1281714 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種用來移除表面沉積物的方法，是藉著 使用一種以遠距活化含氧及氟碳化物之氣體混合物所創造 的經活化氣體。更特定地，本發明係關於一種用來從化學 蒸氣沉積室的内面移除表面沉積物的方法，使用含氧及氟 碳化物之經遠距活化的氣體混合物。 【先前技術】 用來生產原子氟的遠距電漿來源被廣泛用於半導體製程 工業中的室清潔，特別是在清潔化學蒸氣沉積（CVD)及電漿 增進化學蒸氣沉積（PECVD)所用的室（chambers)。遠距電漿 來源的使用避免一些室内面材質的腐蝕，其在就地室清潔 時發生，其中該清潔是在PECVD室中、以創造電漿放電來 進行。當電容性及感應性偶合RF及微波遠距來源被發展用 於這些種類的用途時，該工業快速移向變壓器偶合之導電 偶合來源’其中電浆具有超環面（torroidal)型態，並且作為 變壓器的第一線（secondary)。較低rf動力的使用容許使用 磁核心，其增進與電容性偶合之感應性偶合；因此容許更 有效轉移能量到電漿，而無過量的離子撞擊，其限制了遠 距電漿來源室内面的壽命。 半導體工業對室清潔從氟碳化物與氧的混合物移開，該 混合物起初因許多理由而為用於就地室清潔的主要氣體。 首先，來自此類製程之全球溫室氣體的排放，一般是比三 氟化氮（NF3)製程的高出許多。NF3在放電中更容易解離， 102525.doc 1281714 並且不由產物種類的再組合而大大地形成。因此，低量全 球溫室排放可更容易地達成。對照下，氟碳化物類較難在 放電中被分解，並且再組合形成如：四氟甲烧（CF4)的物 種，其比其他氟碳化物更難被分解。 第二，一般發現：氟碳化物放電產生”聚合物"沉積，其 需要更經常的濕清潔，以移除這些在重覆乾清潔之後累積 的沉積物。氟碳化物清潔成沉積”聚合物，，的趨勢在遠距清 潔中發生較大量，其中無離子撞擊在清潔期間發生。這些 觀察勸離工業界發展以氟碳化物進料氣體為基礎的工業製 程。事實上，PECVD設備製造商測試以氟碳化物放電為基 礎的遠距清潔，但至今不成功，因為聚合物沉積在製程室 中。 然而，若上述的兩個缺點可被解決，氟碳化物氣體對其 低成本及低毒性為理想的。 【發明内容】 本發明係關於一種用來移除表面沉積物的方法，該方法 包含：（a)在遠室中活化一種含氧及氟碳化物之氣體混合 物，其中氧及氟碳化物之莫耳比率為至少丨：4，使用足^ 的動力達一段足夠時間，使得該氣體混合物達到至少約 3,000 K的中和溫度，以形成經活化之氣體混合物；及之後 ⑻將該經活化之氣體混合物與表面沉積物接觸，並且因此 移除至少一些該表面沉積物。 在本發明中之表面沉積物移除’包含一般以化學蒸氣沉 積、或電漿增進化學蒗氣沉籍、七4,s y、，在 予…礼儿積、或類似製程所沉積的那些 102525.doc 12817141281714 IX. DESCRIPTION OF THE INVENTION: FIELD OF THE INVENTION The present invention relates to a method for removing surface deposits by using a gas mixture created by remotely activating a mixture of oxygen and fluorocarbons. gas. More particularly, the present invention relates to a method for removing surface deposits from the inner surface of a chemical vapor deposition chamber using a remotely activated gas mixture containing oxygen and fluorocarbons. [Prior Art] The source of remote plasma used to produce atomic fluorine is widely used for chamber cleaning in the semiconductor process industry, particularly in clean chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition (PECVD) chambers. (chambers). The use of remote plasma sources avoids corrosion of some interior materials that occur during cleaning of the in-place chamber where the cleaning is performed in a PECVD chamber to create a plasma discharge. When capacitive and inductively coupled RF and microwave remote sources are being developed for these types of applications, the industry rapidly moves to a conductive coupling source where the transformer is coupled, where the plasma has a toroidal type and acts as The first line of the transformer. The use of lower rf power allows the use of a magnetic core that enhances the inductive coupling with capacitive coupling; thus allowing more efficient transfer of energy to the plasma without excessive ion impact, which limits the interior of the remote plasma source life. The semiconductor industry's cleaning of the chambers is removed from the mixture of fluorocarbons and oxygen, which was originally the primary gas used for cleaning the in-situ chamber for a number of reasons. First, global greenhouse gas emissions from such processes are generally much higher than those of the nitrogen trifluoride (NF3) process. NF3 is more readily dissociated during discharge, 102525.doc 1281714 and is not greatly formed by recombination of product species. Therefore, low-volume global greenhouse emissions can be achieved more easily. In contrast, fluorocarbons are more difficult to decompose in the discharge and are combined to form a species such as tetrafluoromethane (CF4) which is more difficult to decompose than other fluorocarbons. Second, it has been generally found that fluorocarbon discharge produces "polymer" deposits that require more frequent wet cleaning to remove these deposits that accumulate after repeated dry cleaning. Fluorocarbons are cleaned into deposited "polymers." The trend of , is a large amount in remote cleaning where no ion impact occurs during cleaning. These observations advise the industry to develop industrial processes based on fluorocarbon feed gases. In fact, PECVD equipment manufacturers tested remote cleaning based on fluorocarbon discharges, but have so far been unsuccessful because polymers are deposited in the process chamber. However, if the above two disadvantages can be solved, fluorocarbon gas is desirable for its low cost and low toxicity. SUMMARY OF THE INVENTION The present invention is directed to a method for removing surface deposits, the method comprising: (a) activating a gas mixture of oxygen and fluorocarbons in a remote chamber, wherein oxygen and fluorocarbons are The ear ratio is at least 丨: 4, using sufficient power for a period of time such that the gas mixture reaches a neutralization temperature of at least about 3,000 K to form an activated gas mixture; and thereafter (8) the activated gas mixture Contact with surface deposits, and thus at least some of the surface deposits are removed. The surface deposit removal in the present invention 'contains those generally deposited by chemical vapor deposition, or plasma enhanced chemical helium, seven 4, sy, deposited in a singular product, or the like. Doc 1281714
物質。此類物質包括：矽、經摻雜的矽、氮化矽、鶴、二 氧化矽、氧基氮化矽、碳化矽及被稱為低κ材質之不同矽氧 化合物’如：FSG(氟化矽酸鹽玻璃）&sic〇H、或pECVD OSG ’ 包括 Black Diamond(Applied Materials)、Coral (Novellus Systems)及 Aurora(ASM International)。 本發明的一個具體實施例是從製程室的内面移除表面沉 積物，該室被用於製造電子裝置。此製程室可為化學蒸氣 _ 沉積（CVD)室或電漿增進化學蒸氣沉積（pecvd)室。 本發明的製程牵涉到使用足夠動力的活化步驟，以形成 具有中和溫度至少約3,〇〇〇 κ的經活化氣體。活化可以容許 達成大部份進料氣體解離的任何方式完成，如·· RF能量、 DC旎I、雷射照度及微波能量。所得電漿的中和溫度取決 於動力及氣體混合物在遠室中的滯留時間。在某些動力輸 出及條件下，中和溫度隨較長的滯留時間而更高。在此， 較佳中和溫度會高過約3,000 K。在適當條件下（考慮動力、 _ 氣體組合物、氣壓及氣體滞留時間），可達到至少約6〇〇〇 κ 的中和溫度，例如：以八氟環丁烷。 經活化氣體在製程室外面的遠室中形成，但其彳艮接近 ^ 、土 ^ 乂 。“运室是以容許轉移經活化氣體從遠室到製程室的 <何方式連接到製程室。遠室及用來連接遠室及製程室的 ，曰 ^ ’疋以此領域已知能夠包含經活化氣體混合物的材質 所建構。你1 士 · •銘及不鏽鋼一般使用於室組份。有時候，substance. Such materials include: cerium, doped cerium, cerium nitride, crane, cerium oxide, cerium oxynitride, cerium carbide and different cerium oxides known as low κ materials such as: FSG (fluorinated Tellurite glass) &sic〇H, or pECVD OSG' includes Black Diamond (Applied Materials), Coral (Novellus Systems), and Aurora (ASM International). One embodiment of the present invention removes surface deposits from the interior of the process chamber that are used to fabricate electronic devices. The process chamber can be a chemical vapor deposition (CVD) chamber or a plasma enhanced chemical vapor deposition (pecvd) chamber. The process of the present invention involves the use of a sufficient power activation step to form an activated gas having a neutralization temperature of at least about 3, 〇〇〇 κ. Activation can be accomplished in any way that allows most of the feed gas to dissociate, such as RF energy, DC 旎I, laser illuminance, and microwave energy. The neutralization temperature of the resulting plasma depends on the residence time of the power and gas mixture in the remote chamber. Neutralization temperatures are higher with longer residence times under certain power output and conditions. Here, the preferred neutralization temperature will be higher than about 3,000 K. Under appropriate conditions (considering kinetics, gas composition, gas pressure and gas residence time), a neutralization temperature of at least about 6 κ κ can be achieved, for example, with octafluorocyclobutane. The activated gas is formed in the far chamber outside the process chamber, but its enthalpy is close to ^, soil ^ 乂. “The operation room is connected to the process chamber by allowing the transfer of activated gas from the remote chamber to the process chamber. The remote chamber and the connection between the remote chamber and the process chamber are known to be included in this field. Constructed from the material of the activated gas mixture. You 1st • Ming and stainless steel are generally used in the room components. Sometimes,
Al2〇3塗覆在内面，以減少表面再組合。 才皮、、舌 y/U 、 彳 以形成活化氣體的氣體混合物包含氧及氟碳化 102525.doc 1281714 物。本發明的氟碳化物在此被指為含C及F的化合物。本發 明中的較佳氟碳化物為全氟碳化物化合物。本發明中的全 氟碳化物化合物在此被指為由C、F及視情況有氧所構成的 化合物。此類全氟碳化物化合物包括、但不限於：四氟曱 烧、六氟乙烷、八氟丙烷、六氟環丙烷、十氟丁烷、八氟 % 丁烧、幾基氟及八氟四氫呋喃。較佳的全氟碳化物為八 氟環丁烧。 被活化以形成活化氣體的氣體混合物可進一步包含載體 氣體’如：氮、氬及氦。 在活化步驟期間，遠室中的總壓可在約0.5托（torr)及約20 托之間。 氣體混合物包含氧及氟碳化物的莫耳比率為至少1 : 4。 在本發明中所用的高中和溫度條件下，超過10莫耳百分比 化學計量需求的氧(即：在氟碳化物中需要轉化所有碳成為 C〇2之虱份量）造成令人驚訝之良好沉積室清潔速率，排除 除了 C0F2的氟奴化物放電，並且避免氟碳化物聚合物沉積 物在沉積表面。 ' 孔胜此合物使用足夠的動力活化一段足夠的時間，使得Al2〇3 is coated on the inner surface to reduce surface recombination. The gas mixture of the skin, y/U, and 彳 to form an activating gas comprises oxygen and fluorocarbonization 102525.doc 1281714. The fluorocarbon of the present invention is referred to herein as a compound containing C and F. Preferred fluorocarbons in the present invention are perfluorocarbon compounds. The perfluorocarbon compound in the present invention is herein referred to as a compound composed of C, F and optionally aerobic. Such perfluorocarbon compounds include, but are not limited to, tetrafluoroanthracene, hexafluoroethane, octafluoropropane, hexafluorocyclopropane, decafluorobutane, octafluoro% butyl, hexafluoro, and octafluorotetrahydrofuran. . A preferred perfluorocarbon is octafluorocyclobutane. The gas mixture activated to form the activating gas may further comprise carrier gases such as nitrogen, argon and helium. During the activation step, the total pressure in the remote chamber can be between about 0.5 torr and about 20 torr. The gas mixture comprises oxygen and fluorocarbons in a molar ratio of at least 1:4. Under the high and temperature conditions used in the present invention, more than 10 mole percent of the stoichiometric oxygen required (i.e., the need to convert all of the carbon to a 〇2 amount in the fluorocarbon) results in a surprisingly good deposition chamber. The cleaning rate excludes the fluocyanide discharge in addition to COF2 and avoids fluorocarbon polymer deposits on the deposition surface. 'Kong Sheng this compound uses enough power to activate for a sufficient period of time, making
〗合物的滞留時間必須足夠，使得氣 000 K的中和溫度。對適當條件（考慮 102525.doc 1281714 如··氧、氟碳化物、氬）從左邊被導入遠距電漿來源丨，並 且通過超環面放電，在此以400千赫兹（KHz)無線電頻率動 力3放電，形成經活化的氣體混合物。磁核心*係用於增進 與電容性偶合之感應性偶合。氧由Airgas製造，具99·999% 純度。氟碳化物為Zyron® 8020,由DuPont製造，具最少99·9 體積％的八氟環丁烷。氬由Airgas製造，具5〇等級。然後 系二活化的氣體通過藉冷卻水冷卻的鋁熱交換器，減少鋁製 程室的熱負載。經表面沉積物覆蓋之晶圓7被置於在製程室 ® 6中的溫度控制架8上。中和溫度以光學放射光譜儀⑴es) 測量，其中如：像是(^及川之二原子物種的振轉轉移帶， 理論上適於產生中和溫度。也見B Bai及H. Sawin，journai of Vacuum Science & Technology A 22(5)，2014(2004)，在此 併為參考。以經活化氣體之表面沉積物的蝕刻速率，以干 涉（interferometry)設備在製程室中測量。n2氣體9在泵1〇的 進口處被添加，以稀釋產物到適於FTIR測量的濃度，並且 φ 減少產物在泵中的擱置。FTIR被用來測量在泵出口處的物 種濃度。 實例1 進料氣體包含〇2、全氟碳化物及Ar，其中全氟碳化物為 Zyron® 8020(C4F8)、C3F8、C2F6或 CF4。在此實例中，全氟 碳化物的流速被調整，使得元素氟進入遠室的莫耳流速對 所有的混合物皆相同。在此實例中，C4F8、C3F8、C2F6及 CFU的流速分另為每分鐘250、250、333及500標準毫升，其 都相當於每分鐘2000標準毫升的元素氟。02對〇2與全氟碳 102525.doc 1281714 6 製程室 9 N2氣體 10 泵 102525.doc -17The residence time of the compound must be sufficient to allow a neutralization temperature of 000 K. The appropriate conditions (considering 102525.doc 1281714 such as oxygen, fluorocarbons, argon) are introduced into the remote plasma source from the left side and passed through a toroidal discharge, which is powered by a 400 kHz radio frequency. 3 Discharges to form an activated gas mixture. The magnetic core* is used to enhance the inductive coupling with capacitive coupling. Oxygen is manufactured by Airgas and has a purity of 99.999%. The fluorocarbon is Zyron® 8020, manufactured by DuPont, with a minimum of 99.9% by volume of octafluorocyclobutane. Argon is manufactured by Airgas and has a rating of 5 inches. The second activated gas is then passed through an aluminum heat exchanger cooled by cooling water to reduce the thermal load on the aluminum process chamber. The wafer 7 covered by the surface deposit is placed on the temperature control rack 8 in the process chamber ® 6. The neutralization temperature is measured by an optical emission spectrometer (1) es), such as: a vibration transfer belt such as (^ and Chuanzhi diatomic species, theoretically suitable for generating neutralization temperature. See also B Bai and H. Sawin, journai of Vacuum Science & Technology A 22 (5), 2014 (2004), incorporated herein by reference. Measured in the process chamber by an interferometry device at an etch rate of the surface deposit of the activated gas. n2 gas 9 is at the pump An inlet of 1 Torr was added to dilute the product to a concentration suitable for FTIR measurement, and φ reduced the shelf life of the product in the pump. FTIR was used to measure the concentration of the species at the pump outlet. Example 1 The feed gas contained 〇2 , perfluorocarbons and Ar, wherein the perfluorocarbons are Zyron® 8020 (C4F8), C3F8, C2F6 or CF4. In this example, the flow rate of the perfluorocarbons is adjusted so that elemental fluorine enters the far chamber of the moir The flow rate is the same for all mixtures. In this example, the flow rates of C4F8, C3F8, C2F6, and CFU are typically 250, 250, 333, and 500 standard milliliters per minute, which are equivalent to 2000 standard milliliters of elemental fluorine per minute. 02 pairs of 〇2 and perfluoro Carbon 102525.doc 1281714 6 Process chamber 9 N2 gas 10 pump 102525.doc -17