529147 A7 _____B7______五、發明說明（） 發明領域： 本發明係有關於一種半導體元件之金屬熔絲結構’特 別是有關於一種具弱連結（Weak Link)之金屬熔絲結構的 製造方法。 發明背景： 經濟部智慧財產局員工消費合作社印製 積體電路元件通常包括有可熔導 記憶體或是邏輯電路重新配線。例如 讀記憶體（Electrically Erasable and Only Memories，EEPROM)、動態隨機 Random Access Memories, DRAM)以 體（Static Random Access Memories， 導體記憶體中，一旦發現缺陷的記憶 冗餘技術（Redundancy Technology)藉 陷記憶胞相連的熔絲，再選擇式地以 以增加半導體記憶胞的良率及降低生 輯電路亦可藉由切斷熔絲而進行電路 如，一般在邏輯晶片中最初係製作大 最後製程階段時再依照客戶需求切斷 之炫絲以形成具意欲邏輯功能之晶片 線或熔絲，以用於對 ，在可抹除可程式唯 P r 〇 g r a m m a b 1 e Read 存取記憶體（Dynamic 及靜態隨機存取記憶 SR AM)諸如此類的半 胞時，可使用修補或 由雷射熔斷與此等缺 備用的記憶胞替代， 產成本。同樣地，邏 修補或重新配線。例 量的連線邏輯閘，在 不需要的電路連線間 (請先閱讀背面之注意事項再填寫本頁) t 訂_ 線 529147 A7 _B7_ 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 典型地，用於製作半導體元件之金屬熔絲的材質係包 括鋁、銅或鎢。由於金屬熔絲通常係與頂層的金屬導線同 時形成，而且半導體元件在檢測及接合時需要足夠的機械 強度，因此頂層金屬層的厚度通常很厚，例如約為1 2000 埃。當熔絲形成於此種厚的頂層金屬層時，熔斷熔絲所需 之雷射能量及時間係相對地增加。假如熔斷的時間不夠， 則熔絲吸收的能量不足便易導致不理想的熔斷良率，若延 長熔斷的時間，則會降低製程效率、增加能量成本及容易 損壞溶絲周圍的其他元件，不符合經濟效益。因此，亟需 有一種新的熔絲結構以解決上述問題。 發明目的及概述： 有鑒於上述發明背景中，習用半導體元件之金屬熔絲 形成於最頂層金屬層時所遭遇之若干問題，例如金屬層厚 度太厚、耗費雷射能量及不易達成理想熔斷良率等缺點， 加上考慮金屬熔絲的性質及後續製程之需求，本發明係提 出一種新的金屬熔絲結構及其形成方法，以解決上述問題。 經濟部智慧財產局員工消費合作社印製 法 方 造 製 的 絲 熔 屬 金 之 結 il 弱 具 種一 供 提 為 的 目 之 明 發 本 另 之 明 發 本 絲 熔 金 之 結 連 具 種一 供 提 為 的 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7_ 五、發明說明（） 可降低金屬熔絲熔斷所需之雷射能量以及提高熔斷良率， 且不需添加額外的製程步驟。 (請先閱讀背面之注意事項再填寫本頁) 根據以上所述之目的，本發明中具弱連結之金屬熔絲 的製造方法係包括以下步驟：形成一第一介電層於一半導 體基材上，其中第一介電層中係埋設有導線層，接著形成 一第二介電層於第一介電層上，然後形成至少一孔洞於第 二介電層中，最後形成一具低階梯覆蓋（Step Coverage)的 金屬層於第二介電層上。其中，形成於第二介電層之側壁 上的金屬層係具低階梯覆蓋，因而形成有利於雷射熔斷之 弱連結。 經濟部智慧財產局員工消費合作社印製 根據以上所述之目的，本發明之金屬熔絲結構係至少 包括有一半導體基材；一第一介電層形於半導體基材上， 第一介電層内已埋設有導線層，第一介電層與導線層之上 表面係經平坦化處理以使第一介電層與導線層的上表面共 平面；一第二介電層形於第一介電層上，第二介電層中係 形成至少一溝渠；一阻障層於第二介電層及至少一溝渠 上；一金屬層於阻障層上；以及一保護層於金屬層上，其 中形成於溝渠側壁上之金屬層係具低階梯覆蓋而形成熔絲 之弱連結部分，有利於雷射熔斷。 根據本發明所述的具弱連結之金屬熔絲的製造方法並 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7_ 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 不需要增加任何額外的曝光、蝕刻及沉積等製程。根據本 發明之第一至三實施例，藉由在熔絲蝕刻期間於介電層中 形成至少一溝渠，以及形成一金屬層於溝渠上，便可形成 具弱連結之金屬熔絲。由於溝渠的階梯覆蓋性不佳，因此 形成於溝渠側壁上之金屬層具有較薄厚度而成為炫絲的弱 連結部分。弱連結的數量係視實際需求可為一或多個，且 弱連結的長度及深度可依溝渠的斜率及寬度而定。根據本 發明之第四實施例，可在積體電路佈局時於熔絲結構中形 成一窄寬度的頸部，此頸部係成為整個熔絲結構中的弱連 結部分。 相較於習知的金屬熔絲結構，根據本發明之方法所形 成的金屬熔絲結構係具至少一弱連結部分，較易由雷射熔 斷，可增加熔斷良率及減少製程成本。 圖式簡單說明： 本發明的較佳實施例將於往後之說明文字中輔以下列 圖形做更詳細的闡述，其中： 經濟部智慧財產局員工消費合作社印製 第1圖為習知金屬熔絲結構的剖面示意圖； 第2 a〜C圖為本發明之一較佳實施例之金屬熔絲結構 的製程剖面示意圖； 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7 五、發明說明（） 第2 d圖為第2 c圖中之金屬熔絲的弱連結部分之局部 放大圖； (請先閱讀背面之注意事項再填冩本頁) 第3圖為本發明另一較佳實施例之金屬熔絲結構的剖 面示意圖； 第 4 a圖為本發明又一較佳實施例之金屬熔絲結構的 剖面示意圖； 第4b圖為第4a圖中之金屬熔絲的弱連結部分之局部 放大圖； 第5圖為包含依照本發明再一較佳實施例之金屬熔絲 結構的局部積體電路佈局圖。 請注意隨附的圖式僅係說明本發明之較佳實施例，本 發明之範圍並不侷限於此等隨附圖式，本發明仍適用於其 它等效之實施例。 圖號對照說明： 經濟部智慧財產局員工消費合作社印製 基材 第一介電層 導線層 第二介電層 介層洞 插塞 阻障層 10、 110、 210、 310 20 、 120 、 220 、 320 11 、 122 、 222 、 322 30、 130 ' 230、 330 32 、 132 36 、 136 40 、 140 、 240 、 340 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7 五、發明說明（） 50 、 150 、 250 、 350 金屬熔絲層 13 1 光阻層 134 、 234 、 334 溝渠 152 、 252 、 352 弱連結 410 熔絲 412 頸部 414A、414B 熔絲端部 420A 、 420B 金屬接觸窗插塞 430A 、 430B 導線 440 熔絲窗 450 保護環 發明詳細說明： (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 鑒於上述習知熔絲結構在由雷射熔斷時所遭遇之若干 問題，本發明係提供一種半導體元件之金屬熔絲結構，以 在使用雷射對半導體元件進行修補或冗餘技術時，可容易 及有效地熔斷熔絲，其中本發明之金屬熔絲結構的特徵在 於具有低階梯覆蓋的弱連結部分。 第1圖為習知金屬熔絲結構的剖面示意圖。如第1圖 所示，半導體基材10上係形成第一介電層20，其中第一 介電層2 0内係埋設有多重導線層2 2，例如可包括複數層 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7_ 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 内金屬介電層（Inter-Metal Dielectric)、形成於每一内金屬 介電層上之金屬内連線，以及形成於内金屬介電層中之金 屬插塞用以耦接每一内金屬介電層上下方之金屬内連線。 在完成第一介電層20之導線層22的埋設之後，通常使用 化學機械研磨法（Chemical Mechanical Polishing, CMP)對 第一介電層2 0與導線層2 2的上表面進行平坦化處理，以 使第一介電層20與導線層22的上表面共平面。接著形成 第二介電層 30於第一介電層 20之上，再利用微影 (Photolithography)及乾I虫刻製程於第二介電層 30中形成 介層洞（Via Hole)32。然後，形成阻障層40於第二介電層 30 上以防止後續形成之金屬層的擴散及電致遷移 (Electromigration)，再形成金屬層50於阻障層40之上， 最後對金屬層 5 0進行微影及乾蝕刻製程以定義出熔絲之 輪靡。傳統地，炼絲通常與頂層的金屬層同時形成，由於 半導體元件在檢測及接合時需要足夠的機械強度，因此頂 層金屬層的厚度通常很厚，例如約為1 2000埃。當熔絲形 成於如此厚的頂層金屬層時，需要耗費較高的雷射能量或 較長的熔斷時間才能將熔絲熔斷，且不易達成理想的熔斷 良率。因此，本發明係提出一種可提高熔斷良率的熔絲結 構及其製造方法。 第2 a〜c圖係繪示根據本發明第一較佳實施例之金屬 熔絲結構的製程剖面示意圖。如第2 a圖所示，半導體基材 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 110上係形成第一介電層120,其中第一介電層120中係埋 設有導線層1 22，導線層1 22可包括例如複數層内金屬介 電層、形成於每一内金屬介電層上之金屬内連線，以及形 成於内金屬介電層中之插塞用以耦接每一内金屬介電層之 上下方金屬内連線。較佳地，形成第一介電層1 2 0的方法 可使用化學氣相沉積法。第一介電層1 2 0的材質可包括氧 化矽或其它適合之介電材質，而導線層1 22的材質可包括 銅、鋁或鎢。在本實施例中，第一介電層12 0的材質為氧 化矽而導線層的材質為銅。在完成第一介電層120與導線 層1 22的製作後，可採用化學機械研磨法對第一介電層1 20 與導線層1 2 2的上表面進行平坦化處理以使其等之上表面 共平面。 經濟部智慧財產局員工消費合作社印製 接著，沉積第二介電層1 3 0於第一介電層1 2 0上，然 後形成一光阻層131於第二介電層130上以定義出介層洞 1 3 2及熔絲溝渠1 3 4，再經由乾蝕刻製程以轉移光阻圖案於 第二介電層1 3 0上，最後移除光阻層1 3 1。較佳地，第二 介電層130的材質可包括氧化矽（SiOx)或其它適合的介電 材料，乾蝕刻製程可使用包括有CF4、C4F8、CHF3、N2 ; Ar、C 0之混合氣體進行。在本實施例中，形成於第二介電 層1 3 0之介層洞1 3 2係分別對準並暴露出第一介電層中的 導線層1 2 2，而熔絲溝渠1 3 4係形成於此二介層洞1 3 2之 間。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 B7 五、發明說明（） (請先閱讀背面之主意事項再填寫本頁) 參閱第2b圖，在去除光阻層1 3 1之後，接著形成一阻 障層1 40於第二介電層1 3 0、介層洞1 3 2及熔絲溝渠1 3 4 的上表面及側壁表面，以防止後續形成之金屬層的擴散及 電致遷移。阻障層的材質可包括氮化鈦、氮化钽、钽或鎢 化鈦等。接著，形成一金屬層1 5 0於阻障層1 4 0上，如第 2 c圖所示。較佳地，金屬層 1 5 0的形成方式可使用濺鍍 (Sputtering)方式，滅鑛金屬層150的材質可包括铭或銅， 介層洞1 3 2係由濺鍍的金屬填塞形成金屬插塞1 3 6，而與 第一介電層120中之導線層122電氣耦接。由於濺鍍對溝 渠結構的階梯覆蓋性不佳，大多數的濺鍍金屬係沉積在晶 片表面，而在溝渠兩側沉積較小的金屬厚度。因此，在本 實施例中，形成於溝渠側壁1 5 2之金屬層係具有較低的階 梯覆蓋（如第2d圖所示），成為整個熔絲結構中的弱連結部 分，因而有利於雷射熔斷。金屬熔絲結構之弱連結的數量 可視需求而為一或多個，且弱連結的長度及厚度可依熔絲 溝渠的斜率、寬度及實際需求而定。 經濟部智慧財產局員工消費合作社印製 第3圖係繪示本發明之第二較佳實施例之金屬熔絲結 構的剖面示意圖。本實施例之金屬熔絲結構的形成方式係 大致與第2 a〜c圖所示者相似，惟在本實施例中係使用不同 的光阻圖案（未圖示），以使第二介電層2 3 0經乾蝕刻製程 後形成不同剖面輪廓的溝渠。如第3圖所示，第二介電層 10 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 經濟部智慧財產局員工消費合作社印製 A7 B7 五、發明說明（） 23 0中係形成一溝渠234,此溝渠234係暴露出第一介電層 220中兩相鄰的導線層222，在本實施例之第二介電層中係 忽略介層洞。同樣地，依序形成一阻障層240及一金屬層 2 5 0於第二介電層2 3 0及熔絲溝渠2 3 4上。本實施例之結 構係較傳統熔絲（如第1圖所示）的結構簡單，因無需介層 洞，金屬炫絲係直接與下層的導線相連。除此之外，由於 形成於熔絲溝渠 2 3 4之側壁2 5 2上的金屬層具低階梯覆 蓋，致使形成於熔絲溝渠側壁2 5 2之金屬層的厚度較薄， 因而成為此熔絲結構的弱連結部分，有利於雷射熔斷。 第 4a圖係繪示本發明之第三較佳實施例之金屬熔絲 結構的剖面示意圖。本實施例之金屬熔絲結構的形成方式 係大致與第2 a〜c圖所示者相似，惟本實施例中所使用之光 阻圖案係為第2a〜c圖之反相（Reverse Tone)光阻圖案，因 此所形成之熔絲形狀係與第 2 c圖的熔絲形狀相反。如第 4a圖所示，第二介電層3 3 0在經微影及乾蝕刻製程後係形 成二溝渠3 34,此二溝渠3 3 4係分別暴露出第一介電層320 中兩相鄰的導線層3 2 2。接著，依序形成一阻障層3 4 0及 一金屬層350於第二介電層330及熔絲溝渠334上。同樣 地，熔絲溝渠3 3 4之側壁3 5 2具有低階梯覆蓋，故形成於 溝渠側壁3 5 2上的金屬層厚度較薄（如第4b圖所示），因此 成為此熔絲結構的弱連結部分而有利於雷射熔斷。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) .擔 訂*. 529147 A7 B7 五、發明說明（ 一般在進行雷射熔斷之過程中，假如熔絲的寬度太大 枯，熔斷熔絲所需的雷射能量較大且時間較長；相反地， 如果溶絲的寬度太窄或太薄小時，由於溶絲本身所能吸收 的雷射熱能相應地減少以及熔絲所吸收的熱能易被周圍之 介電層排散掉，故不易達到熔絲熔斷所需的溫度。因此， 本發明係提出一種有利於雷射熔斷之熔絲結構。第5圖係 繪不包含有根據本發明第四實施例之熔絲結構的積體電路 佈局圖。如第5圖所示，在一半導體基材上已完成部分的 積體電路，其中金屬熔絲4 1 〇係形成於兩相鄰的金屬接觸 窗插塞420A ' 420B之間，雷射光束係經由熔絲窗44〇(如 虛線所示）將溶絲410熔斷。通常，在金屬熔絲41〇周圍可 形成保護環4 5 0以防止金屬熔絲遭受濕氣侵蝕。金屬熔絲 4 1 0係包括有一熔絲頸部4丨2以及兩分別連接接觸窗插塞 420A、42 0B的熔絲端部414A、414B，熔絲頸部412係具 有較窄之寬度。二金屬接觸窗插塞420A、420B分別藉由 導線430A、430B與其它共同的半導體元件相連。相較於 習知具一致寬度的熔絲結構，本實施例中具較窄寬度頸部 (請先閱讀背面之注意事項再填寫本頁) ，雄 訂： --線- 經濟部智慧財產局員工消費合作社印製 容時視而學矽 較及係格化化 ， 量量規強氮 分能數欲增如 部射的意漿例 結雷部依電 G 連之頸可以層 弱需之度會1 一 所構長常介 成絲結及通層 形熔絲度，二 上斷熔寬後至 構熔。的之一 結少率部作積 絲減良頸製沉 溶可斷且的式 體故熔，絲方 整，的個熔D) 在斷想多屬 V 係炫理或金 E 構射到一成(P 結雷達為完積 絲由而可在沉 溶藉，求。相 之易間需定氣 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 529147 A7 _B7_ 五、發明說明（） 層或氧化矽層）於金屬熔絲上以作為保護層（Passivation)。 此介電層可再進行一道微影及乾蝕刻製程以裸露出元件的 銲墊（Β ο n d i n g P a d)，用來進行元件的測試與構裝之用。 如以上所述，根據本發明上述方法所形成之金屬熔絲 結構係自然形成有利於雷射熔斷之弱連結部分，並不需要 再對熔絲進行額外的微影及蝕刻等製程。考慮到半導體元 件在檢測及接合時之機械強度需求，根據本發明上述方法 形成的金屬熔絲結構係可與頂層金屬層同時形成，不需要 縮減金屬層厚度便可形成有利於雷射熔斷的弱連結部分， 提高雷射熔斷操作之良率。 雖然本發明已以較佳實施例揭露如上，熟悉此項技術 人士應瞭解以上所述僅為本發明之較佳實施例而已，並非 用以限定本發明，在不脫離本發明之精神及範圍内所完成 之等效改變或修飾，均應包含在下述之申請專利範圍内。 (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）529147 A7 _____B7______ V. Description of the invention () Field of the invention: The present invention relates to a metal fuse structure of a semiconductor element, particularly to a method for manufacturing a metal fuse structure with a weak link (Weak Link). Background of the Invention: Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economics, integrated circuit components usually include fusible memory or rewiring of logic circuits. For example, in reading memory (Electrically Erasable and Only Memories (EEPROM), dynamic random access access memories (DRAM), and static random access memories (Conductive memory), once the defect is found, memory redundancy technology (Redundancy Technology) traps memory Fuses connected to the cell, and then selectively to increase the yield of the semiconductor memory cell and reduce the generator circuit. Circuits can also be performed by cutting the fuse. For example, when the logic chip is initially manufactured in the final process stage According to the customer's needs, the dazzling wire is cut to form a chip line or fuse with the intended logic function. It can be used for pairing. The programmable memory only can be erased and programmable. P r grammab 1 e Read access memory (Dynamic and static random When accessing memory SR AM) and other half cells, it can be repaired or replaced by laser fuses and these unavailable memory cells. The cost is the same. Similarly, logic repair or rewiring. Routine wiring logic gates, Between unnecessary circuit connections (please read the precautions on the back before filling this page) t Order _ line 529147 A7 _B7_ V. Description of the invention () (Please read the precautions on the back before filling out this page) Typically, the material used to make semiconductor fuses is aluminum, copper or tungsten. Since metal fuses are usually formed at the same time as the top metal wires Moreover, semiconductor devices need sufficient mechanical strength when testing and bonding, so the thickness of the top metal layer is usually very thick, for example, about 1 2000 angstroms. When a fuse is formed in such a thick top metal layer, the fuse is blown. The required laser energy and time are relatively increased. If the fuse time is not enough, the insufficient energy absorbed by the fuse will easily lead to unsatisfactory fuse yield. If the fuse time is extended, the process efficiency will be reduced and the energy cost will be increased. And other components around the fuse are easy to damage, which is not economically beneficial. Therefore, a new fuse structure is urgently needed to solve the above problems. Purpose and summary of the invention: In view of the above background of the invention, metal fuses of conventional semiconductor components are used. Some problems encountered when forming the topmost metal layer, such as the metal layer is too thick, it consumes laser energy, and it is difficult to reach Disadvantages such as ideal fuse yield, and considering the nature of metal fuses and the needs of subsequent processes, the present invention proposes a new metal fuse structure and its forming method to solve the above problems. Consumer Cooperatives, Intellectual Property Bureau, Ministry of Economic Affairs The silk fuse made by the printing method is a knot of gold il Weak species with one purpose for the purpose of the present issue The other is issued for the purpose of the silk melt gold and the type is provided for the purpose Standard (CNS) A4 specification (210 X 297 mm) 529147 A7 B7_ V. Description of the invention () It can reduce the laser energy required for the metal fuse to blow and increase the fuse yield without adding additional process steps. (Please read the precautions on the back before filling this page.) According to the purpose described above, the method for manufacturing a metal fuse with a weak connection in the present invention includes the following steps: forming a first dielectric layer on a semiconductor substrate Above, a conductive layer is buried in the first dielectric layer, then a second dielectric layer is formed on the first dielectric layer, then at least one hole is formed in the second dielectric layer, and finally a low step is formed. A step covering metal layer is on the second dielectric layer. Among them, the metal layer formed on the side wall of the second dielectric layer is covered with a low step, thereby forming a weak connection which is favorable for laser fusing. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs According to the above-mentioned purpose, the metal fuse structure of the present invention includes at least a semiconductor substrate; a first dielectric layer is formed on the semiconductor substrate, and the first dielectric layer A wire layer has been embedded therein. The first dielectric layer and the upper surface of the wire layer are planarized to make the first dielectric layer and the upper surface of the wire layer coplanar. A second dielectric layer is formed on the first dielectric layer. On the electrical layer, at least one trench is formed in the second dielectric layer; a barrier layer is on the second dielectric layer and at least one trench; a metal layer is on the barrier layer; and a protective layer is on the metal layer, The metal layer formed on the side wall of the trench is covered with a low step to form a weak connection part of the fuse, which is beneficial to laser fusing. According to the method for manufacturing a metal fuse with a weak connection according to the present invention and the paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) 529147 A7 B7_ V. Description of the invention () (Please read the back first Note: Please fill in this page again) No need to add any additional exposure, etching and deposition processes. According to the first to third embodiments of the present invention, a metal fuse having a weak connection can be formed by forming at least one trench in the dielectric layer and forming a metal layer on the trench during fuse etching. Because the step coverage of the trench is not good, the metal layer formed on the side wall of the trench has a thin thickness and becomes a weak connection part of the dazzling wire. The number of weak links can be one or more according to actual needs, and the length and depth of the weak links can be determined by the slope and width of the trench. According to the fourth embodiment of the present invention, a narrow neck portion can be formed in the fuse structure when the integrated circuit is laid out, and this neck portion becomes a weakly connected portion in the entire fuse structure. Compared with the conventional metal fuse structure, the metal fuse structure formed by the method of the present invention has at least one weak connection portion, which is easier to be fused by laser, which can increase the fuse yield and reduce the manufacturing cost. Brief description of the drawings: The preferred embodiment of the present invention will be explained in more detail in the following explanatory texts with the following figures, where: Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, the first figure is the conventional metal melting Sectional schematic diagram of the wire structure; Figures 2a ~ C are schematic cross-sectional schematic diagrams of the manufacturing process of a metal fuse structure according to a preferred embodiment of the present invention; This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 529147 A7 B7 V. Description of the invention (2) Figure d is a partial enlarged view of the weak connection part of the metal fuse in Figure 2c; (Please read the precautions on the back before filling this page) Figure 3 is A schematic cross-sectional view of a metal fuse structure according to another preferred embodiment of the present invention; FIG. 4a is a schematic cross-sectional view of a metal fuse structure according to another preferred embodiment of the present invention; FIG. A partially enlarged view of a weakly connected portion of a wire; FIG. 5 is a partial integrated circuit layout diagram including a metal fuse structure according to yet another preferred embodiment of the present invention. Please note that the accompanying drawings are only illustrative of the preferred embodiments of the present invention, and the scope of the present invention is not limited to these accompanying drawings, and the present invention is still applicable to other equivalent embodiments. Comparative illustration of drawing numbers: Printed substrates of the first consumer layer of the Intellectual Property Bureau of the Ministry of Economic Affairs, Consumer Cooperatives, the first dielectric layer, the wire layer, the second dielectric layer, the via plug barrier layer 10, 110, 210, 310 20, 120, 220, 320 11 、 122 、 222 、 322 30 、 130 ′ 230 、 330 32 、 132 36 、 136 40 、 140 、 240 、 340 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) 529147 A7 B7 V. Description of the invention (50) 150, 250, 350 metal fuse layer 13 1 photoresist layer 134, 234, 334 trench 152, 252, 352 weak connection 410 fuse 412 neck 414A, 414B fuse end 420A, 420B metal contact window plug 430A, 430B wire 440 fuse window 450 protection ring invention detailed description: (Please read the precautions on the back before filling this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs in view of the above-mentioned conventional fuse The structure encounters several problems when the laser is fused. The present invention provides a metal fuse structure of a semiconductor element to repair or redundantly use the laser to repair the semiconductor element. During the operation, the fuse can be easily and effectively blown. The metal fuse structure of the present invention is characterized by a weakly connected portion having a low step coverage. FIG. 1 is a schematic cross-sectional view of a conventional metal fuse structure. As shown in FIG. 1, a first dielectric layer 20 is formed on a semiconductor substrate 10, and a plurality of conductive wire layers 22 are embedded in the first dielectric layer 20. For example, a plurality of layers may be included. Standard (CNS) A4 specification (210 X 297 mm) 529147 A7 B7_ V. Description of the invention () (Please read the precautions on the back before filling this page) The Intellectual Property Bureau, Ministry of Economic Affairs, Employee Consumer Cooperatives printed the inner metal dielectric layer (Inter-Metal Dielectric), metal interconnects formed on each inner metal dielectric layer, and metal plugs formed in the inner metal dielectric layer to couple the upper and lower portions of each inner metal dielectric layer Metal interconnects. After the wiring layer 22 of the first dielectric layer 20 is buried, the upper surfaces of the first dielectric layer 20 and the wiring layer 22 are usually planarized by using a chemical mechanical polishing (CMP) method. The first dielectric layer 20 and the upper surface of the wiring layer 22 are coplanar. Next, a second dielectric layer 30 is formed on the first dielectric layer 20, and then a photolithography and a dry etching process are used to form a via hole 32 in the second dielectric layer 30. Then, a barrier layer 40 is formed on the second dielectric layer 30 to prevent diffusion and electromigration of the subsequently formed metal layer, and then a metal layer 50 is formed on the barrier layer 40. Finally, the metal layer 5 0 Lithography and dry etching processes are performed to define the success of the fuse. Traditionally, the skein is usually formed at the same time as the top metal layer. Since semiconductor devices require sufficient mechanical strength during inspection and bonding, the thickness of the top metal layer is usually very thick, for example, about 12,000 angstroms. When the fuse is formed in such a thick top metal layer, it takes a higher laser energy or a longer fuse time to fuse the fuse, and it is not easy to achieve the ideal fuse yield. Therefore, the present invention proposes a fuse structure and a method for manufacturing the same which can improve the melting yield. Figures 2a to c are schematic cross-sectional views showing the manufacturing process of the metal fuse structure according to the first preferred embodiment of the present invention. As shown in Figure 2a, the paper size of the semiconductor substrate applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 529147 A7 B7 V. Description of the invention () (Please read the precautions on the back before filling in this The first dielectric layer 120 is formed on the system 110. The first dielectric layer 120 is embedded with a conductive layer 1 22, and the conductive layer 1 22 may include, for example, a plurality of inner metal dielectric layers formed on each inner metal. Metal interconnects on the dielectric layer and plugs formed in the inner metal dielectric layer are used to couple the metal interconnects above and below each inner metal dielectric layer. Preferably, the method of forming the first dielectric layer 120 can use a chemical vapor deposition method. The material of the first dielectric layer 120 may include silicon oxide or other suitable dielectric materials, and the material of the conductive layer 12 may include copper, aluminum, or tungsten. In this embodiment, the material of the first dielectric layer 120 is silicon oxide and the material of the wire layer is copper. After the fabrication of the first dielectric layer 120 and the wire layer 1 22 is completed, the upper surfaces of the first dielectric layer 120 and the wire layer 1 2 2 may be planarized by using a chemical mechanical polishing method to make the upper layers The surfaces are coplanar. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Next, a second dielectric layer 130 is deposited on the first dielectric layer 120, and then a photoresist layer 131 is formed on the second dielectric layer 130 to define The interlayer holes 1 3 2 and the fuse trenches 1 3 4 are transferred to the second dielectric layer 130 by a dry etching process, and the photoresist layer 1 31 is finally removed. Preferably, the material of the second dielectric layer 130 may include silicon oxide (SiOx) or other suitable dielectric materials. The dry etching process may be performed using a mixed gas including CF4, C4F8, CHF3, N2; Ar, C0 . In this embodiment, the interlayer holes 1 3 2 formed in the second dielectric layer 130 are aligned and exposed respectively to the wiring layer 1 2 2 in the first dielectric layer, and the fuse trench 1 3 4 The system is formed between the two interlayer holes 1 3 2. This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 529147 A7 B7 V. Description of invention () (Please read the idea on the back before filling this page) Please refer to Figure 2b to remove the photoresist After layer 1 31, a barrier layer 1 40 is then formed on the upper surface and the side wall surface of the second dielectric layer 130, the via 132 and the fuse trench 1 34 to prevent subsequent metal formation. Layer diffusion and electromigration. The material of the barrier layer may include titanium nitride, tantalum nitride, tantalum, or titanium tungsten. Next, a metal layer 150 is formed on the barrier layer 140, as shown in FIG. 2c. Preferably, the forming method of the metal layer 150 can be a sputtering method, and the material of the demineralizing metal layer 150 can include a copper or copper, and the via hole 1 3 2 is formed by filling the metal plug with the sputtered metal. The plug 1 36 is electrically coupled to the wiring layer 122 in the first dielectric layer 120. Due to the poor step coverage of the trench structure by sputtering, most of the sputtered metal is deposited on the wafer surface, while smaller metal thicknesses are deposited on both sides of the trench. Therefore, in this embodiment, the metal layer formed on the side wall of the trench 1 52 has a lower step coverage (as shown in FIG. 2d), which becomes a weak connection part in the entire fuse structure, which is conducive to laser Fuse. The number of weak links in the metal fuse structure can be one or more according to requirements, and the length and thickness of the weak links can depend on the slope, width and actual requirements of the fuse trench. Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs. Figure 3 is a schematic cross-sectional view showing a metal fuse structure according to a second preferred embodiment of the present invention. The formation method of the metal fuse structure in this embodiment is substantially similar to that shown in Figures 2a to 2c, but in this embodiment, a different photoresist pattern (not shown) is used to make the second dielectric Layers 2 to 30 form trenches with different cross-sectional profiles after a dry etching process. As shown in Figure 3, the paper size of the second dielectric layer 10 paper is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 529147 A7 B7 printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A trench 234 is formed in 230, and the trench 234 exposes two adjacent wire layers 222 in the first dielectric layer 220. In the second dielectric layer of this embodiment, the via holes are ignored. Similarly, a barrier layer 240 and a metal layer 250 are sequentially formed on the second dielectric layer 230 and the fuse trench 234. The structure of this embodiment is simpler than that of a traditional fuse (as shown in Fig. 1). Since no intervening hole is required, the metal wire is directly connected to the underlying wire. In addition, because the metal layer formed on the side wall 2 5 2 of the fuse trench 2 3 4 has a low step coverage, the thickness of the metal layer formed on the side wall 2 5 2 of the fuse trench is thin, and thus becomes the melting point. The weak connection part of the wire structure is conducive to laser fusing. Fig. 4a is a schematic cross-sectional view showing a metal fuse structure according to a third preferred embodiment of the present invention. The formation method of the metal fuse structure in this embodiment is roughly similar to that shown in Figs. 2a ~ c, except that the photoresist pattern used in this embodiment is the reverse Tone of Figs. 2a ~ c. Photoresist pattern, so the fuse shape formed is opposite to the fuse shape in Figure 2c. As shown in FIG. 4a, the second dielectric layer 3 3 0 forms a second trench 3 34 after the lithography and dry etching processes. The two trenches 3 3 4 respectively expose two phases in the first dielectric layer 320. The adjacent wire layer 3 2 2. Next, a barrier layer 3 40 and a metal layer 350 are sequentially formed on the second dielectric layer 330 and the fuse trench 334. Similarly, the side wall 3 5 2 of the fuse trench 3 3 4 has a low step coverage, so the thickness of the metal layer formed on the side wall 3 5 2 of the trench is thin (as shown in FIG. 4b), so it becomes the fuse structure. The weak connection part is good for laser fusing. This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling out this page). Contract *. 529147 A7 B7 V. Description of invention (generally laser In the process of fusing, if the width of the fuse is too dry, the laser energy required to blow the fuse is large and takes a long time; on the contrary, if the width of the fuse is too narrow or too thin, The laser thermal energy that can be absorbed is reduced accordingly and the thermal energy absorbed by the fuse is easily dissipated by the surrounding dielectric layer, so it is not easy to reach the temperature required for the fuse to fuse. Therefore, the present invention proposes a method that is beneficial to laser fuse Fig. 5 is a circuit diagram of an integrated circuit that does not include the fuse structure according to the fourth embodiment of the present invention. As shown in Fig. 5, the integrated circuit is completed on a semiconductor substrate. A circuit in which a metal fuse 4 1 0 is formed between two adjacent metal contact window plugs 420A ′ 420B, and a laser beam fuses the fuse 410 through a fuse window 44 0 (shown as a dotted line). Usually , Can be formed around the metal fuse 41〇 Guard ring 4 5 0 to prevent the metal fuse from being attacked by moisture. The metal fuse 4 1 0 includes a fuse neck 4 2 and two fuse ends 414A, respectively connected to the contact window plugs 420A, 42 0B, 414B, the fuse neck 412 has a narrower width. The two metal contact window plugs 420A and 420B are connected to other common semiconductor components by wires 430A and 430B respectively. Compared with the conventional fuse structure with a uniform width In this embodiment, the neck has a narrower width (please read the precautions on the back before filling this page), and it is written as follows:-Line-When comparing the printing of silicon with the Intellectual Property Bureau of the Ministry of Economic Affairs, the Consumer Cooperative Society considers the silicon as compared to Systematization, Gauges, Strong Nitrogen Energy, Number of Spaghetti Cases That Want to Be Radiated, Lightning Department, Department of Electricity, and G. The neck can be weakly needed. Layer-shaped fuse degree, after the upper fuse is wide and the structure is melted. One of the knots is made as a wire to reduce the good neck, the system is soluble and breakable, and the fuse is melted. I think that most of them belong to the V series dazzle theory or the golden E structure shot to 10% (the P-junction radar can be borrowed in Shen Rong for the completion of the silk, and it is easy to find. This sheet to be fixed gas applies China National Standard Scale (CNS) A4 size (210 X 297 mm) 529147 A7 _B7_ V. invention is described in () layer or a silicon oxide layer) on the metal to fuse the protective layer (Passivation). This dielectric layer can be subjected to a photolithography and dry etching process to expose the component pads (B o n d i n P Pa d), which is used for component testing and assembly. As described above, the metal fuse structure formed according to the above method of the present invention naturally forms a weak connection portion which is favorable for laser fusing, and does not need to perform additional lithography and etching processes on the fuse. Considering the mechanical strength requirements of semiconductor devices during detection and bonding, the metal fuse structure formed according to the above method of the present invention can be formed at the same time as the top metal layer, without the need to reduce the thickness of the metal layer to form a weak laser conducive to laser fuse. The connection part improves the yield of laser fusing operation. Although the present invention has been disclosed as above with preferred embodiments, those skilled in the art should understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention, without departing from the spirit and scope of the present invention. All equivalent changes or modifications should be included in the scope of patent application described below. (Please read the precautions on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs This paper is in accordance with China National Standard (CNS) A4 (210 X 297 mm)