535222 五、發明說明（1) 本發明是有關一種半導體沉積製程，且特別是有關於 一種利用電漿化學氣相沉積法（p 1 a s m a e n h a n c e d chemical vapor deposition，簡稱PECVD)沉積薄膜的方 法。 目前化學氣相沉積製程已經是半導體製程中最重要與 主要的薄膜沉積製程。舉凡所有半導體元件所需要的薄 膜，無論是導體、半導體或是介電材料（(11616以1^以）都 可以藉由化學氣相沉積法來製得。因為化學氣相沉積是藉 由反應氣體間的化學反應來產生所需的薄膜，所以利用此 法所製作的薄膜材料在結晶性（c r y s t a 1 1 i n i t y )和理想配 比（stoichiometry )等與材質特性相關的一些性質上較為 優良。 而為了降低反應所需的溫度’以達到調降製程熱預算 (thermal budget)的目的，所謂的「電漿化學氣相沉積 法」已逐漸成為主要的薄膜沉積製程之一。通常在電漿化 學氣相沉積腔體（PECVD chamber)内，於基板上沉積薄膜 的方法包括施行電漿化學氣相沉積製程，然後在無基板的 情形下清潔腔體，再進行預沉積（p r e - d e ρ 〇 s i t i 〇 η )製程， 以隔絕來自清潔腔體之製程中的污染物 (contamination)。之後，再進行下一個沉積製程。 然而’當沉積在基板上的薄膜是一種絕緣材質層 (insulating material layer)或是高電阻的薄膜如本徵 ^ BB ^(intrinsic amorphous silicon)日寺，電浆 匕學氣 相腔體器壁和電極的表面會累積大量電荷。此時，如欲繼535222 V. Description of the invention (1) The present invention relates to a semiconductor deposition process, and in particular, to a method for depositing a thin film by plasma chemical vapor deposition (p 1 a s m a n h a n c e d chemical vapor deposition, referred to as PECVD). At present, the chemical vapor deposition process is the most important and main thin film deposition process in the semiconductor process. For example, all the thin films required for semiconductor devices, whether they are conductors, semiconductors, or dielectric materials ((11616 to 1 ^)) can be made by chemical vapor deposition. Because chemical vapor deposition is made by reactive gases In order to produce the required thin film, the thin film material produced by this method is excellent in some properties related to material properties such as crystallinity (1 inity) and stoichiometry (stoichiometry). To reduce the temperature required for the reaction 'in order to reduce the thermal budget of the process, the so-called "plasma chemical vapor deposition" has gradually become one of the main thin film deposition processes. Usually in the plasma chemical vapor phase In a PECVD chamber, a method for depositing a thin film on a substrate includes performing a plasma chemical vapor deposition process, then cleaning the chamber without a substrate, and then performing pre-deposition (pre-de ρ 〇siti 〇η ) Process to isolate contamination from the process of cleaning the cavity. After that, the next deposition process is performed. However ' When the thin film deposited on the substrate is an insulating material layer or a high-resistance thin film such as intrinsic ^ BB ^ (intrinsic amorphous silicon) Risi, the plasma wall of the gas phase cavity and the electrode A large amount of charge can accumulate on the surface.
9458twf.ptd 535222 五、發明說明（2) 續進行下一批基板的薄膜沉積，則電漿的分佈形狀將會受 到累積電荷分佈不均的影響，而造成沉積後的薄膜膜厚均 勻度變差。 因此，本發明的目的在提供一種利用電漿化學氣相沉 積法沉積薄膜的方法，以降低腔體内器壁和電極表面之累 積電荷。 本發明的再一目的在提供一種利用電漿化學氣相沉積 法沉積薄膜的方法，以避免電漿的分佈形狀受到累積電荷 分佈不均的影響。 本發明的另一目的在提供一種利用電漿化學氣相沉積 法沉積薄膜的方法，以改善薄膜厚度之均勻度。 根據上述與其它目的，本發明提出一種利用電漿化學 氣相沉積法沉積薄膜的方法，係於一電漿化學氣相沉積腔 體中，以電漿輔助化學反應，在基板上形成薄膜。接著待 取出基板後，將清潔氣體（cleaning gas)導入腔體中，以 去除腔體内的附著物。隨後，在基板置入腔體前施行一預 沉積（p r e - d e ρ 〇 s i t i ο η )製程，以隔絕來自清潔製程的污染 物。然後，施行一放電電漿處理（d i s c h a r g e ρ 1 a s m a t r e a t m e n t)，再進行下一批基板的利用電漿化學氣相沉積 法沉積薄膜的方法。 本發明係藉由預沉積之後的放電電漿處理，大量降低 腔體内器壁和電極表面的累積電荷數目，以使累積電荷的 影響變小，進而改善沉積薄膜的厚度均勻度。 為讓本發明之上述和其他目的、特徵和優點能更明顯9458twf.ptd 535222 V. Description of the invention (2) When the film deposition of the next batch of substrates is continued, the distribution shape of the plasma will be affected by the uneven distribution of the accumulated charge, resulting in poor uniformity of the film thickness after deposition . Therefore, an object of the present invention is to provide a method for depositing a thin film by a plasma chemical vapor deposition method, so as to reduce the accumulated charges on the inner wall of the cavity and the surface of the electrode. Yet another object of the present invention is to provide a method for depositing a thin film by a plasma chemical vapor deposition method, so as to prevent the distribution shape of the plasma from being affected by the uneven distribution of the accumulated charge. Another object of the present invention is to provide a method for depositing a thin film by a plasma chemical vapor deposition method to improve the uniformity of the thickness of the thin film. According to the foregoing and other objectives, the present invention proposes a method for depositing a thin film by using a plasma chemical vapor deposition method, which is formed in a plasma chemical vapor deposition chamber and uses a plasma to assist a chemical reaction to form a thin film on a substrate. After the substrate is taken out, a cleaning gas is introduced into the cavity to remove the attachments in the cavity. Subsequently, a pre-deposition (pre-d e ρ s s i t i ο η) process is performed before the substrate is placed in the cavity to isolate contaminants from the cleaning process. Then, a discharge plasma treatment (d i s c h a r g e ρ 1 a s m a t r e a t m e n t) is performed, and then a method of depositing a thin film by plasma chemical vapor deposition method for the next batch of substrates is performed. The present invention uses a discharge plasma treatment after pre-deposition to greatly reduce the number of accumulated charges on the wall of the cavity and the surface of the electrode, so as to reduce the effect of the accumulated charges, thereby improving the thickness uniformity of the deposited film. To make the above and other objects, features, and advantages of the present invention more apparent
9458twf.ptd 第6頁 535222 五、發明說明（3) 易懂，下文特舉一較佳實施例，並配合所附圖式，作詳細 說明如下： 標記之簡單說明： 1 0 0 :施行電漿化學氣相沉積，以於基板上形成薄膜 1 1 0 :取出基板 1 2 0 :進行一清潔製程 1 3 0 :進行一預沉積製程 1 4 0 :施行一放電電漿製程 1 5 0 :放入下一批基板 實施例 本發明疋一種利用電漿化學氣相沉積法（p 1 a s m a enhanced chemical vapor deposition，簡稱PECVD)沉積 薄膜的方法，主要是在進行預沉積製程（pre-deposition process)後，施行一放電電漿製程（discharge plasma treatment) ’藉以大量降低腔體（chamber)内器壁和電極 表面的累積電荷數目，以使累積電荷的影響變小，進而改 善沉積薄膜的厚度均勻度。而本發明可廣泛應用於半導體 製程中，譬如以下的實施例。 第1圖是依照本發明一較佳實施例之利用電漿化學氣 相沉積法沉積薄膜的方法的步驟圖。 請參照第1圖，於步驟丨〇 〇，施行電漿化學氣相沉積， 以於基板上形成薄膜，係對置於電漿化學氣相沉積腔體中 的基板’以電漿輔助化學反應，在其上形成一層薄膜，直 到完成沉積製程。9458twf.ptd Page 6 535222 V. Description of the invention (3) It is easy to understand. The following is a detailed description of a preferred embodiment and the accompanying drawings, which are described in detail as follows: A brief description of the mark: 1 0 0: implementation of plasma Chemical vapor deposition to form a thin film on a substrate 1 1 0: Take out the substrate 1 2 0: Perform a cleaning process 1 3 0: Perform a pre-deposition process 1 4 0: Perform a discharge plasma process 1 50: Place Next batch of substrate examples The present invention is a method for depositing a thin film by plasma chemical vapor deposition (p 1 asma enhanced chemical vapor deposition (PECVD)), which is mainly performed after a pre-deposition process. A discharge plasma treatment is performed to reduce the number of accumulated charges in the chamber wall and the electrode surface in a large amount so as to reduce the effect of the accumulated charges and improve the thickness uniformity of the deposited film. The present invention can be widely used in semiconductor processes, such as the following embodiments. FIG. 1 is a step diagram of a method for depositing a thin film by a plasma chemical vapor deposition method according to a preferred embodiment of the present invention. Please refer to FIG. 1. In step 丨 00, plasma chemical vapor deposition is performed to form a thin film on the substrate, and the substrate 'placed in the plasma chemical vapor deposition chamber is plasma-assisted chemical reaction. A thin film is formed thereon until the deposition process is completed.
535222 五、發明說明（4) 之後，於步驟11 〇中，取出基板，係於保持腔體真空 下將基板由電漿化學氣相沉積腔體取出。 之後，於步驟120中，進行一清潔製程（cieaning)， 係將清潔氣體（cleaning gas)導入腔體内，以電聚輔助化 學反應去除其中的附著物，用以改善微粒（particle)的問 題，其中清潔氣體例如是含有氟基的氣體，譬如三氟化氮 (NF3)。 ° 接著’於步驟1 3 0中’進行一預沉積製程，主要是在 無基板的狀態下進行沉積製程，以隔絕來自清潔製程中的 污染物（contamination)，譬如I離子。 然後，於步驟1 4 0中，施行一放電電漿處理，尤其是 當沉積的薄膜是一種絕緣材質層（insulaUng material layer)或是高電阻的薄膜如本徵非晶矽（intrinsic amorphous silicon)時’腔體内電極的表面會累積大量電 荷，而V致電桌刀佈文到累積電荷分佈不均的影響，造成 膜厚均勻度變差。所以，本發明在預沉積製程之後再施行 ' 放電電聚處理’其中所伟田沾名舰A 卜 q便用的乳體係選自於包括氫氣535222 5. Description of the invention (4), in step 110, the substrate is taken out, and the substrate is taken out from the plasma chemical vapor deposition chamber while maintaining the cavity vacuum. Then, in step 120, a cleaning process is performed. The cleaning gas is introduced into the cavity, and the adhesion is removed by the electro-assisted chemical reaction to improve the problem of particles. The cleaning gas is, for example, a fluorine-containing gas, such as nitrogen trifluoride (NF3). ° Next, a pre-deposition process is performed in step 130. The main process is to perform the deposition process without a substrate to isolate contamination from cleaning processes, such as I ions. Then, in step 140, a discharge plasma treatment is performed, especially when the deposited film is an insulating material layer (insulaUng material layer) or a high-resistance film such as intrinsic amorphous silicon. 'The surface of the electrode in the cavity will accumulate a large amount of charge, and V calls the table knife to the effect of uneven distribution of accumulated charge, resulting in poor film thickness uniformity. Therefore, after the pre-deposition process of the present invention, the 'discharge electro-polymerization treatment' is performed. The milk system used by the Weitian Zhanmingship A bu q is selected from the group consisting of hydrogen.
(112)、氮氣（%)、氬氣（八1^、^|^^^[、|, ^ ^ A uv/ir)、乱軋（He)或上述氣體的混合 氣體之族群。 之後，於步驟1 50中，访人丁 .L . t 放入下一批基板，以重複步驟 1 0 0進行薄膜沉積。 綜上所述’本發明之特徵包括： 1 ·本發明係在預沉藉制名口々祕 工， ^ . % 、。檟衣私之後，再施行一放電電槳處 理，以大量降低當沉積薄膜I π # #所@ ^ ^ ^ 狀碍膝疋絶緣材質層或高電阻薄膜(112), nitrogen (%), argon (eight 1 ^, ^ | ^^^ [, |, ^ ^ A uv / ir), random rolling (He), or a mixture of the above gases. After that, in step 150, the visitor D.L.t is put into the next batch of substrates, and the step 100 is repeated for thin film deposition. To sum up, the features of the present invention include: 1. The present invention is a famous worker in the pre-sink loan system, ^.%. After the clothing is worn, a discharge electric paddle treatment is performed to greatly reduce the thickness of the deposited film I π # # 所 @ ^ ^ ^
535222 五、發明說明（5) 時，腔體内器壁和電極的表面所累積的電荷。 2. 本發明由於能夠降低累積電荷的數目，所以可使累 積電荷對電漿分佈的影響變小。 3. 由於本發明利用放電電漿處理降低累積電荷，因此 能夠改善沉積薄膜的厚度均勻度。 雖然本發明已以一較佳實施例揭露如上，然其並非用 以限定本發明，任何熟習此技藝者，在不脫離本發明之精 神和範圍内，當可作些許之更動與潤飾，因此本發明之保 護範圍當視後附之申請專利範圍所界定者為準。535222 5. In the description of the invention (5), the electric charge accumulated in the cavity wall and the surface of the electrode. 2. Since the present invention can reduce the number of accumulated charges, the influence of the accumulated charges on the plasma distribution can be made small. 3. Since the present invention uses a discharge plasma treatment to reduce the accumulated charge, the thickness uniformity of the deposited film can be improved. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application.
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