200822216 九、發明說明 【發明所屬之技術領域】 本發明是關於被配置在用以對被處理基板施予電漿蝕 刻處理等之電漿處理之電漿處理裝置上之聚焦環及電漿處 理裝置。 【先前技術】 以往電漿蝕刻裝置等之電漿處理裝置多使用於例如半 導體裝置之微細電路之製造工程等。 作爲如此之電漿處理裝置，所知的有將半導體晶圓等 之被處理基板配置在設置於處理腔室內之載置台，在該載 置台和屬於對向電極之上部電極之間施加高頻電力使產生 電漿而執行處理之所謂平行平板電極型之電漿處理裝置。 再者，在如此之電漿處理裝置中，配置以包圍被處理 基板之周圍的方式，配置形成環狀之聚焦環使處理之面內 均勻性提升。並且，由環狀之導電性構件和配置在該環狀 之導電性構件之下部之環狀絕緣性構件構成聚焦環，依據 形成自被處理基板朝向環狀導電性構件之電場，防止電漿 朝向被處理基板之邊緣部背面側（例如參照專利文獻1 ) 迴避，可以降低朝該部位產生電位。 [專利文獻1]日本特開2005-2773 69號公報 【發明內容】 [發明所欲解決之課題] -4 - 200822216 於上述以往之技術中，由環狀之導電性構件，和配置 於該環狀之導電性構件下部之環狀絕緣性構件構成聚焦環 之技術，是關於對向電極中對上部電極供給用以產生電漿 之頻率更高之高頻率電力，對下部電極（載置台）施加用 以取出離子之頻率更低之偏壓用高頻電力之類型的電漿處 理裝置。即是，於該以往技術時，因電漿發生是藉由被施 加於上述電極之高頻而執行，故藉由調整被載置在下部電 極上之聚焦環，控制主要對被處理基板邊緣部取出離子之 狀態（離子取出角度或朝背面迴避）。 對此，將上部電極設爲接地電位，藉由施加於下部電 極（載置台）之高頻電力而發生電漿之類型的電漿處理裝 置則有以往下述般之課題。 即是，例如於藉由電漿蝕刻處理電漿蝕刻被處理基板 之時，即使在使用相同聚焦環及電漿處理裝置之時，藉由 蝕刻氣體之種類等，在被處理基板之邊緣部則有蝕刻率變 高時，或是在被處理基板之邊緣部蝕刻率降低之情形等， 屬於鈾刻處理之面內均勻性惡化之課題。尤其，使用不產 生沉積（堆積物）之蝕刻氣體時，藉由調整沉積量等之製 程，因無法調整面內均勻性，故產生必須藉由硬體之調整 提升蝕刻處理之面內均勻性的必要性。 本發明是鑒於上述以往之情形所創作出，其目的爲提 供比起以往可以提升電漿處理之面內均勻性之聚焦環及電 漿處理裝置。 200822216 [用以解決課題之手段] 申請專利範圍第1項所記載之聚焦環，是在對載置被 處理基板之載置台施加高頻電力，使與該載置台對向而被 設置成爲接地電位之上部電極之間產生電漿，對上述被處 理基板施予電漿處理之電漿處理裝置之上述載置台，載置 成包圍上述被處理基板之周圍，其特徵爲：具備 由導電性材料所構成之第1環狀構件，在內側邊緣部 具有比被載置在上述載置台之上述被處理基板下面更低位 置之段部，該段部是構成延伸於上述被處理基板之周邊部 下側；和 由絕緣性材料所構成之第2環狀構件’如介於上述第 1環狀構件和上述載置台之間地被配置在上述第1環狀構 件之下側。 申請專利範圍第2項之聚焦環是如申請專利範圍第1 項所記載之聚焦環中’上述第2環狀構件是由氧化錫陶瓷 所構成。 申請專利範圍第3項之聚焦環是如申請專利範圍第1 或2項所記載之聚焦環，其中，上述第1環狀構件爲矽或 碳或是S i C。 申請專利範圍第4項之聚焦環申請專利範圍第1至3 項中之任一項所記載之聚焦環’其中’上述弟1 狀構件 是比上述段部更外側部份之上面’爲比被載置於上述載置 台之上述被處理基板之表面更高位置之平坦部。 申請專利範圍第5項之電漿處理裝置’其特徵爲：具 -6 - 200822216 備處理腔室，用以收容被處理基板而施予特定電漿處理； 載置台，被設置在上述處理腔室內，載置上述被處理基板 ;高頻電源，將高頻電力供給至上述載置台而使電漿產生 ;上部電極，與上述載置台相向而被設置，被設爲接地電 位；和聚焦環，屬於以包圍上述被處理基板之周圍的方式 被載置在上述載置台之聚焦環，具備：由導電性材料所構 成之第1環狀構件，在內側邊緣部具有比被載置在上述載 置台之上述被處理基板下面更低位置之段部，該段部是構 成延伸於上述被處理基板之周邊部下側；和由絕緣性材料 所構成之第2環狀構件，如介存於上述第1環狀構件和上 述載置台之間被配置在上述第1環狀構件之下側。 申請專利範圍第6項之電漿處理裝置是如申請專利範 圍第5項所記載之電漿處理裝置中，上述第2環狀構件是 由氧化鋁陶瓷所構成。 申請專利範圍第7項之電漿處理裝置是如申請專利範 圍第5或6項所記載之電漿處理裝置中，上述第1環狀構 件爲矽或碳或是SiC。 申請專利範圍第8項之電漿處理裝置是如申請專利範 圍第5至7項中之任一項所記載之電漿處理裝置中，上述 第1環狀構件是比上述段部更外側部份之上面，爲比被載 置於上述載置台之上述被處理基板之表面更高位置之平坦 部。 [發明效果] 200822216 若藉由本發明，則可以提供比起以往可以提 理之面內均勻性之聚焦環及電漿處理裝置。 【實施方式】 以下，針對本發明之實施形態參照圖面予以 1圖是表示當作本實施形態所涉及之電漿裝置之 裝置之構成。電漿裝置是構成氣密，具有成爲電 位之處理腔室1。該處理腔室1爲圓筒狀，例如 成。在處理腔室1內設置有略水平載置屬於被處 半導體體晶圓30之載置台2。該載置台2爲兼 極，例如由鋁等之導電性材料所構成，經絕緣板 導體支撐台4。再者，在載置台2上之外圍部分 導體晶圓3 0之周圍的方式，設置有形成環狀之 。聚焦環5是由導電性材料所構成之第1環狀| 和被配置在該地1環狀構件5a之下側的由絕緣 構成之第2環狀構件5b。針對該聚焦環5之詳 後述。 在載置台2經匹配箱1 1連接有RF電源1 0。 源1〇將特定頻率（例如13.56MHz )之高頻電力 置台另外，與載置台2對向互相平行設置有t ’該噴淋頭1 6接地電位。因此，該些噴淋頭16 2是當作一對對向電極（上部電極和下部電極） 能。 在載置台2之上面設置有用以靜電吸附半 升電漿處 說明。第 電漿鈾刻 性接地電 由鋁等構 理基板之 作下部電 3支撐於 以包圍半 聚焦環5 _ 件 5a， 性材料所 細構成於 自RF電 供給置載 賁淋頭16 和載置台 而發揮功 導體晶圓 -8- 200822216 30之靜電夾6。該靜電夾6是使電極6a介於絕緣體6b之 間而構成，於電極6a連接有直流電源1 2。然後’藉由直 流電壓自直流電源1 2施加至電極6a，構成以庫倫力等吸 附半導體晶圓3 0。 在載置台2之內部形成有無圖示之冷煤流路，其中藉 由使適當冷煤循環，可將半導體晶圓3 0控制成特定溫度 。再者，於聚焦環5之外側設置有排氣環1 3。排氣環1 3 通過支撐台4而與處理腔室1導通。 在處理腔室1之天壁部份，於設置成與載置台2對向 之噴淋頭16之下面設置有多數氣體噴出孔18，並且’在 該上部設置有氣體導入部16a。然後，在該內部形成有空 間17。在氣體導入部16a連接有氣體供給配管15a，該氣 體供給配管1 5a之另一端連接有供給電漿鈾刻用之處理氣 體（蝕刻氣體）之處理氣體供給系統1 5。 自處理氣體系統1 5所供給之處理氣體是經氣體供給 配管15a、氣體導入部16a而移動至噴淋頭16內部之空 間1 7，自氣體噴出孔1 8朝向半導體晶圓3 0而吐出。自 處理氣體供給系1 5所供給之處理氣體之例，爲例如 n2/o2之混合氣體，N2/H2之混合氣體等。 在處理腔室1之下部形成有排氣埠1 9，在該排氣埠 1 9連接有排氣系統20。然後，可以藉由使設置在排氣系 統20之真空泵動作，使處理腔室1內減壓至特定的真空 度。另外，在處理腔室1之側壁設置有開關晶圓3 0之搬 入出口之閘閥24。 -9 - 200822216 另外，在處理腔室1之周圍同心狀設置有環磁石21 ，使磁場波及至載置台2和噴淋頭1 6之間。該環磁石2 1 藉由無圖示之馬達等之旋轉手段可旋轉。 上述構成之電漿蝕刻裝置是藉由控制部60該動作統 籌被控制。在該控制部60具備CPU，設置有控制電漿蝕 刻裝置之各部的製程控制器6 1、使用介面62和記憶部63 〇 使用者介面62是由工程者爲了管理電漿飩刻裝置而 執行指令之輸入操作之鍵盤，或將電漿鈾刻裝置之運轉狀 況可視化而予以顯示之顯示器等所構成。 在記憶部63儲存有用以製程控制器6 1之控制實現在 電漿蝕刻裝置中所實行之各種處理的庫正程式（軟體）或 記憶有處理條件資料等之處理程式。然後，因應所需，自 記憶部63叫出來自使用者介面62之指示而使製程控制器 6 1實行，依此在製程控制器6 1之控制下執行電漿裝置 之所欲處理。再者，控制程式或處理條件資料等之處理程 式可利用儲存於可在電腦讀取之電腦記憶媒體（例如硬碟 、CD、軟碟、半導體記憶體等）等之狀態者，或是亦可 自其他裝置例如經專用回路隨時傳送而在線上利用。 接著，針對是上述構成之電漿裝置中，電漿蝕刻半導 體晶圓3 0之程序予以說明。首先，打開閘閥24，半導體 晶圓3 0藉由無圖示之搬運機器手臂等，經無圖示之負載 鎖定室而被搬入至處理腔室1內，被載置於載置台2上， 之後，使搬運機器手臂退避至處理腔室1外，關閉閘閥 -10- 200822216 24。然後，藉由排氣系20之真空泵經排氣埠19而排氣處 理腔室1內。 處理腔室1內成爲特定真空度之後，特定處理氣體（ 鈾刻氣體）導入至自處理氣體供給系統丨5導入至處理腔 室1’處理腔室1內被保持特定壓力，例如8.0Pa，在該 狀態中，從RF電源1 0供給頻率爲例如13 ·56ΜΗζ，功率 爲例如100〜5 000W之高頻電力至載置台2。此時，從直 流電源1 2施加特定直流電壓至靜電夾6之電極6a，半導 體晶圓3 0藉由庫倫力而吸附。 此時，如上述搬，藉由對屬於下部電極之載置台2施 加高頻電力，在屬於上部電極之噴淋頭1 6和屬於下部電 極之載置台2之間形成電場。另外，由於藉由環磁石2 1 在處理腔室1之上部1 a形成水平磁場，故在存在半導體 晶圓3 0之處理空間藉由電子之漂移，產生磁控管放電， 藉由依此所形成之處理氣體之電漿，鈾刻處理半導體晶圓 30 ° 然後，當完成特定蝕刻處理時，停止高頻電力之供給 及處理氣體之供給，以與上述程序相反之程序，自處理腔 室1內搬出半導體晶圓30。 接著，參照第2圖說明聚焦環5之構成。第2圖爲模 式性表示載置聚焦環5之載置台2之部份的重要剖面構成 ，同圖中，雖然爲了容易了解各構成構件之形狀，在各構 成構件間設置間隔，但是實際上該些構件彼此（除了半導 體晶圓3 0和聚焦環5之間外）爲抵接。如同圖所示般， -11 - 200822216 聚焦環5是由第1環狀構件5 a，和配置在 件5a下側之第2環狀構件5b所構成。 第1環狀構件5a是由矽、碳、SiC等 所構成，形成環狀。在該第1環狀構件5 a 形成有比載置在載置台2之半導體晶圓30 置之段部5 0 ’該段部5 0被構成延伸於半導 邊緣部下側。再者，比段部5 0外側部份是 平坦部5 1。該平坦部5 1是構成比段部5 0 第1環狀構件5 a之使用開始前之初期狀態 部51之上面比載置在載置台2之半導體晶U 高位置。並且，該第1環狀構件5 a之平坦姜 曬於電漿，漸漸消耗，該高度逐漸變低。在 ，第1環狀構件5a之厚度（第2圖中所斥 米左右，例如4mm，段部50之厚度（第2 )爲例如2 · 5 mm，段部5 0之徑方向長度（ 之e )爲例如2mm左右。 第2環狀構件5b是由例如氧化鋁陶瓷 緣性材料所構成，形成環狀。該第2環狀榍 存於第1環狀構件5 a和載置台2之間被配 構件5a之下側。即是，第2環狀構件5b被 構件5a直接載置在載置台2上’本實施形 有第1環狀構件5a之徑方向長度（第2匱 和相同徑方向長度（第2圖中所不之b)。 狀構件5b之厚度（第2圖中所不之Ο ’ 該第1環狀構 之導電性材料 之內側邊緣部 之下面更低位 【體晶圓3 0之 上面爲平坦之 高，至少在該 中，構成平坦 B 3 0之比面更 形5 1是藉由曝 本實施形態中 :之d )爲數毫 圖中所示之c 第2圖中所示 、石英等之絕 I件5 b是如介 置在第1環狀 構成第1環狀 態中，構成具 丨所示之a )， 再者，第2環 設爲數毫米左 -12- 200822216 右，例如設爲3mm。並且，在第2圖中，40爲由石英所 構成之外殻，4 1爲由石英等所構成之絕緣體， 在本實施形態中，聚焦環5設爲上述構成是根據以下 之理由。即是，對載置台2 (下部電極）施加高頻電力， 於設爲接地電位之噴淋頭1 6 (上部電極）之間產生電漿 之類型之電漿鈾刻裝置時，藉由使用上述構成之聚焦環5 ，可以比起以往更降低形成在聚焦環5之上部空間之電漿 強度（密度）。依此，可以使電漿集中於被載置於該部份 之電漿強度（密度），並且可以設置與形成在聚焦環5上 部之空間之電漿之相對性之強度（密度）之差。其結果， 可以提高半導體晶圓3 0中之全體性之蝕刻率，並且可以 抑制發生增加或減少半導體晶圓3 0之邊緣部中之蝕刻率 ，並可以提升電漿蝕刻處理之面內均勻性。並且，因使形 成在半導體晶圓3 0之上部空間之電漿，和形成在聚焦環 5之上部空間的電漿之境界部份中之電漿之變化平穩，故 如第2圖所示般，第1環狀構件5a及第2環狀構件5b任 一者構成延伸於半導體晶圓3 0之邊緣部下側。 實施例1是使用上述構成聚焦環5，利用以下之條件 執行有機系光阻罩幕之電漿蝕刻。 餓刻氣體：N2/〇2=200/22sccm 壓力：2.26Pa ( 1 7 mTorr )200822216 IX. DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a focus ring and a plasma processing apparatus which are disposed on a plasma processing apparatus for applying plasma treatment such as plasma etching treatment to a substrate to be processed. . [Prior Art] Conventionally, a plasma processing apparatus such as a plasma etching apparatus is often used in a manufacturing process of a microcircuit such as a semiconductor device. As such a plasma processing apparatus, it is known that a substrate to be processed such as a semiconductor wafer is placed on a mounting table provided in a processing chamber, and high frequency power is applied between the mounting table and an electrode corresponding to an upper electrode of the counter electrode. A plasma processing apparatus of a so-called parallel plate electrode type in which plasma is generated to perform processing. Further, in such a plasma processing apparatus, a ring-shaped focus ring is disposed so as to surround the periphery of the substrate to be processed, and the in-plane uniformity of the treatment is improved. Further, the annular conductive member and the annular insulating member disposed under the annular conductive member constitute a focus ring, and the plasma is prevented from being oriented in accordance with an electric field formed from the substrate to be processed toward the annular conductive member. The back side of the edge portion of the substrate to be processed (for example, see Patent Document 1) can be avoided, and the potential generated in the portion can be reduced. [Patent Document 1] Japanese Laid-Open Patent Publication No. 2005-2773 No. PCT Publication No. 2005-2773, the disclosure of which is hereby incorporated by reference. The technique of forming a focus ring by the annular insulating member in the lower portion of the conductive member is to apply a high-frequency electric power having a higher frequency for generating plasma to the upper electrode in the counter electrode, and apply the lower electrode (mounting table) A plasma processing apparatus of a type that uses a high-frequency power for biasing to extract ions at a lower frequency. That is, in the prior art, since plasma generation is performed by the high frequency applied to the electrode, the edge of the substrate to be processed is mainly controlled by adjusting the focus ring placed on the lower electrode. Remove the state of the ions (ion extraction angle or avoiding toward the back). On the other hand, the plasma processing apparatus of the type in which the upper electrode is set to the ground potential and the plasma is applied by the high-frequency power applied to the lower electrode (mounting stage) has the following problems. That is, for example, when the substrate to be processed is plasma-etched by plasma etching, even when the same focus ring and the plasma processing apparatus are used, the type of the etching gas or the like is applied to the edge portion of the substrate to be processed. When the etching rate is high, or when the etching rate is lowered at the edge portion of the substrate to be processed, the in-plane uniformity of the uranium engraving treatment is deteriorated. In particular, when an etching gas which does not generate deposits (deposits) is used, since the in-plane uniformity cannot be adjusted by adjusting the deposition amount or the like, it is necessary to enhance the in-plane uniformity of the etching treatment by the adjustment of the hard body. necessity. The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to provide a focus ring and a plasma processing apparatus which can improve the in-plane uniformity of plasma processing compared with the prior art. 200822216 [Means for Solving the Problem] The focus ring described in the first aspect of the patent application is that high-frequency power is applied to the mounting table on which the substrate to be processed is placed, and is placed at the ground potential in opposition to the mounting table. A plasma is generated between the upper electrodes, and the mounting table of the plasma processing apparatus that applies the plasma treatment to the substrate to be processed is placed around the substrate to be processed, and is characterized by being provided with a conductive material. The first annular member is configured to have a lower portion on the inner edge portion than a lower surface of the substrate to be processed placed on the mounting table, and the segment portion is configured to extend below the peripheral portion of the substrate to be processed; The second annular member ' composed of an insulating material is disposed between the first annular member and the mounting table on the lower side of the first annular member. The focus ring of the second application of the patent application is in the focus ring described in the first paragraph of the patent application. The second annular member is made of tin oxide ceramic. The focus ring of claim 3 is the focus ring as described in claim 1 or 2, wherein the first ring member is tantalum or carbon or S i C. The focus ring of any one of claims 1 to 3 of the patent application scope of claim 4, wherein the above-mentioned 1st member is the upper side of the outer portion of the segment a flat portion placed at a higher position on the surface of the substrate to be processed on the mounting table. The plasma processing apparatus of claim 5 is characterized in that: -6 - 200822216 preparation processing chamber for accommodating a substrate to be processed for a specific plasma treatment; and a mounting table disposed in the processing chamber a substrate to be processed, a high-frequency power source for supplying high-frequency power to the mounting table to generate plasma, and an upper electrode disposed opposite to the mounting table to be grounded; and a focus ring a focus ring that is placed on the mounting table so as to surround the periphery of the substrate to be processed, and includes a first annular member made of a conductive material, and has an inner edge portion that is placed on the mounting table. a segment at a lower position on the lower surface of the substrate to be processed, wherein the segment is formed on a lower side of a peripheral portion extending from the substrate to be processed; and a second annular member composed of an insulating material is deposited in the first ring The member between the member and the mounting table is disposed below the first annular member. The plasma processing apparatus according to claim 5, wherein the second annular member is made of alumina ceramics. The plasma processing apparatus according to the seventh aspect of the invention, wherein the first annular member is tantalum or carbon or SiC. The plasma processing apparatus according to any one of claims 5 to 7, wherein the first annular member is a lower outer portion than the segment. The upper surface is a flat portion higher than the surface of the substrate to be processed placed on the mounting table. [Effect of the Invention] 200822216 According to the present invention, it is possible to provide a focus ring and a plasma processing apparatus which are comparable to the in-plane uniformity which can be conventionally evaluated. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a view showing a configuration of a device as a plasma device according to the present embodiment. The plasma device is constructed to be airtight and has a processing chamber 1 that becomes an electric potential. The processing chamber 1 is cylindrical, for example. A mounting table 2 belonging to the semiconductor wafer 30 to be placed is placed horizontally in the processing chamber 1. The mounting table 2 is a bipolar electrode, and is made of, for example, a conductive material such as aluminum, and is supported by the insulating plate conductor 4 . Further, a form of a ring is formed on the periphery of the conductor wafer 30 on the peripheral portion of the mounting table 2. The focus ring 5 is a first ring-shaped body made of a conductive material, and a second ring-shaped member 5b made of an insulating material disposed on the lower side of the ring-shaped member 5a. The details of the focus ring 5 will be described later. The RF power source 10 is connected to the mounting table 2 via the matching box 11. The source 1A places a high-frequency power of a specific frequency (for example, 13.56 MHz), and is disposed in parallel with the mounting table 2 so that the shower head 16 has a ground potential. Therefore, the shower heads 16 2 function as a pair of counter electrodes (upper electrode and lower electrode). A description is given on the upper surface of the mounting table 2 to electrostatically adsorb the half-liter plasma. The first plasma uranium grounding electric power is supported by a lower electric layer 3 of a structural substrate such as aluminum to surround the semi-focus ring 5 _ piece 5a, and the material is finely formed on the self-RF power supply and the shower head 16 and the mounting table. The electrostatic chuck 6 of the work conductor wafer-8-200822216 30 is used. The electrostatic chuck 6 is constructed such that the electrode 6a is interposed between the insulators 6b, and a DC power source 12 is connected to the electrodes 6a. Then, by applying a DC voltage from the DC power source 12 to the electrode 6a, the semiconductor wafer 30 is adsorbed by Coulomb force or the like. A cold coal flow path (not shown) is formed inside the mounting table 2, and the semiconductor wafer 30 can be controlled to a specific temperature by circulating appropriate cold coal. Further, an exhaust ring 13 is provided on the outer side of the focus ring 5. The exhaust ring 13 is electrically connected to the processing chamber 1 through the support table 4. In the wall portion of the processing chamber 1, a plurality of gas ejection holes 18 are provided on the lower surface of the shower head 16 disposed to face the mounting table 2, and a gas introduction portion 16a is provided at the upper portion. Then, a space 17 is formed inside the inside. A gas supply pipe 15a is connected to the gas introduction portion 16a, and a process gas supply system 15 for supplying a processing gas (etching gas) for plasma uranium engraving is connected to the other end of the gas supply pipe 15a. The processing gas supplied from the processing gas system 15 is moved to the inside of the shower head 16 via the gas supply pipe 15a and the gas introduction portion 16a, and is discharged from the gas ejection hole 18 toward the semiconductor wafer 30. An example of the processing gas supplied from the processing gas supply system 15 is, for example, a mixed gas of n2/o2, a mixed gas of N2/H2, or the like. An exhaust port 1 is formed at a lower portion of the processing chamber 1, and an exhaust system 20 is connected to the exhaust port 19. Then, the inside of the processing chamber 1 can be depressurized to a specific degree of vacuum by operating the vacuum pump provided in the exhaust system 20. Further, a gate valve 24 for switching the inlet and outlet of the wafer 30 is provided on the side wall of the processing chamber 1. -9 - 200822216 Further, a ring magnet 21 is concentrically arranged around the processing chamber 1 so that a magnetic field is transmitted between the mounting table 2 and the shower head 16. The ring magnet 2 1 is rotatable by a rotating means such as a motor (not shown). The plasma etching apparatus having the above configuration is controlled by the control unit 60 in coordination. The control unit 60 includes a CPU, and is provided with a process controller 61 for controlling each part of the plasma etching apparatus, a use interface 62, and a memory unit 63. The user interface 62 is executed by an engineer to manage the plasma etching apparatus. The keyboard for input operation or a display for visualizing the operation state of the plasma uranium engraving device. The memory unit 63 stores a program program (software) for realizing various processes performed in the plasma etching apparatus by the control of the process controller 61, or a processing program for storing processing condition data and the like. Then, in response to the request, the memory unit 63 calls the instruction from the user interface 62 to cause the process controller 61 to execute, whereby the desired processing of the plasma device is performed under the control of the process controller 61. Furthermore, the processing program such as the control program or the processing condition data can be stored in a computer memory medium (such as a hard disk, a CD, a floppy disk, a semiconductor memory, etc.) that can be read by a computer, or It is utilized online from other devices, for example, via a dedicated loop. Next, a procedure for plasma etching the semiconductor wafer 30 in the plasma device having the above configuration will be described. First, the gate valve 24 is opened, and the semiconductor wafer 30 is carried into the processing chamber 1 via a load lock chamber (not shown) by a transfer arm or the like (not shown), and is placed on the mounting table 2, and then placed thereon. , to remove the handling robot arm to the outside of the processing chamber 1, and close the gate valve -10- 200822216 24 . Then, it is exhausted into the chamber 1 through the exhaust port 19 by a vacuum pump of the exhaust system 20. After the inside of the processing chamber 1 becomes a specific degree of vacuum, a specific processing gas (uranium engraved gas) is introduced into the processing chamber 1 to be introduced into the processing chamber 1'. The processing chamber 1 is maintained at a specific pressure, for example, 8.0 Pa. In this state, high frequency power having a frequency of, for example, 13·56 ΜΗζ and a power of, for example, 100 to 5 000 W is supplied from the RF power source 10 to the mounting table 2. At this time, a specific DC voltage is applied from the DC power source 12 to the electrode 6a of the electrostatic chuck 6, and the semiconductor wafer 30 is adsorbed by the Coulomb force. At this time, as described above, by applying high-frequency electric power to the mounting table 2 belonging to the lower electrode, an electric field is formed between the shower head 16 belonging to the upper electrode and the mounting table 2 belonging to the lower electrode. In addition, since the horizontal magnetic field is formed in the upper portion 1 a of the processing chamber 1 by the ring magnet 2 1 , the magnetron discharge is generated by the drift of electrons in the processing space of the semiconductor wafer 30, thereby forming The plasma of the processing gas, the uranium engraved semiconductor wafer 30 °, and then, when the specific etching process is completed, the supply of the high-frequency power and the supply of the processing gas are stopped, in the opposite procedure to the above procedure, from the processing chamber 1 The semiconductor wafer 30 is carried out. Next, the configuration of the focus ring 5 will be described with reference to Fig. 2 . Fig. 2 is a view schematically showing an important cross-sectional configuration of a portion on which the mounting table 2 of the focus ring 5 is placed. In the same figure, in order to easily understand the shape of each constituent member, a space is provided between the respective constituent members. The members are in contact with each other (except between the semiconductor wafer 30 and the focus ring 5). As shown in the figure, -11 - 200822216 focus ring 5 is composed of first ring member 5 a and second ring member 5 b disposed on the lower side of member 5a. The first annular member 5a is made of tantalum, carbon, SiC or the like and is formed in a ring shape. The first annular member 5a is formed with a segment portion 50 of the semiconductor wafer 30 placed on the mounting table 2, and the segment portion 50 is formed to extend below the semiconductive edge portion. Further, the outer portion of the segment portion 50 is the flat portion 51. The flat portion 51 is configured to be larger than the upper portion of the first annular member 5a before the start of use. The upper surface of the flat portion 51 is higher than the upper portion of the semiconductor crystal U placed on the mounting table 2. Further, the flat ginger of the first annular member 5a is exposed to the plasma and is gradually consumed, and the height is gradually lowered. The thickness of the first annular member 5a (about 4 mm in the second drawing, for example, 4 mm, the thickness (second) of the segment 50 is, for example, 2 · 5 mm, and the length in the radial direction of the segment 50 (e For example, the second annular member 5b is formed of, for example, an alumina ceramic edge material, and is formed in a ring shape. The second annular member is interposed between the first annular member 5a and the mounting table 2 In the lower side of the fitting member 5a, the second annular member 5b is directly placed on the mounting table 2 by the member 5a. The length of the first annular member 5a in the present embodiment is the radial direction (the second diameter and the same radial direction). Length (b in the second figure). The thickness of the member 5b (not shown in Fig. 2) The lower side of the inner edge portion of the first annular structure of the conductive material [body wafer 3 The upper surface of 0 is flat and high, at least in this case, the specific surface constituting the flat B 3 0 is further shaped by the exposure embodiment: d) is the c shown in the number of milligraphs. The first piece 5 b of the quartz or the like is placed in the first ring-shaped first ring state to form a), and the second ring is set to several millimeters left -12- 200 822216 is set to be 3 mm, for example, in the second figure, 40 is an outer casing made of quartz, and 41 is an insulator made of quartz or the like. In the present embodiment, the focus ring 5 is configured as described above. For the following reasons, a plasma uranium engraving device of the type that generates high-frequency electric power to the mounting table 2 (lower electrode) and generates plasma between the shower heads 16 (upper electrodes) that are set to the ground potential is used. By using the focus ring 5 constructed as described above, the plasma strength (density) formed in the upper space of the focus ring 5 can be reduced as compared with the prior art. Accordingly, the plasma can be concentrated on the portion to be placed thereon. The plasma strength (density) and the difference in strength (density) of the plasma formed in the space above the focus ring 5. As a result, the etching of the entire semiconductor wafer 30 can be improved. Rate, and can suppress the increase or decrease of the etching rate in the edge portion of the semiconductor wafer 30, and can improve the in-plane uniformity of the plasma etching process. Moreover, since it is formed in the upper space of the semiconductor wafer 30 Plasma, and The change in the plasma in the boundary portion of the plasma in the upper space of the focus ring 5 is smooth. Therefore, as shown in Fig. 2, either the first annular member 5a and the second annular member 5b constitute an extension. The lower side of the edge portion of the semiconductor wafer 30. In the first embodiment, the plasma etching of the organic photoresist mask is performed using the above-described condition of the focus ring 5. The gas is hungry: N2/〇2=200/22 sccm Pressure: 2.26Pa (1 7 mTorr)
高頻電力：3 00W 間隙：40mm 溫度：6 0 °C -13- 200822216 背面氦氣壓力（邊緣/中心）：93 1 /3 3 2 5 Pa(7/25T〇rr) 上述實施例1之結果，於使用石英製之第2環狀構件 5b之時，蝕刻率之平均値爲153.1nm/min，面內中之蝕率 刻之偏差程度爲±2.3%。再者，於使用氧化鋁（Al2〇3 ) 製之第2環狀構件5b時，蝕刻率之平均値爲147.4nm/ min，面內中之蝕刻率之偏差程度爲±1.8%。 比較例1是如第4圖所示般，使用不具有第2環狀構 件5b之一體型之以往聚焦環5 00，使其他蝕刻條件與上 述實施例1相同執行電漿蝕刻結果，蝕刻率之平均値爲 144.0nm/min，面內之蝕刻率之偏差程度爲±4.5%。並且 ，在該比較例1是在半導體晶圓3 0之邊緣部，於蝕刻率 變高之方向爲不均勻，該傾向在實施例1緩和。再者，於 使用氧化鋁陶瓷製之第2環狀構件5b時，比使用石英製 之第2環狀構件5 b時更加改善蝕刻率之面內均勻性。但 是，蝕刻率之平均値是使用石英製之第2環狀構件5b之 時比較高。如此一來，於第2環狀構件5b之材質不同時 ，由於介電率或介電損失等之特性不同，阻抗相對於高頻 之變化，故與作用效果產生不同。因此，以選擇適當絕緣 材料爲佳。 實施例2是使用上述構成之聚焦環5，利用以下之條 件執行有機系光阻罩幕之電漿蝕刻。 蝕刻氣體：N2/H2= 200/600sccm 壓力：7.98Pa ( 60mTorr) -14- 200822216High-frequency power: 3 00W Clearance: 40mm Temperature: 60 °C -13- 200822216 Backside helium pressure (edge/center): 93 1 /3 3 2 5 Pa(7/25T〇rr) Result of Example 1 above When the second annular member 5b made of quartz was used, the average enthalpy of the etching rate was 153.1 nm/min, and the degree of deviation of the etching rate in the in-plane was ±2.3%. Further, when the second annular member 5b made of alumina (Al2?3) was used, the average 値 of the etching rate was 147.4 nm/min, and the degree of variation in the etching rate in the plane was ±1.8%. In the first comparative example, as shown in Fig. 4, the conventional focusing ring 500 having one of the second annular members 5b is used, and other etching conditions are performed in the same manner as in the first embodiment, and the etching rate is performed. The average enthalpy was 144.0 nm/min, and the degree of deviation of the in-plane etching rate was ±4.5%. Further, in the comparative example 1, the edge portion of the semiconductor wafer 30 was uneven in the direction in which the etching rate was high, and this tendency was alleviated in the first embodiment. Further, when the second annular member 5b made of alumina ceramic is used, the in-plane uniformity of the etching rate is improved more than when the second annular member 5b made of quartz is used. However, the average 値 of the etching rate is relatively high when the second annular member 5b made of quartz is used. As a result, when the materials of the second annular member 5b are different, the characteristics of the dielectric constant or the dielectric loss are different, and the impedance changes with respect to the high frequency, which is different from the effect. Therefore, it is preferable to select an appropriate insulating material. In the second embodiment, the plasma etching of the organic photoresist mask was performed using the focus ring 5 of the above configuration. Etching gas: N2/H2=200/600sccm Pressure: 7.98Pa (60mTorr) -14- 200822216
高頻電力：700W 間隙：40mmHigh frequency power: 700W Clearance: 40mm
溫度：2 0 °C 背面氦壓力（邊緣/中央）：93 1 /3 3 25Pa(7/25Torr) 上述實施例2之結果，於使用石英製之第2環狀構件 5b之時，蝕刻率之平均値爲150.7nm/min，面內中之鈾率 刻之偏差程度爲±4.8%。再者，於使用氧化鋁（Al2〇3 ) 製之第2環狀構件5b時，鈾刻率之平均値爲145.7nm/ min，面內中之蝕刻率之偏差程度爲±3.2%。 比較例2是如第4圖所示般，使用不具有第2環狀構 件5 b之一體型之以往聚焦環5 0 0，使其他蝕刻條件與上 述實施例2相同執行電漿飩刻結果，鈾刻率之平均値爲 134.7nm/min，面內之蝕刻率之偏差程度爲±5.5%。並且 ，在該比較例2是在半導體晶圓3 0之邊緣部，於蝕刻率 下降之方向爲不均勻，該傾向在實施例2緩和。再者，於 使用鋁陶瓷製之第2環狀構件5b時，比使用石英製之第 2環狀構件5b之時更改善鈾刻率之面內均勻性。但是， 蝕刻率之平均値是比起使用石英製之第2環狀構件5b之 時變高。將上述實施例之結果表示於表1。 -15- 200822216 表1 鈾刻率（nm/min) 偏差程度（％ ) 施 例 1 石 英 153.1 2.3 氧 化 鋁 陶 瓷 147.4 1.8 比 較 例 1 144 4.5 實 施 例 2 石 英 150.7 4.8 氧 化 鋁 陶 瓷 145.7 3.2 比 較 例 2 134.7 5.5 上述實施例1、2之結果所示般，本實施形態是藉由 降低形成在聚焦環5之上部之空間之電漿強度（密度）， 可以使電漿集中於半導體晶圓3 0之上部之空間，藉由比 起以往提高形成在該部份之電漿之強度（密度）可以提高 鈾刻率。再者，藉由降低形成在聚焦環5上部之空間的電 漿之影響，可以改善半導體晶圓3 0之邊緣部中之蝕刻率 之不均勻性，提升蝕刻率之面內均勻性。此時，針對半導 體晶圓3 0之邊緣部中之蝕刻率有下降之傾向之時，和增 加之傾向之時的雙方找改善效果。 並且，如實施例2般於使用N2/H2當作蝕刻氣體之時 ，因產生沉積，故藉由使聚焦環5之上部之電漿強度下降 ，可以控制於提高半導體晶圓3 0之邊緣部之蝕刻率的方 向。另外，如實施例1般，於使用不產生沉積之氣體系時 ，藉由使聚焦環5之上部之電漿強度下降，可以控制於使 半導體晶圓3 0之邊緣部之蝕刻率下降之方向。 如上述般，在本實施形態中，因確認出由於聚焦環5 降低形成在該上部空間之電漿的強度（密度）之效果，故 -16- 200822216 在5點測量產生電漿後經過5分鐘之聚焦環5 (第2環狀 構件5b爲石英製表面之溫度而予以平均，溫度爲14〇它 。另外，以比較例所使用之聚焦環5 00執行相同之測量， 溫度爲1 7 6 °C。其結果，可以確認出由於聚焦環5降低形 成在該上部空間之電漿強度（密度）之效果。 再者，如第4圖（a) 、（b)所示般，聚焦環500由 於使用該表面被蝕刻而逐漸消耗，該高度逐漸變低（第4 圖（b ))。因此，形成在半導體晶圓30上之電漿之狀態 也藉由該聚焦環500之消耗而變動。在此以例而言，使用 聚焦環500，以KrF光阻作爲罩幕而執行蝕刻，形成線狀 之 S i Ο 2層，第4圖（a )所示之初期狀態中之線寬爲 1 3 0nm，對此2 1 0小時使用聚焦環5 0 0之後的第4圖（b )之狀態中之線寬爲131.9nm，產生大約2nm之CD ( c r i t i c a 1 d i m e n s i ο η )移動。如此之C D移動推測應是在初 期狀態形成在聚焦環500之上方之電漿，隨著聚焦環500 之消耗而逐漸移動製半導體晶圓3 0之上方，形成在半導 體晶圓3 0上之電漿變動。 另外，使用本實施形態之聚焦環5執行相同之電漿蝕 刻，在此第 3圖（a )所示之初期狀態中之線寬爲 13 0.2nm，對此210小時使用聚焦環5後之第3圖（b )之 狀態中之線寬爲129.8nm，可以將CD移動降低至0.4nm 。該理由推測是應於使用聚焦環5時，在初期狀態中形成 於聚焦環5之上方之電漿的強度低’故聚焦環5消耗而形 成於聚焦環5之上方的電漿強度即使變化，對半導體晶圓 -17- 200822216 3 0之上方的電漿的影響也較少之故。如此一來，本實施 形態之聚焦環5中，亦取得降低由於消耗所產生之C D移 動的效果。 並且，本發明並不限定於上述實施形態，亦可作各種 變形，例如，電漿蝕刻裝置並不限定於圖中所示之平行平 板型之下部1頻率施加型，亦可以適用於下部2頻率施加 型之電漿蝕刻裝置。 【圖式簡單說明】 第1圖爲模式性表示本發明之一實施形態所涉及之電 漿處理裝置之槪略構成的圖式。 第2圖爲模式性表示第1圖之重要部位剖面構成之圖 式。 第3圖爲用以說明聚焦環之消耗狀態之圖式。 第4圖爲用以說明以往之聚焦環之消耗狀態之圖式。 【主要元件符號說明】 1 :處理腔室 2 :載置台 5 :聚焦環 5 a :第1環狀構件 5 b :第2環狀構件 10 : RF電源 1 6 :噴淋頭 -18- 200822216 3 0 :半導體晶圓 -19-Temperature: 20 ° C Back pressure (edge/center): 93 1 / 3 3 25 Pa (7/25 Torr) As a result of the above Example 2, when the second annular member 5b made of quartz was used, the etching rate was The average enthalpy is 150.7 nm/min, and the degree of deviation of the uranium rate in the plane is ±4.8%. Further, when the second annular member 5b made of alumina (Al2?3) was used, the average enthalpy of the uranium engraving rate was 145.7 nm/min, and the degree of variation in the etching rate in the in-plane was ±3.2%. In the second comparative example, as shown in Fig. 4, the plasma etching process was performed in the same manner as in the above-described second embodiment, using the conventional focus ring 500 which does not have the shape of one of the second annular members 5b. The average enthalpy of the uranium engraving rate is 134.7 nm/min, and the degree of deviation of the etching rate in the plane is ±5.5%. Further, in Comparative Example 2, the edge portion of the semiconductor wafer 30 was uneven in the direction in which the etching rate was lowered, and this tendency was alleviated in the second embodiment. Further, when the second annular member 5b made of aluminum ceramic is used, the in-plane uniformity of the uranium engraving rate is improved more than when the second annular member 5b made of quartz is used. However, the average 値 of the etching rate becomes higher than that when the second annular member 5b made of quartz is used. The results of the above examples are shown in Table 1. -15- 200822216 Table 1 uranium engraving rate (nm/min) degree of deviation (%) Example 1 Quartz 153.1 2.3 Alumina ceramic 147.4 1.8 Comparative Example 1 144 4.5 Example 2 Quartz 150.7 4.8 Alumina ceramic 145.7 3.2 Comparative Example 2 134.7 5.5 As shown in the results of the first and second embodiments, in the present embodiment, by reducing the plasma strength (density) of the space formed in the upper portion of the focus ring 5, the plasma can be concentrated on the upper portion of the semiconductor wafer 30. The space can be increased by increasing the strength (density) of the plasma formed in the portion compared to the prior art. Further, by reducing the influence of the plasma formed in the space above the focus ring 5, the unevenness of the etching rate in the edge portion of the semiconductor wafer 30 can be improved, and the in-plane uniformity of the etching rate can be improved. At this time, the etching rate in the edge portion of the semiconductor wafer 30 tends to decrease, and both of them tend to improve when the tendency is increased. Further, when N2/H2 is used as the etching gas as in the second embodiment, deposition is caused, so that the edge of the semiconductor wafer 30 can be controlled by lowering the plasma strength of the upper portion of the focus ring 5. The direction of the etch rate. Further, as in the case of the first embodiment, when the gas system which does not cause deposition is used, the etching rate of the edge portion of the semiconductor wafer 30 can be controlled to be lowered by lowering the plasma strength of the upper portion of the focus ring 5. . As described above, in the present embodiment, since the effect of reducing the strength (density) of the plasma formed in the upper space by the focus ring 5 is confirmed, 16-200822216 is 5 minutes after the plasma is generated at 5 o'clock. The focus ring 5 (the second annular member 5b is averaged at a temperature of the surface of the quartz, and has a temperature of 14 。. In addition, the same measurement is performed with the focus ring 500 used in the comparative example, and the temperature is 1 7 6 °. C. As a result, it was confirmed that the focus ring 5 has an effect of lowering the plasma strength (density) formed in the upper space. Further, as shown in Fig. 4 (a) and (b), the focus ring 500 is The surface is gradually consumed by being etched, and the height is gradually lowered (Fig. 4(b)). Therefore, the state of the plasma formed on the semiconductor wafer 30 is also changed by the consumption of the focus ring 500. For example, the focus ring 500 is used, and etching is performed using the KrF photoresist as a mask to form a linear S i Ο 2 layer, and the line width in the initial state shown in FIG. 4( a ) is 1 3 . 0nm, the state of Figure 4(b) after the focus ring 5000 is used for this 21 hour The line width is 131.9 nm, which produces a CD (critica 1 dimensi ο η ) movement of about 2 nm. Such a CD movement is supposed to be a plasma formed above the focus ring 500 in an initial state, with the consumption of the focus ring 500. The plasma is oscillated above the semiconductor wafer 30 to form a plasma variation on the semiconductor wafer 30. Further, the same plasma etching is performed using the focus ring 5 of the present embodiment, and Fig. 3(a) The line width in the initial state shown is 13 0.2 nm, and the line width in the state of Fig. 3 (b) after the use of the focus ring 5 for 210 hours is 129.8 nm, which can reduce the CD shift to 0.4 nm. The reason is presumably that when the focus ring 5 is used, the strength of the plasma formed above the focus ring 5 in the initial state is low. Therefore, even if the plasma ring 5 is consumed, the intensity of the plasma formed above the focus ring 5 changes. The effect of the plasma above the semiconductor wafer -17-200822216 30 is also less. Thus, in the focus ring 5 of the present embodiment, the effect of reducing the CD movement due to consumption is also obtained. The invention is not limited to the above The embodiment may be modified in various ways. For example, the plasma etching apparatus is not limited to the parallel plate type lower portion 1 frequency application type shown in the drawing, and may be applied to the lower 2 frequency application type plasma etching apparatus. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a schematic configuration of a plasma processing apparatus according to an embodiment of the present invention. Fig. 2 is a view schematically showing a cross-sectional configuration of an important portion of Fig. 1 Fig. 3 is a diagram for explaining the state of consumption of the focus ring. Fig. 4 is a view for explaining the state of consumption of the conventional focus ring. [Description of main components] 1 : Processing chamber 2 : Mounting table 5 : Focus ring 5 a : First annular member 5 b : Second annular member 10 : RF power supply 1 6 : Shower head -18 - 200822216 3 0: Semiconductor Wafer-19-