavg value and SFQRmax value. Therefore, more-parts suitable for incorporating more than one integrated circuit can be provided. Generally, wafers etched with acidic and corrosive etchant will show lower flatness (ie higher SFQR value) at or near the edge of the wafer surface. The phenomenon of low flatness at or near the edge of the wafer surface found in a wafer etched with an acidic etchant and a conventional corrosive etchant is commonly referred to as "rolling." In recent years, manufacturers have begun to place the device near the edge of the wafer surface. Because the flatness of the wafer surface portion to be incorporated into the device is very important, the wafers etched with acid and the conventional The burring problem found in wafers etched by corrosive etchant has become an important consideration for device manufacturers because it reduces the number of wafer surfaces suitable for inclusion in the device. Therefore, in addition to improving the flatness of the overall wafer surface, I particularly want to be able to improve the flatness of a particular wafer at or near the edge of the wafer surface. Therefore, a better system can minimize the SFQRavg value and SFQRmax value at the edge of the wafer surface, or minimize the SFQRavg value and SFQRmax value of a special region containing the edge of the wafer surface. 88173 -36- 200411759 I have found that, compared to wafers etched with acidic etchant and conventional corrosive etchant, the etchant using sodium hydroxide hydroxide ion source with a concentration of more than 55% by weight is used. The wafer to be etched will show improved flatness (ie, a lower SFQR value) at or near the edge of the round surface. Specifically, when a wafer with a radius is etched in this way, it usually has a ring-shaped area between the 2 / fin measured from the center axis of the wafer and the peripheral edge of the wafer. It exhibits a front surface SFQRavg of no more than about 0.13 μm. Generally, a wafer etched in this manner will exhibit a front surface SFQRavg between about 0.05 μm and about 0.13 in this annular region. In addition, if a wafer is etched in this way, it usually shows no more than about 2 in the ring-shaped region measured from the center axis of the wafer to the periphery of the wafer. 〇18 μιη front surface SFQRmax. Generally, a wafer carved in this way will exhibit a front surface SFQRmax in this annular region between about 0.05 μχη and about 0.018 μπι. Therefore, wafers etched in this way usually have a large number of locations near the edge of the wafer surface that exhibit flatness suitable for inclusion in more than one integrated circuit. Regarding the side-type complaint, 'whether the wafer engraved according to the present invention is just after the rest, or after more than one further operation process (ie, a polishing process)', it will present a suitable characteristic. Generally, wafers etched according to the present invention will exhibit an average back surface coarse chain degree of less than about 0.30 μm Ra. A preferred system is that the average surface roughness of the wafer etched by a corrosive etchant containing a hydroxide ion source with a concentration of more than 55% by weight is between about 0.15 μm to about 0. · 25 μπι Ra, more preferably 88173 -37- 200411759 between about 0.22 μιη to about 0.25 μιη Ra, or even more preferably between about 0.22 μιη to about 0.23 μπι Ra . In general, wafers etched in this manner typically exhibit a maximum rear surface roughness of less than about 3.0 μm Rmax. Preferably, the maximum rear surface roughness exhibited by the wafer is between about 2.2 μm to about 2.8 μm Rmax, and more preferably between about 2 μm to about 2.5 μm Rmax. And even more preferably between about 2 2 μm to about 2.3 μm Rmax. Generally, wafers etched with a zinc-corrosive etchant containing any of the above-mentioned salt additives according to the present invention will exhibit an average back surface roughness of less than about 0.20 pmRa. Preferably, the average back surface roughness exhibited by the wafer etched in this manner is between about 0 j 2 μm and about 0.20 pmRa. Generally, wafers etched in this manner will typically exhibit a maximum rear surface roughness of less than about 2.0 μm Rmax. A preferred system is that the maximum back surface shirring degree exhibited by the wafer is between about i 2 μm to about 2.0 μm Rmax. Generally, the reflection coefficient of the back surface of a wafer etched with a corrosive etchant containing a hydroxide ion source with a concentration of more than 55% by weight will be less than about 100 gloss units. In general, in the case of a corrosive etchant including a hydroxide ion, the reflection coefficient of the etched wafer is between about 20 and about 50 gloss units. When the corrosive etchant includes sodium hydroxide, the reflection coefficient of the engraved wafer is between about 80 and about 100 gloss units. Generally, the rear surface reflection coefficient of a wafer etched with a corrosive etchant containing any of the above-mentioned salt additives exhibits at least about 80 gloss units, most of which are intermediate Between about 80 to 88173 -38- 200411759 between about 160 gloss units. Specifically, when the salt additive contains a fluorinated bell, the reflection coefficient of the single-engraved wafer is usually between about 70 to about 90 gloss units. When the salt-based additive contains potassium carbonate, the reflection coefficient of the etched wafer is usually between about 140 and about 160 gloss units. In a preferred embodiment of a wafer etched using the humic etchant of the present invention containing any one of the above-mentioned salt additives, the wafer may exhibit a flatness of less than about 0.5 μm. The surface 2 mmx2 mm fine surface shape is less than about 7 nm, the front surface is 10 mm X 10 mm, and the fine surface shape is less than about 25 nm. gmRmax, and the back surface reflection coefficient is at least about 80 gloss units. Therefore, compared with a wafer etched with an acid, the corrosive etchant of the present invention can produce a wafer having improved overall flatness (including flatness of a part); compared with a conventional corrosive etching The wafers carved by the agent can further be used to manufacture wafers with improved overall flatness (including flatness of parts). At the same time, 'compared to wafers etched with acid and wafers etched with conventional caustic etchants, when using the hydroxide steel as a source of nitrogen oxide ions to etch the wafer according to the present invention' Improved flatness can be found at or near the edge of the wafer surface. In addition, compared with a wafer etched with a conventional corrosive etchant, the corrosive etchant of the present invention can produce a wafer exhibiting a lower surface roughness. After etching, the wafer is usually polished to reduce the surface roughness of the wafer to a level acceptable to the semiconductor device manufacturer (for example, Atomic Force Microscopy with a field of view of 10 μm X 10 μιη (At 〇mic 88173 -39- 200411759
Force Micr〇scopy)來觀察，介於約〇 〇2 nm至約〇 5 nm之間）。 相較於以慣用的腐蝕性蝕刻劑所製造的晶圓，由本發明之 蚀刻曰曰圓所呈現出來的改良的表面特徵可以縮短拋光時 間。可以利用熟習本技術的人士已知的慣用設備與材料來 進行拋光作業。一般來說，利用本發明來蝕刻且經過拋光 作業處理的晶圓的後表面的反射係數可能高達约3〇〇個光 澤單位。一般來說，利用本發明來蝕刻且經過拋光作業處 理的晶圓的後表面的反射係數係介於約12〇個光澤單位至_ 約300個光澤單位之間，大部份係介於約ι4〇個光澤單位至 約180個光澤單位之間。於較佳的具體實施例中，可對經過 本發明蝕刻之後的晶圓進行雙面拋光作業，其中可同時對 該晶圓的前後兩面進行拋光。本技術中已知的雙面拋光法 包括於下面美國專利案號中所發現到的方法：5,1，428、 5,422,316、5,952,242、5,963,821、6,043，156、6,051，498、 6，162,730、6，189,546以及6,376,335，本文以引用的方式將 其全部揭示内容併入。該拋光作業可造成呈現出反射（即類 _ 似鏡面）外觀的晶圓。 於較佳的具體實施例中，根據本發明製造出來的晶圓於 經過拋光後，前表面SFQRavg小於約0.13 μπι，前表面 SFQRmax小於約0.18 μιη，前表面2 mm X 2 mm微細表面形狀 小於約20 nm，前表面10 mm X 10 mm微細表面形狀小於約4〇 nm。所製造出來的晶圓較佳的係還會呈現出小於約〇 25 μιη Ra的平均後表面粗縫度’小於約2·5 μιη Rmax的最大後表面 粗糙度，以及小於約180個光澤單位的後表面反射係數。 88173 -40- 200411759 於另一較佳具體實施例中，可對經過本發明蚀刻之後的 晶圓進行作業，其中可在對該晶圓的前面進行拋光處理 時，同時對該晶圓的後面進行擦光處理。可以利用與晶圓 拋光作業相同的設備與材料來進行擦光作業，不過相較於 拋光處理，實施擦光處理時僅需於該晶圓上施加較低的壓 力及/或實施較短的時間長度，因此相較於在拋光處理期間 所移除的材料數量，擦光處理可從該晶圓表面中移除的材 料數量會非常地少。一般來說，經過擦光作業的晶圓的背 面的平均_表面粗糙度可減低至小於約0.18 gmRa，而且具有 至少約為150個光澤單位的反射係數（依照ASTMD 523、ISO 2813或DIN 67530標準，入射角度為60°)。 於另一具體實施例中，可利用本發明的腐钕性蝕刻劑來 蝕刻該晶圓且同時對其進行拋光。可藉由將該腐蝕性蝕刻 劑注入於該晶圓和用以對該晶圓進行拋光的一個以上拋光 墊之間來實現本具體實施例。合宜的拋光設備包括AC 1500 P或AC 2000 P雙面拋光機，兩者皆由Peter Wolters AG (位於 德國蘭斯堡）所售，並且可以利用由Rodel (Scottsdale，美國 亞利桑那州）、或Fujikoshi (位於曰本）、或SpeedFam-IPEC (Des Plaines，美國伊利諾州）所售的H2或ΜΗ拋光墊。 拋光處理會將該晶圓的總厚度變化提高約0.1 μπι至約1.5 μπι (對慣用的容量測量裝置（例如ADE 7200或ADE 9600)來 說，目前的偵測上限約為0.01 μηι)，並且會於該晶圓表面上 沉積污染物，例如微粒物質（例如矽土拋光媒介）、外來金屬 (例如鐵、辞及铭）、以及有機化合物。舉例來說，吾人預估， 88173 -41 - 200411759 典型的拋光後之200 mm晶圓於表面上會約有1至3百萬顆顆 粒的直徑超過約0.2 μπι。外來顆粒的數量僅係一預估值，因 為經過拋光後，顆粒污染的情況非常嚴重，所以慣用的雷 射掃描計算裝置（例如Tencor (位於美國加州聖荷西）6200、Force Microscopy) to observe, between about 0.02 nm to about 0.05 nm). The improved surface characteristics exhibited by the etching circle of the present invention can shorten the polishing time compared to a wafer manufactured with a conventional corrosive etchant. Polishing operations can be performed using conventional equipment and materials known to those skilled in the art. Generally, the reflection coefficient of the rear surface of a wafer etched and polished with the present invention may be as high as about 300 light units. In general, the reflection coefficient of the rear surface of a wafer etched and polished by the present invention ranges from about 120 gloss units to about 300 gloss units, most of which are between about ι4 Between 0 gloss units and about 180 gloss units. In a preferred embodiment, a double-side polishing operation can be performed on the wafer after the etching of the present invention, wherein the front and back sides of the wafer can be polished simultaneously. The double-side polishing method known in the art includes the methods found in the following U.S. Patent Nos .: 5,1,428, 5,422,316, 5,952,242, 5,963,821, 6,043,156, 6,051,498, 6,162,730, 6, 189,546 and 6,376,335, the entire disclosures of which are incorporated herein by reference. This polishing operation can result in wafers that have a reflective (i.e., mirror-like) appearance. In a preferred embodiment, after the wafer manufactured according to the present invention is polished, the front surface has SFQRavg less than about 0.13 μm, the front surface has SFQRmax less than about 0.18 μm, and the front surface 2 mm X 2 mm fine surface shape is less than about 20 nm, front surface 10 mm X 10 mm fine surface shape is less than about 40 nm. The better system of the manufactured wafer will also exhibit an average back surface roughness of less than about 025 μιη Ra, a maximum rear surface roughness of less than about 2.5 μm Rmax, and a maximum roughness of less than about 180 gloss units. Back surface reflection coefficient. 88173 -40- 200411759 In another preferred embodiment, the wafer after the etching of the present invention can be operated, wherein when the front surface of the wafer is polished, the rear surface of the wafer can be simultaneously processed. Polishing treatment. Can use the same equipment and materials for wafer polishing operations for polishing, but compared to polishing, only a lower pressure and / or a shorter time is required to implement the polishing processing Length, so the amount of material that can be removed from the wafer surface by the buffing process is very small compared to the amount of material removed during the polishing process. In general, the average surface roughness of the back surface of a wafer after polishing can be reduced to less than about 0.18 gmRa, and it has a reflection coefficient of at least about 150 gloss units (according to ASTMD 523, ISO 2813 or DIN 67530 standards) , The incident angle is 60 °). In another embodiment, the wafer can be etched and polished simultaneously using the neodymium-corrosive etchant of the present invention. This embodiment can be implemented by injecting the corrosive etchant between the wafer and one or more polishing pads used to polish the wafer. Suitable polishing equipment include AC 1500 P or AC 2000 P double-sided polishing machines, both of which are sold by Peter Wolters AG (Ransburg, Germany) and can be used by Rodel (Scottsdale, Arizona, USA), or Fujikoshi ( Located in Japan), or H2 or MU polishing pads sold by SpeedFam-IPEC (Des Plaines, Illinois, USA). The polishing process will increase the total thickness variation of the wafer by about 0.1 μm to about 1.5 μm (for conventional capacity measurement devices such as ADE 7200 or ADE 9600, the current detection limit is about 0.01 μm), and will Contaminants, such as particulate matter (such as a silica polishing medium), foreign metals (such as iron, silicon, and inscriptions), and organic compounds are deposited on the wafer surface. For example, we estimate that 88173 -41-200411759 typical polished 200 mm wafer will have about 1 to 3 million particles on the surface with a diameter of more than about 0.2 μm. The number of foreign particles is only an estimated value, because after polishing, the particle pollution is very serious, so the conventional laser scanning computing device (such as Tencor (San Jose, California, USA) 6200,
Tencor SP1、ADE CR80或AD£ CR81)都無法精確地決定出 每個晶圓有約20,000顆微粒的數量。典型的拋光後晶圓還具 有約1 X 1〇15個金屬原子/cm2 (舉例來說，如酸滴定電感耦合 電漿質量光譖分析法所決定的），以及至少約5 χ 1〇15個有機 碳原子/cm2 (舉例來說，如氣體層析法/原子放射光譜分析法 所決定的）。 等級1的晶圓的目前規格通常必須讓被吸附至該晶圓表 面上直徑超過0·2 μπι的污染顆粒濃度不大於約〇 〇6至約〇 16 個微粒/cm2 (例如在直徑200 mm之等級晶圓的前表面 上，直徑超過約〇·2 μπι的顆粒不大於約5〇顆）；具有不超過 約1 X 101G個金屬原子/cm2 ;以及具有不超過約工χ 1〇14個有 機碳原子/cm2。所以，為達該些目標濃度，必須於進行拋 光之後對該晶圓實施清洗法。本技術中已知多種可用以降 低表面污染物濃度的清洗法，例如RC A清洗法、piranha_Rc A /目洗法、巨觀及超音波清洗法、洗滌法及酸性蚀刻方法。 為充分地清洗拋光後之矽晶圓的表面，使其實質上沒有 任何污染物（即污染程度不大於對應到等級丨之晶圓的程 度），慣用的製造方法通常會於最終拋光之後包含至少兩頊 清洗作業：#最終清洗作業之前先進行一第一後拋光清洗 作業；最後可對該晶圓進行烘乾，作4後抛光清洗作業的 88173 -42- 200411759 最後步驟。於後拋光清洗 , ,,,. Q 乍業，月間（其可能包括1〇個以上的Neither Tencor SP1, ADE CR80, or AD £ CR81) can accurately determine the number of approximately 20,000 particles per wafer. A typical polished wafer also has about 1 X 1015 metal atoms / cm2 (for example, as determined by acid titration inductively coupled plasma mass spectrometry), and at least about 5 x 1015 Organic carbon atoms / cm2 (for example, as determined by gas chromatography / atomic emission spectrometry). The current specifications of a level 1 wafer must generally be such that the concentration of contaminated particles with a diameter of more than 0.2 μm on the surface of the wafer is not greater than about 006 to about 016 particles / cm2 (for example, at a diameter of 200 mm On the front surface of a graded wafer, particles with a diameter exceeding about 0.2 μm are not larger than about 50); have not more than about 1 × 101G metal atoms / cm2; and have not more than about 10 × 14 organic Carbon atom / cm2. Therefore, to achieve these target concentrations, the wafer must be cleaned after polishing. Various cleaning methods are known in the art that can be used to reduce the concentration of surface contaminants, such as RC A cleaning method, piranha_Rc A / mesh cleaning method, macro and ultrasonic cleaning methods, washing methods, and acid etching methods. In order to sufficiently clean the surface of the polished silicon wafer so that it is substantially free of any contamination (that is, the degree of contamination is not greater than the level corresponding to the level of the wafer), the conventional manufacturing method usually includes at least Two cleaning operations: #The first cleaning operation is performed before the final cleaning operation. Finally, the wafer can be dried for 88173 -42- 200411759 as the final step of the four cleaning operations. After polishing and cleaning, ,,,. Q Zhaye, between months (which may include more than 10
少驟，例如SC_ 1的驗今凰、、太、丄 J "屬4洗步騾、氬氟酸或SC-2的酸、、主 洗步騾、去離子水沖洗告啊 之200 mm晶圓的前表面 先 直僅超過約0 ·2 μπι的顆於费善/由 可降低至⑽顆。於最m 自頂叔數I便 、、、w目洗作業期間（其可能包括另外1〇 個以上的步騾，例如S(M的 二 瞰坌屬/目冼步騾、氯氣酸或SC_2 的^目洗步驟、去離子水沖洗步驟、以及烘乾步驟），在一 已拖光《扇_晶圓的前表面上直徑超過約0.2 _的顆粒 數量則T進一步降低至约15顆以下。 本發明可由下列的範例來說明，該範例僅為說明目的， 故不應視為限制本發明範疇或實作本發明的方式。 ILM1 此範㈣述的係包括以重量百分比約為58%之氫氧化納 作為氫氧化物離子源的腐蝕性蝕刻劑的使用情形。此範例 還比較根據本範例來蝕刻的晶圓和以含有重量百分比為 5〇%<氫氧化鈉的慣用腐蝕性蝕刻劑來蝕刻的晶圓的資料。 將26.5 kg的氳氧化鈉與12〇卜重量百分比為5〇%之氫氧 化鈉溶液混合之後，便可製備出含有重量百分比約為58% 之氫氧化鈉的腐蝕性蝕刻劑。 可於容量約100 1的蝕刻槽中利用15次蚀刻作業的程序來 蚀刻360片直後為200 mm的P碎晶圓，於蚀刻期間，如上述 製備而成的腐蝕性蝕刻劑會持續地迴流。欲進行敍刻的晶 圓都已經被放置在能夠固定25片晶圓的卡匣之中，而且可 藉由將該等晶圓的卡匣置入一已沉浸在該餘刻劑之中的可 88173 -43 - 200411759 被驅動、可旋轉的晶圓籃之中，便可浸泡該等晶圓。該腐 蝕性蝕刻劑的溫度會被維持在約8(rc。於該等15次蝕刻作 業的每次作業期間，該等晶圓都會被浸泡該蝕刻劑中維持 約7分鐘至約9分鐘，該時間長度足以從每片該等晶圓的表 面中移除約23 μπι的矽。可以利用ADE“ο (Westwood，美國麻薩諸塞州）所製造的ade 95〇〇容量測量 计來進仃矽移除測量。於本範例中，可將該測量計設定在 2mm邊緣排除範圍的位置來進行測量。於該等15次蝕刻作 業的私序中，蝕刻移除速率的範圍係介於約2 W卩…分鐘至 約3·28 μπι/分鐘之間。 曰該等被蝕刻矽晶圓的表面會呈現出長寬皆約為7 μιη的小 曰θ面而利用上述的私序組來進行姓刻但是利用含有重量 百分比為50%之氫氧化鈉的慣用腐蝕性蝕刻劑來蝕刻的晶 圓則Η主現出長寬皆約為12 μιη的小晶面。可以利用吻叫似， BH3顯微鏡，於膽的放大倍率下來測量該等被㈣晶圓’ 的小晶面的尺寸。根據上述的程序組來進行蝕刻但是利用 含有重量百分比約45%之氫氧化卸的慣用腐㈣蚀刻劑來 ㈣的晶圓通常會呈現出長寬皆約為18㈣的小晶面。圖工 與圖2皆為利用上述01ympusBH3顯微鏡，於2幅的放大倍 率下來測量該等被㈣晶圓表面上之小晶面尺寸的顯微照 片’其係利用含有重量百分比約观之氫氧化納的腐姓性姓 刻劑來蝕刻該等晶圓。 圖3為於該等i 5次㈣作業中被㈣的36G片歷p+晶 圓的光澤測絲圍關係圖。如圖所示，經過㈣及拖光之 後’該等晶圓的光澤範圍介於約155個光澤單位至約⑽個 88173 -44 - 200411759 光澤單位之間。於該些範例中都係根據ASTM D 2457 D 523 ，ISO 2813或 DIN 67530,利用 BYK-Gardner，美國（Columbia， 馬里蘭州）所製造的BYK-Gardner mirror-TRI-gloss光澤計 (0-2000個光澤單位，GB-4050)來進行光澤測量。 範例2 本範例會進一步闡述包括根據範例1中所述之程序製備 而成且含有重量百分比約為58%之氫氧化鈉作為氫氧化物 離子源的腐蝕性蝕刻劑的使用情形。 0 可於15次蝕刻作業的程序中如同上面範例1所述般地來 蝕刻375片直徑為200 mm的K矽晶圓。於該等15次蝕刻作業 的程序中，蚀刻移除速率的範圍係介於約2.5 μπι/分鐘至約 3.8 μιη/分鐘之間。 圖4為該等晶圓於蝕刻前後的GBIR關係圖。於該些範例 中可以利用 ADE Semiconductor, Inc· (Westwood，美國麻薩 諸塞州）所製造的ADE 9500容量測量計來進行GBIR測量。 於本範例中，可將該容量測量計設定在3 mm邊緣排除範圍 _ 的位置來進行測量。如圖所示，該等被蚀刻的碎晶圓於蚀 刻之後會呈現出改良的整體平坦度（或GBIR)。舉例來說， 姓刻前，約有50%的晶圓的GBIR在約0.80 μπι以下；触刻後， 則約有50%的晶圓的GBIR在約0.60 μιη以下。相較之下，以 含有重量百分比約為50%之氫氧化鈉的慣用腐蝕性蝕刻劑 來蝕刻的晶圓於經過蝕刻後的平坦度和經過碾磨後的平坦 度比較起來並未有改良的情形發生（也就是在碾磨後且利 用慣用的腐蝕性蝕刻劑以上述的程序進行蝕刻之前，約有 88173 -45 - 200411759 50%的晶圓的GBIR在約0·80μπι以下，但是蚀刻後其GBIR仍 然在約0·8 μιη以下）。 圖5為該等晶圓於蝕刻前後的SFQRmax測量關係圖。於該 些範例中可以利用 ADE Semiconductor，Inc· (Westwood，美 國麻薩諸塞州）所製造的ADE 9500容量測量計，以上面針對 GBIR測量所述輿使用的方式來進行SFQRmax測量。進行 SFQRmax測量時，亦可將該容量測量計設定在3 mm邊緣排 除範圍的位置。如圖所示，於以含有重量百分比約為58% 之氫氧化鈉的腐餘性蚀刻劑來触刻的晶圓中，大部份皆呈 現出改良的前表面SFQRmax。舉例來說，蝕刻前，約有50% 的晶圓的SFQRmax在約0·14 μιη以下；蝕刻後，SFQRmax則 在約0.13 μιη以下。相較之下，以含有重量百分比約為50% 之氫氧化鈉的慣用腐蝕性蝕刻劑來蝕刻的晶圓於以上述的 程序進行蝕刻之前，約有50%的晶圓的SFQRmax在約0.14 μιη以下，蚀刻後其SFQRmax則在約0.15以下。 圖6為於該等15次蝕刻作業的程序中被蝕刻的375片晶圓 的光澤測量與平均表面粗糙度測量關係圖。於該些範例中 可以利用前 Federal Products，Inc·(現在稱為 Mahr Federal， Inc. (Providence，美國羅德島州））所製造的Federal Gage Surfanalyzer 5000(Federal Products Surface Analyzer 5000)來 進行表面粗糙度測量。如圖6所示，該等被蝕刻晶圓於經過 姓刻及掘光後呈現出約0.16 μιη Ra至約0·21 μιη Ra的平均 表面粗糖度。在進行蝕刻時，該等晶圓的平均表面粗链度 係介於約0.25至約0.32 μιη Ra之間。圖6中還顯示出，該等 88173 -46- 200411759 被蝕刻晶圓的反射係數係介於約27個光澤單位。至約45個光 澤單位之間。 範例3 本範例會進一步闡述包括根據範例1中所述之程序製備 而成且含有重量百分比約為58%之氫氧化鈉作為氫氧化物 離子源的腐蝕性蝕刻劑的使用情形。 為比較不同研磨料的效能，於進行碾磨之前，可先將該 等晶圓分成兩群：第1群含有1551片晶圓，可以利用Fujimi America，· Inc· (Wilsonville，美國奥勒崗州)所製造的 PWA 9 研磨料來進行碾磨；第2群含有100片晶圓，可以利用同樣 為 Fujimi America，Inc· (Wilsonville，美國奥勒崗州）所製造 的FO 1200研磨料來進行碾磨。 可於該等83次蝕刻作業的程序中如上面範例1所述般的 方式來蝕刻該等1651片，直徑為200 mm的P-矽晶圓（78次係 對第1群晶圓進行蝕刻，5次係對第2群晶圓進行蝕刻），每 進行一次蝕刻作業時該卡匣通常都含有20片晶圓，不過第 77次作業時，該卡匣只含有16片晶圓，而第78次作業時， 該卡匣只含有15片晶圓。如圖7所示，於該等83次蝕刻作業 的程序中，蚀刻移除速率的範圍係介於約3.2 μπι/分鐘至約 3.8 μιη/分鐘之間。 圖8為根據本範例來進行蝕刻的晶圓於碾磨後及蝕刻後 的GBIR關係圖。如圖所示，該等被蚀刻的碎晶圓於|虫刻之 後會呈現出改良的整體平坦度（或GBIR)。舉例來說，碾磨 後，但是在蝕刻前，約有50%的晶圓的GBIR在約0.85 μπι以 88173 -47- 200411759 下；姓刻後’則約有50%的晶圓的GBIR在約0.65 μιη以下。 相較之下，以含有重量百分比約為50%之氫氧化鈉的慣用腐 蝕性蝕刻劑來蝕刻的晶圓於經過蝕刻後的平坦度和經過碾 磨後的平坦度比較起來並未有改良的情形發生（也就是，於 利用慣用的腐蚀性姓刻劑來蚀刻的晶圓的情況中，當根據 上面的方法來碾磨之後，約有50%的晶圓的GBIR在約0.85 μιη以下’但是在根據上面的程序以慣用的腐餘性姓刻劑來 進行蚀刻之後，約有50%的晶圓的GBIR仍然在約0.85 μπι以 下）。- 圖9為根據本範例來進行碾磨與姓刻的第1群晶圓於2 5 X 2 5 mm部位上的SFQRmax值關係圖。可將如範例1與2所述之容 量測量計設定在2 mm邊緣排除範圍的位置來進行GBIR與 SFQRmax測量。如圖所示，該等被姓刻碎晶圓有部份會呈 現出改良的前表面SFQRmax。舉例來說，碾磨後，但是在 蚀刻前，約有50%的晶圓的SFQRmax在約0.20 μιη以下；姓 刻後，則約有50%的晶圓的SFQRmax在約0·17 μπι以下。相 較之下，根據上面的方法來碾磨且以含有重量百分比約為 50%之氫氧化鈉的慣用腐蝕性蝕刻劑依照上述的程序來蝕 刻的晶圓則約有43%的晶圓的SFQRmax在約0·17 μπι以下。 圖10、11及12皆為利用Olympus，ΒΗ3顯微鏡，於200Χ的 放大倍率下所產生的顯微照片，各圖中顯示的係於不同次 的作業中被蝕刻的第1群晶圓中的晶圓照片。圖1〇所示的係 於第23次蝕刻作業中被蝕刻的晶圓，其中可從該晶圓表面 移除21 ·1 μπι的矽，用以製造光澤約為29個光澤單位且平均 88173 -48- 200411759 表面粗縫度約為0.242 晶圓。圖u所示的係於第％ 次姓刻作業中被㈣的晶圓，其中可從該晶圓表面移除2〇 7 μιη的秒，用以製造光澤約為28個光澤單位且平均表面粗糖 度约為0.226 pinRa的晶圓。圖12所示的係於第川次兹刻作 業中被蝕刻的晶圓’其中可從該晶圓表面移除216 _的 矽，用以製造光澤約為33個光澤單位且平均表面粗糙度約 為0.244 pmRa的晶圓。該等光澤測量及粗糙度測量的方式 分別如範例1與2所述。 圖13矣一利用〇lympus，BH3顯微鏡，於2〇〇χ的放大倍率籲 下所產生的顯微照片，圖中顯示出於最後5次（79-83)蝕刻作 業期間中任一次被蝕刻的第2群晶圓中的晶圓照片。圖13所 示的係一已經被蝕刻的晶圓，其可從該晶圓表面移除174 μπι的矽，用以製造光澤約為3〇個光澤單位且平均表面粗糙 度約為0.172 μιη Ra的晶圓。該等光澤測量及粗韃度測量的 方式分別如範例1與2所述。 弟1群晶圓的平均表面粗糙度係介於約0.22 μπι Ra至約參 0·25 μπι Ra之間，而平均光澤測量則約為30個光澤單位。如 圖13所示之第2群晶圓的表面粗糙度約為0· 172 gmRa，而反 射係數則約為30個光澤單位。因此，相較於根據上面的程 序來碾磨且以含有重量百分比約為50%之氫氧化鈉的慣用 腐蝕性蝕刻劑來蝕刻的晶圓（以慣用的腐蚀性蝕刻劑來蝕 刻的晶圓所呈現出的平均表面粗糙度通常係介於約0.27 μπι Ra至約0·3 5 μιη Ra之間），該等被蚀刻的晶圓呈現出改良 的整體表面粗縫度。相較於以含有重量百分比約為50%之氫 88173 -49- 411759 氧化鈉的慣用腐蝕性蝕刻劑來蝕刻的晶圓，於該等多個蝕 刻作業的私序中，第1群與第2群晶圓的表面粗链度測量結 果於蝕刻時皆顯示出改良的表面粗糙度。這些結果還顯示 出，本發明的腐蝕性蝕刻劑可在使用各種碾磨研磨料的條 件下讓被蝕刻的晶圓具有預期的表面特徵。 範例4 本範例會進一步闡述含有重量百分比約為58%之氫氧化 鈉且根據範例1中所述之程序製備而成的腐蝕性蝕刻劑的 使用情形-。本範例還會比較以此腐蝕性蝕刻劑來蝕刻的晶 圓、以含有重量百分比約為45❶/〇之氫氧化鉀的慣用腐蝕性蝕 刻劑來敍刻的晶圓、以及根據標準的酸性蝕刻準則來蝕刻 的晶圓的資料。 可於15次蝕刻作業的程序中如同上面範例1所述般地來 餘刻285片直徑為200 mm的P+矽晶圓。於該等15次蝕刻作業 的程序中，蝕刻移除速率的範圍係介於約2·5 μπι/分鐘至約 3·8 μιη/分鐘之間。 於蚀刻之後，可以利用由peter Wolters AG (位於德國蘭斯 堡）所製造的Peter Wolters AC 1400P依照差別式雙面拋光法 來對該等晶圓進行拋光處理，其中每次可對15片進行拋光 處理。於進行該雙面拋光法期間，可從每片該等被蝕刻晶 圓的背面中移除約〇 15 μιη至約〇 2〇 μιη的矽，同時從該被蝕 刻晶圓的前面中移除約1 ·5 μπι的矽。相較於該等剛蝕刻完 之晶圓的全部位SFqr值，該等經過雙面拋光處理的晶圓呈 現出改良的全部位SFQR (每片該等已被蝕刻之晶圓上所有 88173 -50- 200411759 部位的SFQR測量值）。於該些範例中可以利用ADE Semiconductor，Inc. (Westwood，美國麻薩諸塞州）所製造的 ADE 9700容量測量計來進行全部位SFQR測量。於本範例 中，可將該容量測量計設定在2 mm邊緣排除範圍的位置來 進行全部位SFQR測量。 圖14為如上所述般利用含有重量百分比約為58%之氫氧 化鈉的本發明的腐蝕性蝕刻劑來蝕刻的晶圓於碾磨後、蝕 刻後、以及擦光後的SFQRmax值關係圖。如圖所示，姓刻 $ 後，約有_50%的晶圓的SFQRmax係在約0.12 μπι以下。圖14 還顯示出，該等擦光後的晶圓於利用本發明之氫氧化鈉腐 蝕性蝕刻劑來蝕刻後，約有50%的晶圓的SFQRmax係在約 0.10 μπι以下。 圖15為利用含有重量百分比約為45%之氫氧化鉀的標準 腐蝕性蝕刻劑來蝕刻的晶圓於碾磨後、蝕刻後、以及擦光 後的SFQRmax值關係圖。如圖所示，利用該含有重量百分 比約為45%之氫氧化鉀的標準氫氧化鉀腐蝕性蝕刻劑來蝕 _ 刻的晶圓於蝕刻後約有50%的晶圓的SFQRmax係在約0.17 μπι以下。圖15還顯示出，該等擦光後的晶圓於利用該含有 重量百分比约為45%之氫氧化鉀的標準氫氧化鉀腐蝕性蚀 刻劑來蝕刻後，約有50%的晶圓的SFQRmax係在約0.14 μπι 以下。 圖16為以如上述般製備而成之含有重量百分比約為58% 之氫氧化鋼的腐姓性姓刻劑來蚀刻的晶圓，以及以含有重 量百分比約為45%之氫氧化鉀的標準腐蝕性蝕刻劑來蝕刻 88173 -51 - 200411759 的晶圓於拋光前後的SFQRmax值關係圖。可將該容量測量 計設定在2 mm邊緣排除範圍的位置來進行SFQRmax測量。 如圖16所示，利用含有重量百分比約為58%之氫氧化納的 本發明的氫氧化納腐姓性蚀刻劑來敍刻的晶圓於抛光前約 有50%的晶圓的SFQRmax係在約0·115 μπι以下。同樣如圖16 所示，利用含有重量百分比約為45%之氫氧化鉀的標準氫氧 化鉀腐蝕性蝕刻劑來蝕刻的晶圓於拋光前約有50%的晶圓 的SFQRmax係在約0.145 μπι以下。同樣如圖16所示，利用 含有重i百分比約為58%之氫氧化鈉的本發明的氫氧化鈉 腐蝕性蝕刻劑來蝕刻的晶圓於拋光後約有50%的晶圓的 SFQRmax係在約0· 10 μπι以下。圖16還顯示出，利用含有重 量百分比約為45%之氫氧化_的標準氫氧化鉀腐钕性姓刻 劑來蝕刻的晶圓於拋光後約有50%的晶圓的SFQRmax係在 約0·11 μιη以下。 本範例中之碾磨後’蝕刻後、以及拋光後之晶圓的全部 位SFQR值係與以標準氫氧化鉀腐蝕性蝕刻劑來蝕刻的晶 圓作比較。作為比較用途的氫氧化鉀腐蝕性蝕刻劑係由重 量百分比為45%之1201的氫氧化卸溶液所組成的。可於8次 蝕刻作業的程序中根據上述範例1所述之蝕刻方法，以標準 的氫氧化鉀腐蝕性蝕刻劑來蝕刻200片直徑為200 mm的Ρ+ 矽晶圓，不過該重量百分比為45%之標準氫氧化鉀蝕刻劑的 溫度則係被維持在約9 0 °C。可根據本範例上面所述的方式 來對該等利用該重量百分比為45%之標準氫氧化鉀蝕刻劑 來餘刻的晶圓進行拋光處理。 88173 -52- 200411759 圖17為以含有重量百分比約為58%之氫氧化納的本發明 的氫氧化鈉腐蝕性蝕刻劑來蝕刻的晶圓’以及以含有重量 百分比約為45%之氫氧化钾的標準腐ϋ性蚀刻劑來姓刻的 晶圓於拋光前後的全部位SFQR值關係圖。可將該容量測量 計設定在2 mm邊緣排除範圍的位置來進行全邵位SFQR測 量。 如圖17所示，利用含有重量百分比約為58%之氫氧化鈉的 本發明的氫氧化鈉腐蝕性蝕刻劑來蝕刻的晶圓於拋光前約 有50%的/曰圓的全部位SFQR係在約0.045 μιη以下。同樣如 圖17所示，利用含有重量百分比約為45%之氫氧化鉀的標準 氫氧化鉀腐蝕性蝕刻劑來蝕刻的晶圓於拋光前約有50%的 晶圓的全部位SFQR係在約0.065 μιη以下。 圖17還顯示出，利用含有重量百分比約為58%之氫氧化鈉 的本發明的氫氧化#3腐蚀性蚀刻劑來蚀刻的晶圓於拋光後 約有50%的晶圓的全部位SFQR係在約0.05 μιη以下，而利用 含有重量百分比約為45%之氫氧化鉀的標準氫氧化鉀腐蝕 性蝕刻劑來蝕刻的晶圓於拋光後則約有50%的晶圓的全部 位SFQR係在約0.054 μιη以下。 為作進一步的比較用途，圖18顯示的係根據美國專利案 第5,340,437號中所提出的程序組，以含有氫氟酸（HF)、硝 酸（ηνο3)以及磷酸（η3ρο4)的酸性蝕刻劑來蝕刻的矽晶圓 的全部位SFQR資料關係圖，其使用的係先前由Steag AG (Donaueschegen，德國）所製造，而目前則由Santa Clara Plastics (Boise，ID)所製造的垂直蝕刻機。根據美國專利案 88173 -53 - 第5,340,437號的程序，其實蝕刻時間約為2 5分鐘，蝕刻溫 度約為3 5 C ’並且可從該晶圓表面中移除約23 μιη的碎。如 圖18所示，根據此標準的蝕刻準則來蝕刻的晶圓中，約有 50%的全部位SFQR約在〇·27 μιη以下。 因此，相較於利用含有重量百分比約為45〇/〇之氳氧化鉀 的標準氫氧化钾腐姓性鍅刻劑來姓刻的晶圓以及利用標準 酸性蚀刻準則中慣用的酸性蝕刻劑來蝕刻的晶圓，利用含 有重量百分比濃度約為58°/。之氫氧化鈉的腐蝕性蝕刻劑來 蝕刻的晶·圓會呈現出較佳的表面特徵，其特徵為全部位 SFQR測量結果。 因此，相較於上面利用慣用的氫氧化鉀腐蝕性蝕刻劑的 各種方法來蝕刻的晶圓，上面利用高濃度的氫氧化鈉腐蝕 性蝕刻劑的各種方法來蝕刻的晶圓會呈現出改良的表面特 徵，其特徵為較低的SFQRmax值及全部位SFQR值。 範例5 本範例闡述的係含有包括氟化鉀在内的鹽類添加劑的腐 蝕性蝕刻劑的使用情形。 首先’以1:1的莫耳比例’於水（70 g)中製備無水氟化_ (220 g)的溶液。將此溶液和重量百分比為45%之氫氧化卸 (300 g)水溶液混合之後，便可製備出該腐蝕性蝕刻劑。如 此所製備出來的腐蝕性蝕刻劑便含有莫耳百分比約35%的 氫氧化鉀、莫耳百分比約22%的氟化鉀、以及莫耳百分比約 4 3 %的水。 可以鐵氟龍钳固定一 25 mm X 75 mm的P+碎晶圓樣本，並 88173 -54- 200411759 且將其浸泡在根據上述方法製備而成且盛裝於一 12〇 燒杯内的腐蝕性蝕刻劑之中（約100 ml)。該蝕刻劑的溫度會 被維持在约80°c。可以利用磁攪拌棒來攪動該腐蝕性蝕刻 劑’促進水樣本與該蝕刻劑之間的接觸，用以促成更均勻 的蝕刻劑溫度。 於浸泡約8分鐘又15秒之後，便可從該晶圓樣本的表面中 移除18.8 μπι的矽，該矽樣本會被抽出該蝕刻劑之外。可以 利用 ADE Semiconductor，Inc. (Westwood，美國麻薩諸塞州） 所製造的_ADE MiCrosense 6033容量測量計來進行本範例的 矽移除測量。 孩被蝕刻的矽晶圓樣本會呈現出長寬皆約為2〇 的小 晶面，與利用不含有鹽類添加劑之腐蝕性蝕刻劑來蝕刻的 晶圓所呈現出來的大小相同。可以利用〇lympus，細顯微 鏡’於1G00X的放大倍率下來測量該等被㈣晶圓的小晶面 的尺寸。不過，利用含有鹽類添加劑之腐蝕性蝕刻劑來蝕 刻的晶81樣本的小晶面通常會近似於利用不含有鹽類添加 劑之腐姓性蚀刻劑來姓刻的晶圓所呈現出來的小晶面。圖 19為利用〇lympus，BH3顯微鏡，於1〇〇〇χ的放大倍率下所產 生的被蚀刻晶圓樣本的顯微照片’圖中顯示出於本範例中 被蝕刻的晶圓樣本的小晶面的大小與特性。 相較於利用不含有鹽類添加劑之腐純㈣劑來姓刻的 晶圓所呈現出來的小晶面(其光澤測量結果通常為介於約 90至約之間）’該晶圓樣本的光澤約糾個光澤單位。 於本範例中被蝕刻的晶圓樣本的平均表面粗糙度約為"9 88173 -55- 200411759 μιη Ra 〇 範例6 本範例闡述的係含有包括碳酸鉀在内的鹽類添加劑的腐 蝕性蝕刻劑的使用情形。 可將75.4 g的碳酸鉀、75.1 g的水、以及重量百分比為45% 之15· 1 g的氫氧化鉀水溶液混合之後，便可製備出該腐蝕性 姓刻劑。如此所製備出來的腐姓性姓刻劑便含有莫耳百分 比約11 % (重量百分比10%)的氫氧化_、莫耳百分比約6% (重量百分比45%)的碳酸鉀、以及莫耳百分比約83〇/0(重量百 分比45%)的水。 可以鐵氟龍鉗固定一 25 mm X 75 mm的P+矽晶圓樣本，並 且將其浸泡在根據上述方法製備而成且盛裝於一 12〇瓜1的 燒杯内的腐姓性蚀刻劑之中（約1 〇〇 ml)。該蚀刻劑的溫度會 被維持在約100°C。可以利用磁攪拌棒來攪動該腐蝕性蝕刻 劑’促進水樣本與該蝕刻劑之間的接觸，用以促成更均勻 的蝕刻劑溫度。 於浸泡約2分鐘之後，便可從該晶圓樣本的表面中移除 32·1 μηι的矽，該樣本會被抽出該蝕刻劑之外。可以利用上 面範例5中所述的方式來實施碎移除測量。 該被蝕刻的矽晶圓樣本會呈現出長寬皆約為2〇 μηι的小 晶面，與利用不含有鹽類添加劑之腐蝕性蝕刻劑來蝕刻的 曰曰圓所主現出來的大小相同。可以利用〇lympus，ΒΗ3顯微 鏡，於200X的放大倍率下來測量該等被蝕刻晶圓的小晶面 的尺寸。不過，利用含有鹽類添加劑之腐蝕性蝕刻劑來蝕 88173 -56 - 200411759 刻的晶圓樣本的小晶面通常會近似於利用不含有鹽類添加 劑之慣用腐蝕性蝕刻劑來蝕刻的晶圓所呈現出來的小晶 面。圖20為利用Olympus, BH3顯微鏡，於200X的放大倍率 下斤產生的被餘刻曰曰圓樣本的顯微照片’圖中顯示出於本 範例中被蚀刻的晶圓樣本的小晶面的大小與特性。 該晶圓樣本的光澤約為140個光澤單位，而該晶圓樣本的 平均表面粗糙度澤約為0.23 μιη Ra 〇 為達比較目的，可以根據上面範例1中所述的程序，以含 有重量瓦分比約為45%之氫氧化鉀但不含鹽類添加劑的慣 用腐敍性姓刻劑來蚀刻一晶圓。該姓刻劑的溫度會被維持 在約90°C。該晶圓與該蝕刻劑接觸了約7至約9分鐘之後， 便可從該晶圓的表面中移除約2〇至25 μιη的碎。可以利用上 面範例5中所述的方式來實施矽移除測量。以含有重量百分 比約為45%之氫氧化鉀但不含鹽類添加劑的腐蝕性蝕刻劑 來餘刻的晶圓呈現出的反射係數介於約9〇個至約11〇個光 澤單位，而平均表面粗糙度則約〇·3 pm Ra。相較於以不含 鹽類添加劑的腐蝕性蝕刻劑來蝕刻的晶圓，如本範例中所 述般，以含有鹽類添加劑的腐蝕性蝕刻劑來蝕刻的晶圓晶 圓樣本會呈現出改良的表面特徵。 本發明並不僅限於上述的具體實施例，並且可進行各種 修改。上面較佳具體實施例的說明僅希望讓熟習本技術的 人士能夠瞭解本發明以及其原理與實際應用情形，而且熟 習本技術的人士還可以調整本發明，使其適應於各種型式 中，以便能夠與特殊用途的規定達到最佳的配合。 88173 -57- 200411759 雖然全文中（包括下面的申請專利範圍在内）有使用到「包 括」一語及其各種衍生語，不過，應該注意的係，除非内 文必要，否則應該瞭解的係該等術語係作包含性解釋，而 非作除外解釋，而且其目的係希望能夠解釋該些術語，以 便瞭解整篇文章。 【圖式簡單說明】 圖1為一利用Olympus, BH3顯微鏡，於200χ的放大倍率下 所產生的顯微照片，圖中顯示出在根據本發明於範例i中所 述之腐铐性液態蝕刻劑系統之中進行蝕刻的p+矽晶圓的表 面。 圖2為一利用Olympus，BH3顯微鏡，於2〇〇χ的放大倍率下 所產生的顯微照片，圖中顯示出在根據本發明於範例丨中所 述之腐蚀性液態蝕刻劑系統之中進行蝕刻的p+矽晶圓的表 面0 圖3為根據本發明於範例1中所述般來進行蝕刻的36〇片 P+晶圓的光澤測量關係圖。 圖4為如範例2中所述般來進行蝕刻的p-晶圓於蝕刻前後 的整體平坦度（或GBIR值）關係圖。 圖5為如範例2中所述般來進行蝕刻的p-晶圓於飯刻前後 的最大部位平坦度的最小平方範圍（SFQRmax)值的關係圖。 圖6為如範例2中所述般來進行姓刻的p-晶圓於蚀刻後的 光澤測量與平均表面粗链度測量（μιη Ra)關係圖。 圖7為如範例3中所述般來進行姓刻的F晶圓於83次蝕刻 作業中的蝕刻速率。 88173 -58- 200411759 圖8為如範例3中所述般來進行蝕刻的p-晶圓於碾磨後及 姓刻後的整體平坦度（或（^酊尺值）關係圖。 圖9為如範例3中所述般來進行蝕刻的p_晶圓於碾磨後及 蝕刻後的SFQRmax值關係圖。 圖1〇為一利用Olympus, BH3顯微鏡，於2〇〇χ的放大倍率 下所產生的顯微照片，圖中顯示出根據本發明於範例3中所 述般來進行蝕刻的第丨群晶圓中的p-矽晶圓的表面。圖1〇所 示的晶圓係於第23次蝕刻作業中被蝕刻。 圖11為-一利用Olympus，BH3顯微鏡，於2〇〇χ的放大倍率 下所產生的顯微照片，圖中顯示出根據本發明於範例3中所 述般來進行蝕刻的第1群晶圓中的Ρ-矽晶圓的表面。圖丨“斤 示的晶圓係於第50次蝕刻作業中被蝕刻。 圖12為一利用〇lympus，ΒΗ3顯微鏡，於2〇〇χ的放大倍率 下所產生的顯微照片，圖中顯示出根據本發明於範例3中所 述般來進行蝕刻的第1群中的ρ-矽晶圓的表面。圖丨2所示的 晶圓係於第70次蝕刻作業中被蝕刻。 圖13為一利用〇lympus，BH3顯微鏡，於2〇〇χ的放大倍率 下所產生的顯微照片，圖中顯示出根據本發明於範例3中所 述般來進行蝕刻的第2群中的ρ-矽晶圓的表面。 圖14為如範例4中所述般來進行蝕刻的ρ+碎晶圓的 SFQRmax值關係圖，其係利用含有重量百分比約為58%之氫 氧化鈉的腐蝕性蝕刻劑來進行蝕刻。圖中顯示出該晶圓於 碾磨後且蝕刻前、蝕刻後、以及擦光處理後的全部位sfqr 值0 88173 59- 200411759 圖15為如範例4中所述般來進行蝕刻的P+砍晶圓的 SFQRmax值關係圖，其係利用含有重量百分比約為45%之氫 氧化鉀的腐蝕性蝕刻劑來進行蝕刻。圖中顯示出該晶圓於 碾磨後且蝕刻前、蝕刻後、以及擦光處理後的全部位SFQR 值。 圖16為如範例4中所述般來進行触刻的P+碎晶圓於拋光 前後的SFQRmax值關係圖，其係同時利用含有重量百分比 約為58%之氫氧化鈉的蝕刻劑以及含有重量百分比約為 45%之氫氳化鉀的蝕刻劑來進行蝕刻。 圖17為如範例4中所述般來進行蝕刻的P+矽晶圓於拋光 前後的全部位SFQR值關係圖，其係同時利用氫氧化鈉蝕刻 劑以及氫氧化鉀蝕刻劑來進行蝕刻。 圖W為根據如範例4中所述之美國專利案第5,340,437號 中所提出的標準酸性蝕刻準則來進行蝕刻的p+矿晶圓的全 部位SFQR值關係圖。 圖19為根據範例5來蝕刻的晶圓樣本表面的1000χ放大倍 率的顯微照片。 圖20為根據範例6來蝕刻的晶圓樣本表面的2〇〇χ放大倍 率的顯微照片。 88173 -60-Less steps, for example, SC_1 test, phoenix, cyanide, " is a 4 step step, argon fluoride or SC-2 acid, main step step, deionized water rinse, 200 mm crystal The front surface of the circle is straight and only exceeds about 0 · 2 μm. During the washing operation with the maximum number of steps from the top to the bottom (which may include more than 10 steps, such as S (M's genus / membrane step, chlorine acid or SC_2) ^ Mesh washing step, deionized water washing step, and drying step), the number of particles having a diameter of more than about 0.2 mm on the front surface of the fan_wafer is further reduced to about 15 particles or less. The invention can be illustrated by the following example, which is for illustrative purposes only and should not be considered as limiting the scope of the invention or the manner in which the invention can be implemented. ILM1 The description in this paragraph includes about 58% by weight of hydroxide Sodium is used as a source of caustic etchants for hydroxide ions. This example also compares the wafer etched according to this example with a conventional caustic etchant containing 50% by weight < sodium hydroxide After mixing 26.5 kg of ytterbium sodium oxide with a 120% by weight sodium hydroxide solution of 50% by weight, a corrosive etch containing approximately 58% by weight of sodium hydroxide can be prepared. It can be etched with a capacity of about 100 1 In the groove, a program of 15 etching operations is used to etch 360 pieces of P broken wafers with a straight length of 200 mm. During the etching, the corrosive etchant prepared as described above will continue to reflow. Wafers to be etched Have been placed in a cassette capable of holding 25 wafers, and can be driven by placing the cassettes of these wafers in a immersed 88173 -43-200411759 These wafers can be immersed in a rotatable wafer basket. The temperature of the corrosive etchant will be maintained at about 8 (rc.) During each of these 15 etching operations, the crystals The wafer is immersed in the etchant for about 7 minutes to about 9 minutes, which is long enough to remove about 23 μm of silicon from the surface of each of these wafers. ADE "ο (Westwood, Massa, USA) (Advance) (USA) to make silicon removal measurement. In this example, the meter can be set to the position of the 2mm edge exclusion range for measurement. In these 15 etchings In the private sequence of the operation, the range of the etch removal rate is between about 2 W卩 ... minutes to about 3.28 μπι / minute. The surface of these etched silicon wafers will show a small θ surface with a length and a width of about 7 μιη. However, wafers etched with a conventional corrosive etchant containing 50% by weight of sodium hydroxide will show small crystal planes with a length and a width of about 12 μm. You can use a kiss, BH3 microscope, and Measure the size of the small crystal planes of the wafers under magnification. Etching is performed according to the above-mentioned procedure group, but the crystals are etched with a conventional etch etchant containing about 45% by weight of hydroxide. A circle usually presents a small crystal plane with a length and a width of about 18 ㈣. The drawing worker and FIG. 2 are both photomicrographs of the size of the small crystal planes on the surface of the wafers under the two magnifications using the above 01ympusBH3 microscope. Etched etchants to etch such wafers. Fig. 3 is a graph showing the relationship between the measured wire circumference of the 36G film calendar p + crystal circle that was captured in these 5 times of scoring operations. As shown in the figure, after rubbing and dragging, the gloss of these wafers ranges from about 155 gloss units to about 88173 -44-200411759 gloss units. In these examples, the BYK-Gardner mirror-TRI-gloss gloss meter (0-2000 pieces) manufactured by BYK-Gardner, USA (Columbia, Maryland) is used according to ASTM D 2457 D 523, ISO 2813 or DIN 67530. Gloss Unit, GB-4050). Example 2 This example will further illustrate the use of a corrosive etchant that includes sodium hydroxide prepared in accordance with the procedure described in Example 1 and containing approximately 58% by weight of a hydroxide ion source. 0 It is possible to etch 375 K silicon wafers with a diameter of 200 mm in the procedure of 15 etching operations as described in Example 1 above. In the procedure of these 15 etching operations, the etching removal rate ranges from about 2.5 μm / minute to about 3.8 μm / minute. FIG. 4 is a GBIR relationship diagram of the wafers before and after etching. In these examples, an ADE 9500 capacity meter manufactured by ADE Semiconductor, Inc. (Westwood, Massachusetts, USA) can be used for GBIR measurements. In this example, the capacity gauge can be set to the 3 mm edge exclusion range _ for measurement. As shown in the figure, these etched broken wafers exhibit improved overall flatness (or GBIR) after being etched. For example, before the last name, about 50% of the wafers had a GBIR below about 0.80 μm; after touching, about 50% of the wafers had a GBIR below about 0.60 μm. In comparison, the flatness of a wafer etched with a conventional corrosive etchant containing about 50% by weight of sodium hydroxide after etching has not been improved compared to the flatness after milling. The situation occurred (that is, after milling and before etching with a conventional corrosive etchant using the above-mentioned procedure, about 88173 -45-200411759 50% of the wafers had a GBIR below about 0.80 μm, but after the etching GBIR is still below about 0.8 μm). FIG. 5 is a measurement relationship diagram of SFQRmax of the wafers before and after etching. In these examples, an ADE 9500 capacity meter manufactured by ADE Semiconductor, Inc. (Westwood, Massachusetts, U.S.A.) can be used to perform SFQRmax measurements in the manner described above for GBIR measurements. When measuring SFQRmax, the capacity gauge can also be set to the position of the 3 mm edge exclusion range. As shown in the figure, most of the wafers etched with a caustic etchant containing about 58% by weight of sodium hydroxide showed an improved front surface SFQRmax. For example, before etching, about 50% of the wafers have an SFQRmax below about 0.14 μm; after etching, the SFQRmax is below about 0.13 μm. In comparison, wafers etched with a conventional corrosive etchant containing about 50% by weight of sodium hydroxide. Before being etched by the above procedure, about 50% of the wafers had an SFQRmax of about 0.14 μm. Hereinafter, the SFQRmax after etching is about 0.15 or less. Fig. 6 is a graph showing the relationship between the gloss measurement and the average surface roughness measurement of the 375 wafers etched in the procedure of these 15 etching operations. In these examples, the surface roughness can be performed using the Federal Gage Surfanalyzer 5000 (Federal Products Surface Analyzer 5000) manufactured by the former Federal Products, Inc. (now known as Mahr Federal, Inc. (Providence, Rhode Island, USA)). Degree measurement. As shown in FIG. 6, the etched wafers exhibited an average surface coarseness of about 0.16 μm Ra to about 0.21 μm Ra after being engraved and excavated. During the etching, the average surface rough chain degree of these wafers is between about 0.25 and about 0.32 μm Ra. It is also shown in FIG. 6 that the reflection coefficient of these 88173 -46- 200411759 etched wafers is between about 27 gloss units. To about 45 luster units. Example 3 This example further illustrates the use of a corrosive etchant including sodium hydroxide prepared as a hydroxide ion source prepared in accordance with the procedure described in Example 1 and containing approximately 58% by weight. In order to compare the performance of different abrasives, the wafers can be divided into two groups before milling. The first group contains 1551 wafers. Fujimi America, Inc. (Wilsonville, Oregon, USA) ) Manufactured by PWA 9 abrasives; the second group contains 100 wafers and can be milled using FO 1200 abrasives also manufactured by Fujimi America, Inc. (Wilsonville, Oregon, USA). mill. The 1651 P-silicon wafers with a diameter of 200 mm can be etched in the procedure of the 83 etching operations as described in Example 1 above (the first group of wafers is etched 78 times, The second group of wafers is etched 5 times.) The cassette usually contains 20 wafers for each etching operation, but at the 77th operation, the cassette contains only 16 wafers. In this operation, the cassette contains only 15 wafers. As shown in FIG. 7, in the procedure of the 83 etching operations, the range of the etching removal rate is between about 3.2 μm / minute and about 3.8 μm / minute. FIG. 8 is a GBIR relationship diagram of a wafer etched according to this example after milling and after etching. As shown in the figure, these etched broken wafers show improved overall flatness (or GBIR) after the worm etch. For example, after milling, but before etching, about 50% of the wafers have a GBIR of about 0.85 μm to 88173 -47- 200411759; after the last name, about 50% of the wafers have a GBIR of about 0.65 μιη or less. In comparison, the flatness of a wafer etched with a conventional corrosive etchant containing about 50% by weight of sodium hydroxide after etching has not been improved compared to the flatness after milling. It happened (that is, in the case of a wafer etched with a conventional corrosive etching agent, after milling according to the above method, about 50% of the wafers had a GBIR below about 0.85 μιη ', but After the etching with the conventional surviving etchant according to the above procedure, the GBIR of about 50% of the wafers is still below 0.85 μm). -Figure 9 is a graph showing the relationship between the SFQRmax value of the first group of wafers that are milled and engraved according to this example at a location of 2 5 X 2 5 mm. The GBIR and SFQRmax measurements can be performed by setting the capacity meter as described in Examples 1 and 2 at the position of the 2 mm edge exclusion range. As shown in the figure, some of these chipped wafers will show an improved front surface SFQRmax. For example, after milling, but before etching, about 50% of the wafers have an SFQRmax below about 0.20 μm; after the last name, about 50% of the wafers have an SFQRmax below about 0.17 μm. In contrast, wafers milled according to the above method and etched with a conventional corrosive etchant containing about 50% by weight of sodium hydroxide in accordance with the above procedure have an SFQRmax of about 43% of the wafers Below about 0 · 17 μm. Figures 10, 11 and 12 are photomicrographs generated at 200 × magnification using an Olympus, Β3 microscope. The crystals in the first group of wafers shown in each figure are etched in different operations. Circle photo. The wafer shown in Figure 10 is etched in the 23rd etching operation, in which 21.1 μm of silicon can be removed from the surface of the wafer to produce a gloss of about 29 gloss units and an average of 88173- 48- 200411759 Surface roughness is about 0.242 wafers. Figure u shows the wafer that was stabbed in the% th last name engraving operation, in which 207 μm seconds can be removed from the surface of the wafer to produce a gloss of about 28 gloss units and an average surface coarse sugar. Wafers with a degree of about 0.226 pinRa. The wafer shown in FIG. 12 is etched during the etch process. The silicon of 216 mm can be removed from the wafer surface to produce a gloss of about 33 gloss units and an average surface roughness of about The wafer is 0.244 pmRa. These gloss measurement and roughness measurement methods are described in Examples 1 and 2, respectively. Figure 13: A photomicrograph generated using an Olympus, BH3 microscope at a magnification of 200 ×. The figure shows the photoetched during any of the last 5 (79-83) etching operations. Photographs of wafers in the second group of wafers. The wafer shown in FIG. 13 is an etched wafer, which can remove 174 μm of silicon from the surface of the wafer to produce a gloss of about 30 gloss units and an average surface roughness of about 0.172 μm Ra. Wafer. These gloss measurements and roughness measurements are described in Examples 1 and 2, respectively. The average surface roughness of the group 1 wafer is between about 0.22 μπι Ra and about 0.25 μπι Ra, and the average gloss measurement is about 30 gloss units. As shown in FIG. 13, the surface roughness of the second group of wafers is about 0.172 gmRa, and the reflection coefficient is about 30 gloss units. Therefore, compared to wafers milled according to the above procedure and etched with a conventional caustic etchant containing about 50% by weight of sodium hydroxide (wafers etched with a conventional caustic etchant) The average surface roughness exhibited is usually between about 0.27 μm Ra to about 0.35 μm Ra), and the etched wafers show an improved overall surface roughness. Compared to wafers etched with a conventional corrosive etchant containing about 50% by weight of hydrogen 88173 -49- 411759 sodium oxide, in the private sequence of these multiple etching operations, group 1 and group 2 The results of the measurement of the surface rough chain degree of the group wafers all showed improved surface roughness during etching. These results also show that the corrosive etchant of the present invention can give the etched wafer the desired surface characteristics under the conditions of using various grinding abrasives. Example 4 This example further illustrates the use of a corrosive etchant containing approximately 58% by weight of sodium hydroxide and prepared according to the procedure described in Example 1.- This example also compares wafers etched with this corrosive etchant, wafers etched with a conventional corrosive etchant containing potassium hydroxide in an amount of about 45 ❶ / 0, and standard acidic etching guidelines. To etch the wafer information. In the procedure of 15 etching operations, as described in Example 1 above, 285 P + silicon wafers with a diameter of 200 mm can be etched. In the procedure of these 15 etching operations, the range of the etching removal rate is between about 2.5 μm / minute and about 3.8 μm / minute. After etching, these wafers can be polished using Peter Wolters AC 1400P manufactured by peter Wolters AG (Lansburg, Germany) according to the differential double-side polishing method, of which 15 wafers can be polished at a time deal with. During the double-side polishing method, about 0.15 μm to about 020 μm of silicon can be removed from the back surface of each of the etched wafers, and about 0.15 μm can be removed from the front surface of the etched wafers. 1.5 μm of silicon. Compared to the all-bit SFqr value of these newly etched wafers, the double-sided polished wafers exhibit improved all-bit SFQR (all 88173 -50 on each of these etched wafers) -200411759 SFQR measurement). In these examples, an ADE 9700 capacity meter manufactured by ADE Semiconductor, Inc. (Westwood, Massachusetts, USA) can be used to perform all-bit SFQR measurements. In this example, the capacity gauge can be set to the position of the 2 mm edge exclusion range to perform all-bit SFQR measurement. Fig. 14 is a graph showing the relationship between the SFQRmax values of a wafer etched after milling, etching, and buffing using the corrosive etchant of the present invention containing about 58% by weight of sodium hydroxide as described above. As shown in the figure, after the last name $, the SFQRmax of about _50% of the wafers is below about 0.12 μm. FIG. 14 also shows that after the polished wafers are etched with the sodium hydroxide corrosive etchant of the present invention, the SFQRmax of about 50% of the wafers is below about 0.10 μm. Fig. 15 is a graph showing the relationship between the SFQRmax values of a wafer etched using a standard corrosive etchant containing about 45% by weight of potassium hydroxide after milling, etching, and polishing. As shown in the figure, the standard potassium hydroxide corrosive etchant containing about 45% by weight of potassium hydroxide is used to etch the wafer. The SFQRmax of about 50% of the wafers after etching is about 0.17. μπι or less. FIG. 15 also shows that after the polished wafers were etched with the standard potassium hydroxide corrosive etchant containing about 45% by weight of potassium hydroxide, the SFQRmax of about 50% of the wafers was etched. It is below about 0.14 μm. FIG. 16 is a wafer etched with a humic name etching agent containing about 58% by weight of a hydroxide steel prepared as described above, and a standard containing about 45% by weight of potassium hydroxide Corrosive etchant to etch the SFQRmax value of 88173 -51-200411759 wafer before and after polishing. This capacity gauge can be set to the position of the 2 mm edge exclusion range for SFQRmax measurement. As shown in FIG. 16, the SFQRmax of about 50% of the wafers etched by using the sodium hydroxide etching etchant of the present invention containing about 58% by weight of sodium hydroxide before polishing is about SFQRmax. Below about 0.115 μm. Also shown in FIG. 16, a wafer etched with a standard potassium hydroxide corrosive etchant containing about 45% by weight of potassium hydroxide. About 50% of the wafers before polishing have an SFQRmax of about 0.145 μm. the following. As shown in FIG. 16, the wafer etched by using the sodium hydroxide corrosive etchant of the present invention containing sodium hydroxide with a weight percentage of about 58% is about 50% of the SFQRmax of the wafer after polishing. Below about 0 · 10 μπι. FIG. 16 also shows that about 50% of the wafers etched with a standard potassium hydroxide neodymium-based etchant containing about 45% by weight of hydroxide are SFQRmax of about 0 after polishing. · 11 μm or less. The SFQR values of the post-milled and after-etched and polished wafers in this example are compared with the wafers etched with a standard potassium hydroxide corrosive etchant. The potassium hydroxide corrosive etchant used for comparison is composed of 1201 hydroxide dehydration solution with a weight percentage of 45%. It is possible to etch 200 P + silicon wafers with a diameter of 200 mm using a standard potassium hydroxide corrosive etchant according to the etching method described in Example 1 in the procedure of 8 etching operations, but the weight percentage is 45 The temperature of the standard potassium hydroxide etchant is maintained at about 90 ° C. Polishing of these wafers using the standard potassium hydroxide etchant with a weight percentage of 45% can be performed in the manner described above in this example. 88173 -52- 200411759 FIG. 17 is a wafer etched with the sodium hydroxide corrosive etchant of the present invention containing sodium hydroxide of about 58% by weight, and potassium hydroxide containing about 45% by weight. The SFQR value of all etched wafers before and after polishing with the standard corrosive etchant. This capacity meter can be set to the position of the 2 mm edge exclusion range for full-shaft SFQR measurement. As shown in FIG. 17, the wafer etched by using the sodium hydroxide corrosive etchant of the present invention containing about 58% by weight of sodium hydroxide has about 50% of a full-circle SFQR system before polishing. Below about 0.045 μm. Also as shown in FIG. 17, a wafer etched with a standard potassium hydroxide corrosive etchant containing about 45% by weight of potassium hydroxide is about 50% of all wafers before polishing. 0.065 μιη or less. FIG. 17 also shows that the wafer etched with the hydroxide # 3 corrosive etchant of the present invention containing about 58% by weight of sodium hydroxide has about 50% of all SFQR systems of the wafer after polishing. Below about 0.05 μιη, and a wafer etched with a standard potassium hydroxide corrosive etchant containing about 45% by weight of potassium hydroxide, after polishing, about 50% of all wafers have SFQR at Below about 0.054 μm. For further comparison, FIG. 18 shows an etching process using an acidic etchant containing hydrofluoric acid (HF), nitric acid (ηνο3), and phosphoric acid (η3ρο4) according to the program group proposed in US Patent No. 5,340,437. A full-bit SFQR data diagram of a silicon wafer using a vertical etcher previously manufactured by Steag AG (Donaueschegen, Germany) and currently manufactured by Santa Clara Plastics (Boise, ID). According to the procedure of U.S. Patent No. 88173-53-No. 5,340,437, in fact, the etching time is about 25 minutes, the etching temperature is about 3 5 C ′, and about 23 μm of debris can be removed from the surface of the wafer. As shown in FIG. 18, about 50% of all bits of the wafer etched according to this standard etching guideline have an SFQR of about 0.27 μm or less. Therefore, compared to the use of standard potassium hydroxide sacrificial etchants containing about 40% by weight of potassium osmium oxide to etch wafers and etching using conventional acid etchants used in standard acid etching guidelines The wafers used contained a concentration of about 58 ° / wt. The crystals and circles etched by the corrosive etchant of sodium hydroxide will show better surface characteristics, which are characterized by all-bit SFQR measurement results. Therefore, compared to wafers etched by various methods using conventional potassium hydroxide corrosive etchant, wafers etched by various methods using high concentration sodium hydroxide corrosive etchant will show improved performance. Surface features are characterized by lower SFQRmax values and all-bit SFQR values. Example 5 This example illustrates the use of a corrosive etchant containing a salt additive including potassium fluoride. First, a solution of anhydrous fluorinated (220 g) was prepared 'in a molar ratio of 1: 1' in water (70 g). The corrosive etchant can be prepared by mixing this solution with a 45% by weight aqueous solution of hydroxide (300 g). The corrosive etchant thus prepared contains potassium hydroxide with a mole ratio of about 35%, potassium fluoride with a mole ratio of about 22%, and water with a mole ratio of about 43%. A 25 mm x 75 mm P + chip wafer sample can be fixed with Teflon forceps, and 88173 -54- 200411759 can be immersed in the corrosive etchant prepared in accordance with the above method and contained in a 120 beaker. Medium (about 100 ml). The temperature of the etchant is maintained at about 80 ° C. A magnetic stir bar can be used to agitate the corrosive etchant ' to promote contact between the water sample and the etchant to promote a more uniform etchant temperature. After soaking for about 8 minutes and 15 seconds, 18.8 μm of silicon can be removed from the surface of the wafer sample, and the silicon sample is drawn out of the etchant. The _ADE MiCrosense 6033 capacity meter manufactured by ADE Semiconductor, Inc. (Westwood, Massachusetts, USA) can be used for the silicon removal measurement of this example. Samples of silicon wafers that are etched will show a small crystal plane with a length and width of about 20, which is the same size as a wafer etched with a corrosive etchant that does not contain salt additives. The size of the small crystal planes of these wafers can be measured using Olympus, a fine microscope 'at a magnification of 1G00X. However, the small crystal plane of the crystal 81 sample etched with a corrosive etchant containing salt additives is usually similar to the small crystals of a wafer etched with a corrosive etchant without salt additives. surface. FIG. 19 is a photomicrograph of an etched wafer sample produced at a magnification of 1000 × using an Olympus, BH3 microscope. The figure shows the small crystals of the etched wafer sample in this example. Face size and characteristics. Compared to the small crystal face (the gloss measurement result is usually between about 90 to about) of a wafer engraved with a rot pure tincture without salt additives, the gloss of the wafer sample Approximately one gloss unit. The average surface roughness of the wafer sample etched in this example is about " 9 88173 -55- 200411759 μιη Ra 〇 Example 6 This example illustrates a corrosive etchant containing a salt additive including potassium carbonate. Use cases. The corrosive surname can be prepared by mixing 75.4 g of potassium carbonate, 75.1 g of water, and 15.1 g of potassium hydroxide aqueous solution with a weight percentage of 45%. The humorous caster prepared in this way contains about 11% (10% by weight) of Moore's hydroxide, about 6% (45% by weight) of Potassium carbonate, and a percentage of Moore. About 83/0 (45% by weight) water. A 25 mm x 75 mm sample of P + silicon wafer can be fixed with Teflon forceps and immersed in the etch etchant prepared according to the above method and contained in a beaker of 120 melons ( (About 100 ml). The temperature of the etchant is maintained at about 100 ° C. A magnetic stir bar can be used to agitate the corrosive etchant ' to promote contact between the water sample and the etchant to promote a more uniform etchant temperature. After soaking for about 2 minutes, 32 · 1 μηι of silicon can be removed from the surface of the wafer sample, and the sample is drawn out of the etchant. Fragment removal measurements can be performed in the manner described in Example 5 above. The sample of the etched silicon wafer will show a small crystal plane with a length and a width of about 20 μm, which is the same size as that of a circle that is etched with a corrosive etchant containing no salt additives. The size of the small crystal planes of these etched wafers can be measured using a microscope of Olympus, Beta 3 at 200X magnification. However, the use of a corrosive etchant containing a salt additive to etch 88173 -56-200411759 wafer facets will generally approximate the facet of a wafer etched with a conventional corrosive etchant that does not contain a salt additive. The small crystal plane presented. Fig. 20 is a photomicrograph of a round sample produced by an Olympus, BH3 microscope at 200X magnification. The figure shows the size of the small crystal plane of the wafer sample etched in this example. With characteristics. The gloss of the wafer sample is about 140 gloss units, and the average surface roughness of the wafer sample is about 0.23 μιη Ra. For comparison purposes, the weight watts can be included according to the procedure described in Example 1 above. Etching a wafer with a conventionally etched nickname of about 45% potassium hydroxide but no salt additives. The temperature of the last name is maintained at about 90 ° C. After the wafer is in contact with the etchant for about 7 to about 9 minutes, fragments of about 20 to 25 μm can be removed from the surface of the wafer. The silicon removal measurement can be performed in the manner described in Example 5 above. A wafer with a caustic etchant containing about 45% by weight of potassium hydroxide but no salt additives exhibits a reflection coefficient between about 90 and about 110 gloss units, and the average The surface roughness is about 0.3 pm Ra. Compared to wafers etched with a corrosive etchant that does not contain salt additives, as described in this example, wafer wafer samples etched with a corrosive etchant that contains salt additives will show improvements Surface features. The present invention is not limited to the specific embodiments described above, and various modifications are possible. The above description of the preferred embodiments only hopes that those skilled in the art can understand the present invention, its principles and practical application situations, and those skilled in the art can also adjust the present invention to adapt it to various types, so as to be able to To achieve the best coordination with special purpose regulations. 88173 -57- 200411759 Although the term "including" and its various derivatives are used throughout the text (including the scope of patent applications below), it should be noted that unless the text is necessary, it should be understood Such terms are to be interpreted inclusively, not to exclude them, and they are intended to explain these terms in order to understand the entire article. [Brief description of the figure] FIG. 1 is a photomicrograph generated at 200 × magnification using an Olympus, BH3 microscope, showing the embolic liquid etchant described in Example i according to the present invention. Surface of etched p + silicon wafer in the system. FIG. 2 is a photomicrograph generated at 200 × magnification using an Olympus, BH3 microscope, which is shown in a corrosive liquid etchant system described in Example 丨 according to the present invention. Surface 0 of the etched p + silicon wafer FIG. 3 is a gloss measurement relationship diagram of 36+ P + wafers which are etched as described in Example 1 of the present invention. Fig. 4 is a graph showing the overall flatness (or GBIR value) of a p-wafer etched as described in Example 2 before and after the etching. Fig. 5 is a graph showing the relationship between the minimum squared range (SFQRmax) value of the maximum flatness of a p-wafer before and after a meal is etched as described in Example 2. FIG. 6 is a graph showing the relationship between the gloss measurement and the average surface rough chain degree measurement (μιη Ra) of the p-wafer after etching as described in Example 2. FIG. FIG. 7 is an etch rate of the F wafer which was engraved as described in Example 3 in 83 etching operations. 88173 -58- 200411759 Figure 8 shows the relationship between the overall flatness (or (^ 酊)) of the p-wafer after milling and after engraving as described in Example 3. Figure 9 The relationship between the SFQRmax values of the p_ wafer after milling and after etching as described in Example 3. Figure 10 is a result of using an Olympus, BH3 microscope at a magnification of 200 ×. A photomicrograph showing the surface of a p-silicon wafer in a group of wafers etched as described in Example 3 according to the present invention. The wafer shown in FIG. It is etched during the etching operation. FIG. 11 is a photomicrograph generated by using an Olympus, BH3 microscope at a magnification of 200 ×, and the figure shows that the etching is performed as described in Example 3 of the present invention. The surface of the P-silicon wafer in the first group of wafers. Figure 丨 "The wafer shown is etched in the 50th etching operation. Figure 12 is a microscope using Olympus, β3 microscope, at 200 The photomicrograph produced at a magnification of χ shows an etching process as described in Example 3 of the present invention. The surface of the ρ-silicon wafer in group 1. The wafer shown in Fig. 2 was etched in the 70th etching operation. Fig. 13 is a magnification of 200 × using an Olympus and BH3 microscope. The photomicrograph generated below shows the surface of the p-silicon wafer in the second group which is etched as described in Example 3 according to the present invention. FIG. 14 is the same as described in Example 4. A graph of the SFQRmax value of the etched ρ + broken wafer, which is etched using a corrosive etchant containing about 58% by weight of sodium hydroxide. The figure shows that the wafer is etched after milling The sfqr value of all bits before, after etching, and after buffing treatment is 0 88173 59- 200411759. Figure 15 is a SFQRmax value relationship diagram of a P + diced wafer that is etched as described in Example 4. It uses the weight percentage Approximately 45% of potassium hydroxide is used to etch. The figure shows the SFQR value of the wafer after milling and before etching, after etching, and after polishing. Figure 16 shows such as SFQRmax value of P + broken wafer before and after polishing as described in Example 4 Relation diagram, which uses both an etchant containing approximately 58% by weight of sodium hydroxide and an etchant containing approximately 45% by weight of potassium hydride. FIG. 17 is as described in Example 4. The SFQR value of all the P + silicon wafers before and after polishing is generally etched, which uses both sodium hydroxide etchant and potassium hydroxide etchant to etch at the same time. A graph showing the SFQR value of all bits of a p + ore wafer etched using standard acidic etching guidelines proposed in US Patent No. 5,340,437. FIG. 19 is a 1000 × magnification photomicrograph of the surface of a wafer sample etched according to Example 5. FIG. FIG. 20 is a 200 × magnification photomicrograph of the surface of a wafer sample etched according to Example 6. FIG. 88173 -60-