1242806 五、發明說明（1) 一、 【發明所屬之技術領域】 本發明係有關於一種移除光阻的方法，特別是關於一 種在金屬層I虫刻後之移除光阻的方法。 二、 【先前技術】 現今於半導體製程中，金屬層材質種類隨著製程趨向 奈米階段而日新月異，其製程更是隨之改變，而本文以不 影響本發明實施情況下，就現今最常見之鋁材為金屬層的 製程來作為本發明之先前技術之介紹。 鋁具有低電阻、易於沉積及蝕刻等優點而廣為半導體 製程上所採用。在先進積體電路中，由於元件的密度受限 於導線所佔據之面積，加上金屬層的非等向性蝕刻可使得 金屬導線間的間距縮小，藉以增加導線之接線能力，因此 鋁的非等向性蝕刻蝕刻在積體電路製程中是一個非常重要 的步驟。 在現今製程中，因為尺寸縮小，使得蝕刻圖形高的高 寬比（A s p e c t R a t i 〇 )增加，使得钱刻製程中的反應物無法 排出而形成金屬殘存物，再加上光阻的厚度相對增加，將 使得蝕刻更加困難，例如0. 2 5// m寬的鋁線，厚度大約 0 . 5// m，而光阻厚約原0 . 5〜1 // m，整個高寬比將高達4〜6， 所以為增進非等向性蝕刻的能力，係添加某些氣體，如 SiCl 4， CC1 4， CHF3， CHC1舁，利用這些氣體的氯或氟原子 與光阻中的的碳或石夕原子反應形成沉積物，沉積於金屬側 壁上，以避免遭受離子的轟擊。 但這些沉積物與金屬殘存物容易造成晶片污染，如果1242806 V. Description of the invention (1) 1. [Technical field to which the invention belongs] The present invention relates to a method for removing photoresist, and particularly to a method for removing photoresist after the metal layer I is etched. 2. [Previous Technology] In the semiconductor manufacturing process today, the type of material of the metal layer changes with the process going to the nano stage, and its manufacturing process changes accordingly. This article does not affect the implementation of the present invention, which is the most common today. The manufacturing process of aluminum material as a metal layer serves as an introduction to the prior art of the present invention. Aluminum has been widely used in semiconductor processes due to its low resistance, ease of deposition and etching. In advanced integrated circuits, the density of components is limited by the area occupied by the wires, and the anisotropic etching of the metal layer can reduce the spacing between metal wires, thereby increasing the wiring capacity of the wires. Isotropic etching is a very important step in the integrated circuit manufacturing process. In today's processes, due to the reduction in size, the aspect ratio (Aspect Ratio) of the etched pattern increases, making it impossible to discharge the reactants in the money engraving process to form metal residues, plus the thickness of the photoresist is relatively Increasing will make etching more difficult, for example, 0.2 5 // m wide aluminum wire with a thickness of about 0.5 // m, and the photoresist thickness is about 0.5 to 1 // m, the entire aspect ratio will be Up to 4 ~ 6, so in order to improve the ability of anisotropic etching, some gases are added, such as SiCl 4, CC1 4, CHF3, CHC1 舁, the chlorine or fluorine atoms of these gases and the carbon or Shi Xi atoms react to form a deposit, which is deposited on the side wall of the metal to avoid being bombarded by ions. But these deposits and metal residues can easily cause wafer contamination.
1242806 五、發明說明（3) 移除光阻的方法，其包括下列步驟：提供一具有M0S元件 之半導體基底，其上依序形成有一金屬導體層及一圖案化 光阻層；其次，以圖案化光阻層為罩幕，對金屬導體層進 行金屬蝕刻；然後，對該半導體基底進行光阻移除之三步 驟製程，其係先對圖案化光阻層進行一乾式去光阻製程； 接續，以一包含氯化硼、氯與氧粒子的電漿對半導體基底 進行乾式蝕刻；最後對半導體基底進行濕式光阻移除製程 ，即完成移除光組之動作。 茲為使 貴審查委員對本創作之結構特徵及所達成之 功效更有進一步之瞭解與認識，謹佐以較佳之實施例圖及 配合詳細之說明，說明如後： 四、【實施方式】 本發明的方式可被廣泛地應用到半導體製程中許多不 同的金屬層材質蝕刻製程後的光阻移除製程，當本發明以 一較佳實施例來說明本發明方法時，習知此領域的人士應 有的認知是許多的步驟可以改變，金屬層材料及反應所產 生之沉積物也可替換，這些一般的替換無疑地亦不脫離本 發明的精神及範疇。 本發明提出一種在金屬層餘刻後之移除光阻的方法， 其係在傳統的乾式與濕式移除步驟中，加入一乾式蝕刻步 驟，可以移除附著於金屬層側壁之有機與無機沉積物與金 屬殘留物，縮短習知濕式移除光阻製程所需的時間。 第一圖至第五圖為本發明實施例的各步驟之示意圖。 請參閱第一圖所示，其係於一已形成有M0S等基礎元1242806 V. Description of the invention (3) A method for removing a photoresist, which includes the following steps: providing a semiconductor substrate with a MOS device, on which a metal conductor layer and a patterned photoresist layer are sequentially formed; and secondly, using a pattern The photoresist layer is a mask, and the metal conductor layer is subjected to metal etching. Then, a three-step process for removing the photoresist is performed on the semiconductor substrate, which first performs a dry photoresist removal process on the patterned photoresist layer; The semiconductor substrate is dry-etched with a plasma containing boron chloride, chlorine, and oxygen particles. Finally, the semiconductor substrate is subjected to a wet photoresist removal process to complete the removal of the light group. In order to make your reviewing members have a better understanding and understanding of the structural characteristics of this creation and the effects achieved, I would like to provide the preferred embodiment diagrams and detailed descriptions as follows: IV. [Embodiment] The present invention The method can be widely applied to the photoresist removal process after the etching process of many different metal layer materials in the semiconductor process. When the present invention is described by a preferred embodiment, those skilled in the art should It is recognized that many steps can be changed, and the metal layer materials and the deposits produced by the reaction can also be replaced. These general replacements undoubtedly do not depart from the spirit and scope of the present invention. The invention provides a method for removing photoresist after the metal layer is etched. It is a traditional dry and wet removal step, and a dry etching step is added to remove organic and inorganic materials attached to the side wall of the metal layer. Deposits and metal residues shorten the time required for conventional wet removal of photoresist processes. The first to fifth figures are schematic diagrams of steps in the embodiment of the present invention. Please refer to the first figure, which is based on a basic element such as M0S.
1242806 五、發明說明（4) 件的半導體基底10上沈積一材質為鋁的金屬層12，於金屬 層1 2上方形成一圖案化光阻層1 4。 接續，以圖案化光阻 層1 4為罩幕對金屬層1 2進行蝕刻，其中於蝕刻製程中，因 為反應氣氛與金屬層1 2產生反應，導致金屬層1 2侧壁上會 殘留許多含有氯化物或蝕刻殘留氣體之沉積物1 6與因為蝕 刻圖形高的高寬比增加，易產生缺陷金屬殘留物1 8，形成 如第二圖所示之結構。 再，進行一乾式去光阻製程（advanced strip and passivation dry strip， ASP dry strip)，來移除圖案 化光阻層1 4中的有機成份，形成如第三圖所示之結構，其 中該製程係使用氧為氣氛的電漿。 然後，使用三氯化硼（BCI3)、氧氣（〇2)與氯氣 (C 1 Ο的混合氣氛來進行乾式的蝕刻製程，形成如第四圖 所示之結構，其中氧粒子能夠清除如碳氫類的沉積物1 6與 移除殘餘圖案化光阻層1 4中之有機成份，而三氯化硼與氯 能夠輕易的移除沉積物1 6中的無機成份如铭、鈦等金屬， 與金屬殘留物20，其反應式如下： BC1 3-> BC1 2 + C1 C 1 2-> 2 C 1 A 1 + %C 1 2— A 1 C 1 3个1242806 V. Description of the invention (4) A metal layer 12 made of aluminum is deposited on the semiconductor substrate 10 of (4), and a patterned photoresist layer 14 is formed on the metal layer 12. Next, the metal layer 12 is etched by using the patterned photoresist layer 14 as a mask. During the etching process, because the reaction atmosphere reacts with the metal layer 12, many residues on the sidewall of the metal layer 12 will remain. The deposit 16 of the chloride or the etching residual gas and the increased aspect ratio of the etching pattern increase the defect metal residue 18 easily to form a structure as shown in the second figure. Then, an advanced strip and passivation dry strip (ASP dry strip) is performed to remove the organic components in the patterned photoresist layer 14 to form a structure as shown in the third figure, wherein the process The plasma uses oxygen as the atmosphere. Then, a dry etching process is performed using a mixed atmosphere of boron trichloride (BCI3), oxygen (〇2), and chlorine (C 1 0) to form a structure as shown in the fourth figure, in which oxygen particles can remove hydrocarbons such as hydrocarbons. Type of deposits 16 and removal of organic components in the residual patterned photoresist layer 14, and boron trichloride and chlorine can easily remove inorganic components such as Ming, titanium and other metals in the deposits 16, and Metal residue 20, its reaction formula is as follows: BC1 3- > BC1 2 + C1 C 1 2- > 2 C 1 A 1 +% C 1 2— A 1 C 1 3
AlxCyHz + 02— C〇t + H 2〇 t + A1 2〇 3 最後，再進行均向性的濕式光阻移除製程，來移除於 前等向性蝕刻移除製程未能移除乾淨之殘餘光阻1 4與沉積AlxCyHz + 02— C〇t + H 2〇t + A1 2 03 Finally, the isotropic wet photoresist removal process is performed to remove the previous isotropic etching removal process which failed to remove the clean Residual photoresist 14 and deposition
1242806 五、發明說明（5) 物1 6與金屬殘留物1 8，形成如第五圖所示之一完成圖案化 金屬層之半導體基底結構。 因此，本發明可以減少濕式去光阻之溶劑對金屬層造 成的侵蝕造成孔穴的產生，並且避免了習知製程中產生片 狀沉積聚合物剝落導致污染晶片與腔體的危險，此外更可 以獲得更廣的金屬架橋的短路現象。 綜上所述，本發明其係於習知乾式光阻移除製程後， 加入一含有氣化硼、氯與氧粒子的蝕刻工序（r e c i p e )，來 對該半導體基底進行乾式蝕刻，進而能以較短的濕式去光 阻製程時間來獲得與習知同等或較優之移除效用，並且能 夠更有效地移除因增加蝕刻非等向性所產生之沉積物，與 因為製程趨向高度高寬比所導致之金屬殘留物，來降低微 罩幕現象的發生。 惟以上所述者，僅為本發明一較佳實施例而已，並非 用來限定本發明實施之範圍，故舉凡依本發明申請專利範 圍所述之形狀、構造、特徵及精神所為之均等變化與修飾 ，均應包括於本發明之申請專利範圍内。 圖號對照說明： 10半導體基底 12金屬層 1 4圖案化光阻層 1 6沉積物 1 8金屬殘留物1242806 V. Description of the invention (5) The object 16 and the metal residue 18 form a semiconductor base structure in which a patterned metal layer is completed as shown in one of the fifth figures. Therefore, the invention can reduce the generation of cavities caused by the erosion of the metal layer caused by the solvent of the wet photoresist, and avoid the risk of contaminating the wafer and the cavity due to the peeling of the flake-shaped deposition polymer in the conventional manufacturing process. Get wider shorting of metal bridges. In summary, the present invention is based on a conventional dry photoresist removal process, and an etching process (recipe) containing boron gaseous, chlorine, and oxygen particles is added to dry-etch the semiconductor substrate. Shorter wet photoresist process time to achieve the same or better removal effect as known, and can more effectively remove the deposits caused by increased etching anisotropy, and because the process tends to be high The metal residue caused by the aspect ratio reduces the occurrence of micro-masking. However, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of implementation of the present invention. Therefore, for example, changes in shape, structure, characteristics, and spirit in accordance with the scope of the patent application for the present invention are equivalent. Modifications should be included in the scope of patent application of the present invention. Comparative illustration of drawing numbers: 10 semiconductor substrate 12 metal layer 1 4 patterned photoresist layer 1 6 deposit 1 8 metal residue
1242806 圖式簡單說明 第一圖至第五圖為本發明之各步驟示意圖。 画_ 第10頁1242806 Brief description of the drawings The first to fifth drawings are schematic diagrams of the steps of the present invention. Painting _ page 10