201002857 六、發明說明： 〔相關申請案〕 本申凊案係依據在2008年4月22日於日本所申請之 特願2008 — 111377號主張優先權。 【發明所屬之技術領域】 本發明係有關一種電漿成膜裝置之清洗方法，且有關 在使用含有矽之成膜用氣體形成薄膜後，將含有氟之氣體 電漿化來進行清洗之方法者。 〆 【先前技術】 在電子裝置製造流程中，存在有大量的形成矽氧化膜 和矽氮化膜之絕緣膜之步驟。形成此等絕緣膜之方法大多 使用電漿CVD法（pECVD)。在同流程中，隨著成膜處理 的進行’主要為成膜成分之固體狀堆積物也於反應室内及 其排氣管線内蓄積。 由於此固體狀堆積物會造成成膜狀態異常、產生顆 I 粒、排氣管線阻塞’故必須依累積膜厚和成膜頻率而清洗 反應室内部及排氣管線。 做為此清洗方法，廣泛地普遍使用藉由活性氟原子使 固體狀堆積物進行化學變化成為四氟化矽（SiF4)等揮發 性氣化物後做為排氣排出而去除之乾清洗。 為了生成活性氟原子，而使用在分子内具有氟原子之 氣體，一般使用將四氟甲烷（CFO或六氟乙烷（c2F6)之 全氟取代化合物（PFC)電漿化之方法（非專利文獻D。 然而此等pFC氣體係使地球溫暖化之氣體（非專利 321131 3 201002857 文獻2 )。 在半導體產業中，關於此等地球温暖化物質，已揭示 以1995年做為基準，直到2010年為止削減10%之目標。 做為削減PFC氣體之排出量之清洗方法，本申請人於 先前已申請有使用在分子内具有氫原子之氫氟碳氣體 (hydrofluorocarbon gas)之所謂替代氣體來進行電漿處理之 方法。 此前案發明中所揭示之清洗方法係將由四氟乙烷、五 氟乙烷等氫氟碳氣體組成之替代氣體、與氧氣等含有氧之 氣體之混合氣體做為清洗用氣體使用，並藉由電漿處理進 行清洗之方法。 然而，使用此種替代氣體時，一般，從替代氣體本身 之物性、或替代氣體與氧之混合比率之關係來看，電漿處 理時之放電電壓（Vpp )升高、或自偏壓（self bias) ( Vdc) 朝負值側變動之傾向強。 所謂放電電壓，係指施加於電極間之高頻電壓之正電 位與負電位間之峰間之電壓（peak to peak voltage )，且為 電衆放電（plasma discharge)所需之電壓。此外，所謂自偏 壓，係指放電電壓之1/2之位置之電壓。 若放電電壓較習知之條件更極度升高、或自偏壓變成 較大的負值，則在電漿生成時，容易產生所謂電弧放電 (arcing)之電聚之局部性異常放電。 電弧之產生除了會難以推動用以進行正常的清洗之 電漿支援化學反應以外，也會使反應室内之各種零件受 4 321131 201002857 損，而造成壽命縮短、或成膜異常。因此，必須以不會使 電弧產生之方式控制電漿。 放電電壓以具有與習知之清洗方法中之值為同等之 值者為佳，並期待使自偏壓也同樣不會成為大的負值之電 位的方式而維持電漿。 〔非專利文獻 1〕Mocella，M. t. Mat. Res. Soc. Symp. Proc. 447 ( Environmental, Safety and Health Issues in IC Production) ,29 ( 1997). 〔非專利文獻 2〕Ehhalt, D. ; Prather，M. Intergovernmental Panel on Climate Change( IPCC ), Climate Change 2001 ： The Scientific Basis. Atmospheric Chemistry and Greenhouse Gases ( 2001 ). 〔非專利文獻3〕日本電子資訊技術產業協會.報導 發表，「關於第9次世界半導體會議（WSC )之結果」 http://semicon.jeita.or.jp/docs/wsc.pdf ( 2005 ). ^ 【發明内容】 (發明欲解決的課題） 因此’本發明之課題在於：在將氫氟碳氣體與氧氣之 混合氣體做為清洗用氣體使用並藉由電漿處理進行清洗 時，抑制電弧放電之產生而不會使反應室内之各種零件受 損，而不會發生成膜異常等。 (解決課題的手段） 為了解決如此之課題，本發明提供一種電漿成膜裝置 之清洗方法’係去除堆積於電漿CVD成膜裝置之反應室 321131 5 201002857 及排氣管線内之堆積物之方法，其中， 使用含有氫氟碳氣體、氧氣與解離性氣體且解離性氣 體之比例為氫氟碳氣體與氧氣之合計量之5至lOvol%之 混合氣體做為清洗用氣體來進行電漿處理。 在本發明中’氮氣碳氣體以五氣乙烧氣體 (pentafluoroethanegas)為佳。 此外，解離性氣體以從由CF4、C2F6、C3F8、C-C4F8 (環狀C4F8)、NF3、N20所成群組中選出之1種以上為佳。 (發明的效果） 根據本發明，因使用含有氫氟碳氣體、氧氣與解離性 氣體且解離性氣體之比例為氫氟碳氣體與氧氣之合計量之 5至lOvol%之混合氣體做為清洗用氣體，而在電漿處理 時，放電電壓與使用習知之清洗用氣體時者幾乎相同且不 會任意升高，而且自偏壓也不會成為大的負值。 因此，所謂電弧之電漿之局部性異常放電之產生受到 抑制，而不會使反應室内之各種零件受損，而不會發生成 膜異常等。 此外，地球溫暖化物質之排出量也減少。 【實施方式】 第1圖係表示用以實施本發明之清洗方法之電漿 CVD成膜裝置之例子者。 此電漿CVD成膜裝置係具備從高頻電源1施加高頻 電力使電漿產生之平行平板型等之電漿產生手段2，且大 致由下述所構成：用以在電漿環境中於基板上形成氧化矽 6 321131 201002857 等薄膜之反應室3、將成膜用氣體導入至此反應室3内之 原料氣體導入管4、將構成清洗用氣體之鼠鼠碳氣體送入 至反應室3内之第1導入管5、將構成清洗用氣體之氧氣 送入至反應室3内之第2導入管6、將構成清洗用氣體之 解離性氣體送入至反應室3内之第3導入管7、與具備排 出反應室3内之氣體之排氣泵9之排氣管8。 前述電漿產生手段2係具備使成膜用氣體及清洗用氣 體流出之蓮蓬頭21、與載置基板之基座（susceptor) 22， 且形成為於蓮蓬頭21與基座22間從高頻電源1施加高頻 電力之狀態。 前述原料氣體導入管4、第1導入管5、第2導入管6 與第3導入管7係與蓮蓬頭21導通，而形成為使成膜用氣 體與清洗用氣體從蓮蓬頭21朝基板流出。 在藉由此成膜裝置進行成膜時，於反應室3内之基座 22上配置矽基板等基板，並從原料氣體導入管4將包含四 乙氧基矽烷、氧氣、氮氣、氨氣等之原料氣體導入至反應 室3内後，使其從蓮蓬頭21流出，並啟動電漿產生手段2, 藉由電漿CVD反應於基板上形成氧化膜等薄膜。藉由排 氣泵9抽吸使反應室3内之氣體從排氣管8排出。 在清洗電漿CVD成膜裝置之反應室3及其排氣管8 之内部時，從第1導入管5經由質量流量計10將預定量之 氫氟碳氣體送入反應室3内，從第2導入管6經由質量流 量計11將預定量之氧氣送入反應室3内，從第3導入管7 經由質量流量計12將解離性氣體送入。 7 321131 201002857 〜然後二在蓮蓬頭21與基座22間從高頻電源【施加預 疋電力之南頻電力，激發反應室3内之清洗氣體，使電聚 產生。使反應室3内之氣體維持預定之壓力並藉 9抽吸，而從排氣管8排出。 轧泵 本發明中所使用之清洗氣體係使用氫氟碳氣體、氧氣 與解離性氣體之混合氣體。 氫氟碳氣體可使用 C2HxFy(x=l、2，y=4、5)、c3HxFy ^x 1 2，y~6、7)等飽和低級烴之氫之一部分經氟取 代之lUfcte氣體之1種或2種以上之混合氣體，較佳的氯 鼠石厌氣體可舉例如：C2HFS、C3HF7等。 此等氫氟碳氣體係可容許濃度值高且地球溫暖化係 數小於C2F6之氣體。 氫氟妷氣體與氧氣之混合比率係，以體積比計，相對 於氫氟碳氣體100份，氧氣為4⑽至900份，若未達4㈨ 知，則氫氟妷分子内之碳成分會成為不完全燃燒狀態，而 經由在電漿環境中之反應所生成之具活性的氟原子會不 足。此外，若超過900份，則放電電壓（Vpp)會顯著升 高。 ’、 所明解離性氣體’係指由2個以上之原子組成之分子 且具有化學鍵之氣體。具體的解離性氣體可舉例如： (鍵解離能（C —C): 4.28eV)、c_c4Fs(鍵解離能（c—c): 2.26eV)、NF3(鍵解離能（N—F):2 63eV)等之 1種或2 種以上之混合氣體，其他也可使用Cjs (鍵解離能（c — C) : 4.10eV)、N20 (鍵解離能（N-0) : i.73eV)等。此 321131 8 201002857 等之中，由於化學鍵容易解離，故以具有分子内之鍵解離 能為3eV以下之化學鍵之解離性氣體特佳。 不含在如此之解離性氣體之範圍中之氣體有氬氣、氦 氣、氖氣等稀有氣體(rare gas)。 相對於氫氟碳氣體與氧氣之合計量，如此之解離性氣 體之使用量以體積比計為5至10%。若解離性氣體之比例 在此範圍外，則會無法抑制電弧放電之產生。 清洗處理時之電漿放電條件係例如：高頻電力為3W /cm2至6W/cm2、溫度為300至500°C、壓力為4至 lOTorr、總氣體流量為400至lOOOsccm，但不限定於此範 圍，實際上係由實驗上的嗜試錯誤法(trial-and-error)決定。 在本發明之清洗方法中，清洗用氣體中之氳氟碳氣體 與氧氣在電漿環境中反應而生成具活性的氟原子，此具活 性的氟原子使附著於反應室3及排氣管8之内壁面之由矽 氧化物等組成之固體狀堆積物轉變成四氟化矽等氣體狀化 (. 合物後，從排氣管8排出至系統外。 此時，可認為因共存有解離性氣體，而可藉由較低的 能量生成電漿，且所生成之電漿之高能量成分也少，而使 電漿之電位成為中性（0V)。此外，可預測到放電電壓不 會升高，且自偏壓也不會成為大的負值。 另一方面，可認為若添加過剩的解離性氣體，則電漿 之電子密度會過度降低，為了持續進行電漿放電，而以使 每1個電子之能量提高之方式改變特性。此外，可預測到 放電電壓會升高，且自偏壓會成為大的負值，而會形成不 9 321131 201002857 安定的電漿。 因此，添加適量之解離性氣體，即可抑制放電電壓任 意升高，且自偏壓不會成為大的負值，結果可防止電弧產 生。因此，反應室3内之各種零件不會受損，而不會發生 成膜異常產生等不良情形。 (實施例） 以下，表示包含實施例之具體例。 (習知例） 使用藉由四乙氧基矽烷（TEOS)之矽氧化膜成膜用 之平行平板型電漿裝置（Applied Materials公司製 Precision5000，5忖晶圓），評估藉由做為標準清洗氣體使 用之六氟乙烷與氧氣之混合氣體系清洗反應室之性能。 進行清洗時之狀態評估係在反應室蓋内之RF波導安 裝高壓探針，監測放電電壓（Vpp )與自偏壓（Vdc )。清 洗係在使碎氧化膜成長約800nm後進行。 清洗之條件係如下述。201002857 VI. INSTRUCTIONS: [RELATED APPLICATIONS] This application claims priority based on Japanese Patent Application No. 2008-111377, filed on April 22, 2008 in Japan. [Technical Field] The present invention relates to a method for cleaning a plasma film forming apparatus, and a method for plasma-cleaning a gas containing fluorine after forming a film using a film-forming gas containing ruthenium . 〆 [Prior Art] In the electronic device manufacturing process, there are a large number of steps of forming an insulating film of a tantalum oxide film and a tantalum nitride film. Most of the methods for forming such insulating films use plasma CVD (pECVD). In the same process, as the film formation process proceeds, solid deposits mainly as film-forming components are also accumulated in the reaction chamber and in the exhaust line. Since the solid deposit causes an abnormal film formation state, generation of particles, and clogging of the exhaust line, it is necessary to clean the inside of the reaction chamber and the exhaust line in accordance with the cumulative film thickness and the film formation frequency. For this cleaning method, a dry cleaning in which a solid deposit is chemically changed by an active fluorine atom to a volatile vapor such as antimony tetrafluoride (SiF4) and then removed as an exhaust gas is widely used. In order to generate an active fluorine atom, a gas having a fluorine atom in a molecule is used, and a method of plasma-forming a perfluoro-substituted compound (PFC) of tetrafluoromethane (CFO or hexafluoroethane (c2F6)) is generally used (Non-Patent Document) D. However, these pFC gas systems warm the earth's gases (Non-patent 32131 3 201002857 Document 2). In the semiconductor industry, these global warming substances have been revealed to be based on 1995 until 2010. The goal of reducing the discharge of PFC gas is as a cleaning method for reducing the discharge amount of PFC gas. The applicant has previously applied a so-called replacement gas using a hydrofluorocarbon gas having a hydrogen atom in the molecule to perform plasma treatment. The cleaning method disclosed in the prior invention is a mixed gas composed of a hydrofluorocarbon gas such as tetrafluoroethane or pentafluoroethane, and a mixed gas of a gas containing oxygen such as oxygen as a cleaning gas. And cleaning by plasma treatment. However, when using such an alternative gas, generally, the physical properties of the replacement gas itself, or the substitution gas In the relationship of the mixing ratio of oxygen, the discharge voltage (Vpp) at the time of plasma treatment is increased, or the self bias (Vdc) tends to fluctuate toward the negative side. The discharge voltage is applied to The peak to peak voltage between the positive potential and the negative potential of the high-frequency voltage between the electrodes, and is the voltage required for the plasma discharge. In addition, the self-bias is the discharge voltage. The voltage at the position of 1/2. If the discharge voltage is extremely higher than the conventional conditions, or the self-bias becomes a large negative value, electro-polymerization called arcing is likely to occur at the time of plasma generation. Partial abnormal discharge. In addition to the difficulty in promoting the plasma to support chemical reactions for normal cleaning, the arc will also cause various parts in the reaction chamber to be damaged by 4 321131 201002857, resulting in shortened life or abnormal film formation. Therefore, it is necessary to control the plasma in such a manner that the arc is not generated. The discharge voltage is preferably one having the same value as in the conventional cleaning method, and it is expected that the self-biasing also does not become. The plasma is maintained in a manner of a large negative potential. [Non-Patent Document 1] Mocella, M. t. Mat. Res. Soc. Symp. Proc. 447 (Environment, Safety and Health Issues in IC Production), 29 ( 1997). [Non-Patent Document 2] Ehhalt, D.; Prather, M. Intergovernmental Panel on Climate Change (IPCC), Climate Change 2001: The Scientific Basis. Atmospheric Chemistry and Greenhouse Gases (2001). [Non-Patent Document 3] Japan Electronic Information Technology Industry Association. Report published, "The Results of the 9th World Semiconductor Conference (WSC)" http://semicon.jeita.or.jp/docs/wsc.pdf ( 2005 ). ^ [Summary of the Invention] (Problem to be Solved by the Invention) Therefore, the object of the present invention is to suppress the occurrence of arc discharge when a mixed gas of hydrofluorocarbon gas and oxygen gas is used as a cleaning gas and is cleaned by plasma treatment. The various parts in the reaction chamber are damaged without occurrence of film formation abnormalities and the like. Means for Solving the Problems In order to solve such a problem, the present invention provides a cleaning method for a plasma film forming apparatus which removes deposits accumulated in a reaction chamber of a plasma CVD film forming apparatus 321131 5 201002857 and an exhaust line. a method in which a mixed gas containing a hydrofluorocarbon gas, oxygen and a dissociable gas and a ratio of a dissociable gas of 5 to 10% by volume of a total of hydrofluorocarbon gas and oxygen is used as a cleaning gas for plasma treatment . In the present invention, the "nitrogen carbon gas is preferably a pentafluoroethane gas. Further, the dissociable gas is preferably one or more selected from the group consisting of CF4, C2F6, C3F8, C-C4F8 (cyclic C4F8), NF3, and N20. (Effect of the Invention) According to the present invention, a mixed gas containing a hydrofluorocarbon gas, oxygen gas, and a dissociable gas and having a ratio of a dissociable gas of 5 to 10% by volume of a total of hydrofluorocarbon gas and oxygen is used as a cleaning gas. The gas, while in the plasma treatment, the discharge voltage is almost the same as that of the conventional cleaning gas, and does not rise arbitrarily, and the self-bias voltage does not become a large negative value. Therefore, the occurrence of the local abnormal discharge of the plasma of the arc is suppressed, and the various parts in the reaction chamber are not damaged, and the film formation abnormality or the like does not occur. In addition, the amount of global warming substances is also reduced. [Embodiment] Fig. 1 is a view showing an example of a plasma CVD film forming apparatus for carrying out the cleaning method of the present invention. This plasma CVD film forming apparatus includes a plasma generating means 2 such as a parallel plate type in which high-frequency power is applied from a high-frequency power source 1 to generate plasma, and is basically constituted by a plasma environment. A reaction chamber 3 for forming a film such as ruthenium oxide 6 321131 201002857 is formed on the substrate, a gas for film formation is introduced into the raw material gas introduction pipe 4 in the reaction chamber 3, and a mouse carbon gas constituting the cleaning gas is supplied into the reaction chamber 3. The first introduction pipe 5, the second introduction pipe 6 for supplying oxygen constituting the cleaning gas into the reaction chamber 3, and the third introduction pipe 7 for supplying the dissociative gas constituting the cleaning gas into the reaction chamber 3 And an exhaust pipe 8 having an exhaust pump 9 that discharges the gas in the reaction chamber 3. The plasma generating means 2 includes a shower head 21 through which a film forming gas and a cleaning gas flow out, and a susceptor 22 on which a substrate is placed, and is formed between the shower head 21 and the susceptor 22 from the high frequency power source 1 The state in which high frequency power is applied. The material gas introduction pipe 4, the first introduction pipe 5, the second introduction pipe 6, and the third introduction pipe 7 are electrically connected to the shower head 21, and are formed such that the film forming gas and the cleaning gas flow out from the shower head 21 toward the substrate. When the film formation is performed by the film forming apparatus, a substrate such as a substrate is placed on the susceptor 22 in the reaction chamber 3, and tetraethoxy decane, oxygen, nitrogen, ammonia, or the like is contained from the material gas introduction pipe 4. After the raw material gas is introduced into the reaction chamber 3, it flows out from the shower head 21, and the plasma generating means 2 is activated, and a film such as an oxide film is formed on the substrate by plasma CVD reaction. The gas in the reaction chamber 3 is discharged from the exhaust pipe 8 by suction by the exhaust pump 9. When the inside of the reaction chamber 3 and the exhaust pipe 8 of the plasma CVD film forming apparatus is cleaned, a predetermined amount of hydrofluorocarbon gas is supplied from the first introduction pipe 5 to the reaction chamber 3 via the mass flow meter 10, from the first The introduction pipe 6 feeds a predetermined amount of oxygen into the reaction chamber 3 via the mass flow meter 11, and feeds the dissociable gas from the third introduction pipe 7 via the mass flow meter 12. 7 321131 201002857 ~ Then two between the shower head 21 and the pedestal 22 from the high-frequency power supply [applying pre-charged south frequency power, the cleaning gas in the reaction chamber 3 is excited to generate electricity. The gas in the reaction chamber 3 is maintained at a predetermined pressure and sucked from the exhaust pipe 8 by suction. Rolling pump The cleaning gas system used in the present invention uses a hydrofluorocarbon gas, a mixed gas of oxygen and a dissociative gas. As the hydrofluorocarbon gas, one type of lUfcte gas in which one part of hydrogen of a saturated lower hydrocarbon such as C2HxFy (x=l, 2, y=4, 5), c3HxFy^x 1 2, y~6, 7) is substituted by fluorine can be used. For example, C2HFS, C3HF7, etc. may be mentioned as a mixed gas of two or more types. These HFC systems allow for gases with high concentration values and a global warming coefficient less than C2F6. The mixing ratio of the hydrofluorocarbon gas to the oxygen gas is 4 (10) to 900 parts by volume with respect to 100 parts of the hydrofluorocarbon gas, and if it is less than 4 (nine), the carbon component in the hydrofluorocarbon molecule will become The complete combustion state, while the active fluorine atoms generated by the reaction in the plasma environment will be insufficient. In addition, if it exceeds 900 parts, the discharge voltage (Vpp) will rise remarkably. The term "dissociated gas" means a gas having a chemical bond composed of a molecule composed of two or more atoms. Specific dissociable gases include, for example: (bond dissociation energy (C-C): 4.28 eV), c_c4Fs (bond dissociation energy (c-c): 2.26 eV), NF3 (bond dissociation energy (N-F): 2 For a mixture of one or more of 63 eV), Cjs (bond dissociation energy (c - C): 4.10 eV), N20 (bond dissociation energy (N-0): i.73 eV), and the like may be used. In the case of 321131 8 201002857, etc., since the chemical bond is easily dissociated, it is particularly preferable to use a dissociable gas having a bond bond having an intramolecular bond dissociation energy of 3 eV or less. The gas not contained in the range of such dissociative gas is a rare gas such as argon gas, helium gas or neon gas. The dissociable gas is used in an amount of 5 to 10% by volume based on the total amount of the hydrofluorocarbon gas and the oxygen. If the ratio of the dissociative gas is outside this range, the occurrence of arc discharge cannot be suppressed. The plasma discharge conditions at the time of the cleaning treatment are, for example, high-frequency power of 3 W /cm 2 to 6 W/cm 2 , temperature of 300 to 500 ° C, pressure of 4 to 10 Torr, and total gas flow rate of 400 to 1000 sccm, but are not limited thereto. The range is actually determined by the experimental trial-and-error method. In the cleaning method of the present invention, the fluorocarbon gas in the cleaning gas reacts with oxygen in a plasma environment to form an active fluorine atom, and the active fluorine atom adheres to the reaction chamber 3 and the exhaust pipe 8. The solid deposit composed of ruthenium oxide or the like on the inner wall surface is converted into a gasification such as ruthenium tetrafluoride (the compound is discharged from the exhaust pipe 8 to the outside of the system. At this time, it is considered that there is dissociation due to coexistence. a gas, which can generate plasma by a lower energy, and the generated plasma has a lower energy content, and the potential of the plasma becomes neutral (0 V). In addition, it is predicted that the discharge voltage will not be When it is raised, the self-bias voltage does not become a large negative value. On the other hand, it is considered that if an excessive dissociation gas is added, the electron density of the plasma is excessively lowered, and in order to continue the plasma discharge, The energy is changed every one electron to change the characteristics. In addition, it is predicted that the discharge voltage will rise, and the self-bias voltage will become a large negative value, and a plasma of no stability will be formed. Therefore, an appropriate amount is added. Dissociated gas, you can The suppression discharge voltage is arbitrarily increased, and the self-bias voltage does not become a large negative value, and as a result, arc generation can be prevented. Therefore, various components in the reaction chamber 3 are not damaged, and no abnormality such as film formation abnormality occurs. (Examples) Hereinafter, specific examples of the examples are shown. (Conventional Example) A parallel plate type plasma device (Applied Materials Co., Ltd.) for forming a film of a ruthenium oxide film by tetraethoxy decane (TEOS) Precision5000, 5忖 wafer), evaluates the performance of the chamber by cleaning the mixture of hexafluoroethane and oxygen used as a standard cleaning gas. The state of the evaluation during cleaning is the RF waveguide installation in the chamber cover. The high voltage probe monitors the discharge voltage (Vpp) and the self-bias voltage (Vdc). The cleaning is performed after the crushed oxide film is grown to about 800 nm. The cleaning conditions are as follows.
高頻施加電壓：750W 反應室内壓力（高壓清洗）：3.5torr 清洗時間：70sec 基板溫度：400°C 氣體流量：六氟乙烧（C2F6) 500sccm +氧氣600sccm 電極間距離：999milsHigh-frequency applied voltage: 750W Reaction chamber pressure (high pressure cleaning): 3.5torr Cleaning time: 70sec Substrate temperature: 400°C Gas flow rate: hexafluoroethane (C2F6) 500sccm + oxygen 600sccm Distance between electrodes: 999mils
進行清洗時測得之Vpp與Vdc之結果如第2圖所示。 Vpp在大約500V左右變動，此外，Vdc在一2.5V至一0.5V 10 321131 201002857 變動。 (實施例1) 將由做為氫氟碳氣體之c2HF5、〇2與做為解離性氣體 之Cf6組成之混合氣體做為清洗用氣體使用，進行Vpp 與Vdc之狀態測定。 、 使QHF5與〇2之總流量圉定為6〇〇sccm、RF電源固 定為750W、電極間距離固定為999mils，並使c2HF5之濃 度（〔C2HF5) /〔C2HF5 + 〇2))在 1〇% 至 2〇% 變動、壓 力在3T〇rr至5ΤΟΠ*變動、解離性氣體之濃度（〔解離性氣 體）/〔 C2HF5+〇2))在〇至1〇%變動，依實驗設計法分 析各因子之條件相依性。結果如第3圖所示。 、弟3圖之圖表係’縱軸之上段為放電電壓Vpp，下段 為自偏壓’㈣之左側為氫氟碳氣體之濃度（％ )、中間為 反^内之壓力右側為解離性氣體之濃度（％ )， ^丁氫氟竣氣體浪度、壓力及解離性氣體濃度之變化會 對=電電壓與自偏壓造成影響。第4圖至第6圖之圖表也 产為〇。者第3圖至第6圖之圖表之橫軸之解離性氣體濃 :中放電電壓及自偏壓之值係上述之由本發明人 所犍出之前案發明者。 由镇^越回、WC成為越大的負值，則電孤風險越升高。 位、之分析結果得知’VPP—且·朝正值變大之 1 木加8.2%之解離性氣體之〇2匕之條件。 4 Vpp為543V、Vdc為+ 〇 lv，相較於以習知之 321131 11 201002857 ^氣體做為清洗用氣體之清洗方法，為同等之結果 =加氣體之流量少或多於此之條件，則任—者皆 較咼，Vdc為較低的值。 PP為 (實施例2 ) 離性施例1同樣的方法，進行當使用做為解 離^體時之狀。分析結果如第4 7 條件。 〃牛也為電弧風險最小的 此二夺’ VPP為544V、Vdc為+ 1抑，相較 =^體做為清洗用氣體之清洗方法，為之 (貫施例3 ) 依與實施例！同樣的方法，進行當使用 性氣體時之測定。分析結果如第5圖所示時，、天為解^ 士 &之卵3之條件也為電弧風險最小的條件。The results of Vpp and Vdc measured during cleaning are shown in Fig. 2. Vpp varies around 500V. In addition, Vdc varies from 2.5V to 0.5V 10 321131 201002857. (Example 1) A mixed gas composed of c2HF5 and cesium 2 as a hydrofluorocarbon gas and Cf6 as a dissociable gas was used as a cleaning gas, and the state of Vpp and Vdc was measured. The total flow rate of QHF5 and 〇2 is set to 6〇〇sccm, the RF power supply is fixed at 750W, the distance between electrodes is fixed at 999mils, and the concentration of c2HF5 ([C2HF5) / [C2HF5 + 〇2)) is at 1〇. % to 2〇% change, pressure change from 3T〇rr to 5ΤΟΠ*, concentration of dissociative gas ([dissociable gas)/[C2HF5+〇2)) varies from 〇 to 1〇%, and each factor is analyzed by experimental design method Conditional dependence. The result is shown in Figure 3. The diagram of the brother 3 is the discharge voltage Vpp in the upper part of the vertical axis, the self-bias in the lower stage, the concentration (%) of the hydrofluorocarbon gas on the left side of the (four), and the dissociation gas on the right side of the pressure in the middle. The concentration (%), the change of the hydrogen fluoride gas pulse, the pressure and the dissociated gas concentration will affect the electric voltage and the self-bias voltage. The graphs in Figures 4 through 6 are also produced as 〇. The dissociative gas concentration on the horizontal axis of the graphs in Figs. 3 to 6 is the inventor of the present invention by the present inventors. The more the negative value of the WC becomes, the higher the risk of electric isolation is. As a result of the analysis of the position, it was found that the condition of 'VPP-and the positive value becomes larger and the condition of the 8.2% dissociative gas is increased. 4 Vpp is 543V, Vdc is + 〇lv, compared with the conventional cleaning method of 321131 11 201002857 ^ gas as the cleaning gas, the same result = less or more than the gas flow rate, then - All are awkward, Vdc is a lower value. PP was (Example 2) The same method as in the case of the detachment Example 1 was carried out when it was used as a dissociation body. The results of the analysis are as in the 4th 7th condition. The yak is also the one with the least risk of arcing. The VPP is 544V and the Vdc is +1. Compared with the body, it is used as a cleaning method for cleaning gas. (Example 3) Depending on the embodiment! In the same manner, the measurement is performed when a gas is used. When the results of the analysis are as shown in Fig. 5, the conditions for the egg 3 of the solution and the egg are also the conditions for the minimum risk of arcing.
c2J；；V；r 489V'VdC^4-7V'^-«tL 2 ό礼體做為清洗用氣體之 低的結果。 次仍為電弧放電風險 (比較例1 ) 氟碳Γί實施=同樣的方法’進行當添加C-CA取代氫 結果3二性氣體之阳時之測定。分析c2J;;V;r 489V'VdC^4-7V'^-«tL 2 The ritual body is a low result of the cleaning gas. The risk of arcing was still the same (Comparative Example 1) Fluorocarbon Γ = = the same method' The measurement was carried out when C-CA was substituted for hydrogen and 3 bismuth gas was used. analysis
此時，添加4.7%之解離性氣體NF 風險最小的條件。惟，此時，隨著解離性= 有成為大的备信夕心 虱體之流1增加， 負值之傾肖，而無法辨識解離性氣體之效 321131 12 201002857 果。 (比較例2) 依與實施例1同樣的方法 羊L軋興小 體， 〜々広，Μ混合u2_hf5、氧氣 之氣氣（He)而成之混合氣體做為清洗用氣 進行實施清洗時之測定。 測疋壓力固定為5Torr。測定結果如表1所示。 、由表1之結果得知，當使用不具解離性之取時，V沖 有增加的傾而，a A > .. 添加濃度（％ ) --- 一 .·▼ 7，、、 放電電壓（V) CP豕、牙玉Ij 自偏壓（V) 0 588 —1.3 5 590 -1.4 【圖式簡單說明 第1圖係表示本發明之清洗方法中所使用之電漿處理 裝置之例子之示意構成圖。 第2圖係表示習知例之結果圖表。 第3圖係表示實施例1之結果圖表。 弟4圖係表不實施例2之結果圖表。 第5圖係表示實施例3之結果圖表。 第6圖係表示比較例1之結果圖表。 【主要元件符號說明】 1 高頻電源 2 電漿產生手段 3 反應室 321131 13 201002857 4 原料氣體導入管 5 第1導入管 6 第2導入管 7 第3導入管 8 排氣管 9 排氣泵 10,11,12 質量流量計 21 蓮蓬頭 22 基座 14 321131At this time, the condition that the 4.7% dissociative gas NF has the least risk is added. However, at this time, with the dissociation = there is a large reserve letter, the flow of the body is increased, the negative value is dim, and the effect of the dissociative gas cannot be recognized. 321131 12 201002857 (Comparative Example 2) In the same manner as in the first embodiment, the mixed gas obtained by mixing the small body, the 々広, the Μ mixed with the u2_hf5, and the oxygen gas (He) was used as the cleaning gas. Determination. The test pressure is fixed at 5 Torr. The measurement results are shown in Table 1. From the results of Table 1, it is known that when using the dissociation, the V-punch has an increased inclination, a A > .. Adding the concentration (%) --- a.·▼ 7,,, discharge voltage (V) CP豕, jade Ij self-bias (V) 0 588 —1.3 5 590 -1.4 [Simplified illustration of the drawings Fig. 1 is a schematic view showing an example of a plasma processing apparatus used in the cleaning method of the present invention. Make up the picture. Fig. 2 is a graph showing the results of a conventional example. Fig. 3 is a graph showing the results of Example 1. Figure 4 shows the result chart of Example 2. Fig. 5 is a graph showing the results of Example 3. Fig. 6 is a graph showing the results of Comparative Example 1. [Explanation of main component symbols] 1 High-frequency power supply 2 Plasma generation means 3 Reaction chamber 321131 13 201002857 4 Raw material gas introduction pipe 5 First introduction pipe 6 Second introduction pipe 7 Third introduction pipe 8 Exhaust pipe 9 Exhaust pump 10 ,11,12 mass flow meter 21 shower head 22 base 14 321131