201126597 六、發明說明： 【發明所屬之技術領域】 本發明係關於對LC D用基板等之被處理體，使用被 電漿化之氣體而予以蝕刻之電漿蝕刻方法。 【先前技術】 液晶顯示裝置（LCD: Liquid Crystal Display)等之 FPD ( Flat Panel Display )所使用之例如薄膜電晶體（ TFT: Thin Film Transistor)係藉由在玻璃基板等之被處 理基板上，一面圖案製作閘極電極或閘極絕緣膜、半導體 膜等，一面依序予以疊層而形成。 在被處理基板上形成TFT之後，將形成在最上層之 表面保護膜（鈍化膜）予以例如電漿蝕刻，形成配線連接 用之觸孔。在該觸孔具備有開口面積從上部朝向下部漸漸 縮小之錐面，依此使鈍化膜表面和上述錐面之交叉角成爲 鈍角，以防止埋入於孔內之配線斷線。 觸孔之錐面係事先將形成在鈍化膜上之光阻圖案予以 加熱處理形成錐面，而藉由蝕刻將該光阻圖案側之錐面形 狀轉印至鈍化膜側的所謂光阻後退法等所形成。 在此，於上述鈍化膜爲由例如矽和氮所構成之氮化矽 膜（以下，稱爲SiN膜）之時，將例如六氟化硫（SF6 ) 等之蝕刻氣體予以電漿化而執行電漿蝕刻。 通常，電漿蝕刻係在減壓環境下被執行’但是例如越 提高減壓環境之壓力，則可以越加大SiN膜之蝕刻速度。 201126597 另外，當減壓環境之壓力變高時’比起光阻之灰化速度’ SiN膜之蝕刻速度變大’產生了後述之下切的狀態’難以 控制觸孔之形狀，即是難以將光阻圖案之形狀精度佳地轉 印至鈍化膜。 如此一來，於蝕刻S iN膜之時的蝕刻速度和觸孔之形 狀控制之間具有折衷之關係。因此，於使例如錐面之形狀 控制優先之時，難以充分提高蝕刻速度，有難以提高蝕刻 處理之處理量的問題。 在此，在專利文獻1，記載有在1.33Pa(10mTorr) 〜13 3Pa ( lOOOmTorr)之範圍之壓力環境下將SF6予以電 漿化，蝕刻SiN膜之技術，在專利文獻2中，記載有在 IPa〜lOOPa之範圍之壓力環境下將氟氣及氧氣之混合氣 體予以電漿化，蝕刻S i N膜之技術。再者，在專利文獻3 ，記載有利用二氟化羰和氧之混合氣體而將SiN膜予以電 漿蝕刻之技術。 但是，即使在上述專利文獻1〜專利文獻3中所記載 之任一技術中，並無注目於S iN膜之蝕刻速度和錐面之形 狀控制之關係，無揭示用以邊良好保持例如錐面之形狀邊 提升蝕刻速度之條件。 [先行技術文獻] [專利文獻] [專利文獻1 ]日本特開平〇 1 - 1 4 6 3 2 8號公報：第3頁 右上欄第11行〜第16行 201126597 [專利文獻2]日本特開2008-3 00478號公報：段落號 碼 0014' 0027 [專利文獻3]日本特開2002- 1 5 8 1 8丨號公報：段落號 碼 0043 ' 0061 【發明內容】 [發明所欲解決之課題] 本發明係鑑於如此之情形而所硏究出，其目的係於提 供可控制良好形狀，並且可高速執行氮化矽膜之蝕刻的電 漿蝕刻方法。 [用以解決課題之手段] 本發明所涉及之電漿蝕刻方法係對形成在光阻圖案之 下層側的被處理基板上之氮化矽膜施予電漿蝕刻的方法， 上述光阻圖案具備開口面積從上部朝向下部漸漸縮小之開 口部，該電漿蝕刻方法其特徵爲：包含 將上述被處理基板搬入至處理容器內之工程：和 對該處理容器內供給六氟化硫和氧之混合氣體，在 133Pa以上、200Pa下之範圍內之壓力環境下將該混合氣 體予以電漿化而蝕刻上述氮化矽膜之工程。 上述混合氣體係六氟化硫和氧之體積比在1: 6以上 、：1 : 2 0以下之範圍內爲佳。 再者’其他發明所涉及之電槳蝕刻方法係對形成在光 阻圖案之下層側的被處理基板上之氮化矽膜施予電槳蝕刻 201126597 的方法，上述光阻圖案具備開口面積從上部朝向下部漸漸 縮小之開口部，該電漿蝕刻方法其特徵爲：包含 將上述被處理基板搬入至處理容器內之工程；和 對該處理容器內供給二氟化羰和氧之混合氣體，在 133Pa以上、267Pa下之範圍內之壓力環境下將該混合氣 體予以電漿化而蝕刻上述氮化矽膜之工程。 上述混合氣體係六氟化硫和氧之體積比在1 : 2以上 、3 : 20以下之範圍內爲佳。 再者，上述各電漿蝕刻方法適合於藉由蝕刻所形成之 上述氮化矽膜之開口部爲開口面積從上部朝下部漸漸縮小 之形狀之時。 [發明效果] 若藉由本發明，藉由使用將氧混合於六氟化硫或二氟 化羰之混合氣體而執行電漿蝕刻，即使在 133Pa ( lOOOmTorr)以上之高壓力環境下亦可取得安定之電漿， 並可以高速執行氮化矽膜之蝕刻。再者，藉由混合氣體含 有具有灰化光阻圖案之能力的氧，可調整氮化矽膜之蝕刻 速度和光阻圖案之灰化速度之比，可以將開口面積從上部 朝下部漸漸縮小之開口部之形狀從光阻圖案精度佳地轉印 至氮化矽膜上。 【實施方式】 第1圖爲表示放大適用本實施型態所涉及之電漿蝕刻 -8- 201126597 方法之被處理基板之一部分區域的縱斷側面圖。第I 示之被處理基板係例如主動矩陣方式之 LCD，圖中 爲設置在各畫素之TFT部之縱斷側面，1 b爲用以將 在TFT部1 a之例如閘極連接於LCD之驅動電路之接 之縱斷面圖。 TFT部1 a係在玻璃基板1 1上形成閘極配線膜 並且在其上方，設置由SiN膜等所構成之閘極絕緣g ，並且在其上層依序形成非晶質矽膜1 4或n +非晶質 1 5，以及訊號線膜，藉由蝕刻將訊號線及n+非晶質 15分離成左右，形成源極電極161、汲極電極162以 設置在該些電極1 6 1、1 6 2之間的通道部。 在如此所形成之TFT構造之上面側，設置有用 護TFT部1 a之表面的例如由SiN膜所構成之鈍化膜 在鈍化膜1 7，於源極電極1 6 1、汲極電極1 6 2之接觸 置有觸孔103，經該觸孔103而連接例如由ITO ( In Tin Oxide)等之透明電極所構成之電極膜18，例如 電極1 6 1係連接於源極電極1 6 1側之驅動電路，汲極 1 62係連接於各液晶畫素之驅動電極。 另外，接觸部1 b係成爲在連接於例如TFT部〗 閘極配線膜1 2的閘極配線膜1 2之上面側，從下方側 任一者皆由SiN膜所構成之先前所述之閘極絕緣膜1 鈍化膜1 7之順序而予以疊層之構造。然後，設置貫 些兩層之膜13、17之觸孔103，而在該觸孔103內 電極膜1 8，並將閘極配線膜1 2連接至閘極配線膜1 圖所 ，la 設置 觸部 12， 113 矽膜 矽膜 及被 以保 17° 部設 d i u m 源極 電極 a之 依照 3及 通該 形成 2側 -9- 201126597 之驅動電路。再者，在本實施型態中’被設置在TFT部 1 a及接觸部1 b之觸孔1 03係如在先前技術所說明般，爲 了達到防止電極膜1 8之斷線之目的’形成有開口面積從 上部朝下部漸漸縮小之錐面。 在具有以上所說明之構成之TFT部la、觸孔lb中， 被設置在各部1 a、1 b之觸孔1 03，從刪減光阻之消耗和 刪減製造工程等之觀點來看，一次執行蝕刻。例如，在第 2圖（a)、第2圖（b)所示之例中，以覆蓋TFT部la 及接觸部lb之全體之方式，塗佈光阻膜101而圖案製作 蝕刻用之開口部1 〇 2，形成光阻圖案。然後，經該些開口 部1 02，蝕刻鈍化膜1 7、閘極絕緣膜1 3，在各部1 a、1 b 形成有觸孔103。 如此一來，在TFT部1 a、接觸部1 b —次蝕刻觸孔 1 03之時，則在TFT部1 a側僅進行鈍化膜1 7之蝕刻，另 外在接觸部1 b側必須蝕刻鈍化膜1 7及閘極絕緣膜1 3， 蝕刻厚度不同之SiN膜。因此，也在TFT部1 a側形成觸 孔103而成爲可與各電極161、162接觸之後，在接觸部 1 b側，觸孔1 03還未到達至閘極配線膜1 2，有需要繼續 進行蝕刻之情形。因此，觸孔1 03 —次蝕刻所使用之蝕刻 氣體係必須爲不會蝕刻掉TFT部1 a側之訊號線膜（源極 電極1 6 1、汲極電極1 6 2 )之性質者。 再者，如先前所述般，在觸孔部1 b側之觸孔1 03設 置有用以防止電極膜1 8之斷線的錐面，該錐面係藉由光 阻後退法而形成。對所塗布之光阻膜1 0 1圖案製作開口部 -10- 201126597 102之後，藉由加熱處理，如第3圖（a )模式性放大表 示般，開口部1 02之內端面成爲錐形狀。 如此在光阻膜1 01形成錐面之狀態下’當蝕刻鈍化膜 1 7時，因自光阻膜1 0 1之薄區域側開始蝕刻鈍化膜1 7， 故如第3圖（b )所示般，可以將光阻膜1 〇 1之錐面形狀 轉印至鈍化膜1 7。在此，如先前技術所述般，在利用電 漿蝕刻蝕刻鈍化膜1 7之時，爲了達到增大其蝕刻速度之 目的，當提高執行電漿蝕刻之減壓環境之壓力時，比起光 阻膜1 〇 1側之灰化速度，鈍化膜1 7的蝕刻速度變大。該 結果，係如第3圖（C )所示般，在光阻膜1 〇 1之下面， 進行著鈍化膜1 7之蝕刻，產生了無法正確將光阻膜1 〇 1 之錐形狀轉印至鈍化膜1 7之下切的狀態。再者，該下切 即使在TFT部1 a側之觸孔1 03也有可能發生。 再者，適用本實施型態所涉及之電漿蝕刻方法之被處 理基板，係構成例如長邊爲2m以上之大型角型基板。如 此於對大型被處理基板執行電漿蝕刻之時，則需要在可收 納該被處理基板之大型處理容器內，將蝕刻氣體予以均勻 電漿化。尤其，從增加蝕刻速度之觀點來看，當提高處理 容器內之減壓環境之壓力時，形成了不均勻電漿，也有難 以在被處理基板面內進行均勻之蝕刻的問題。 如上述說明般，在第1圖所示之被處理基板形成觸孔 1 03之電漿蝕刻中，爲了提升蝕刻速度以提高處理量，必 須考慮（1 )於蝕刻在TFT部1 a、接觸部1 b之不同區域 厚度爲不同之SiN膜時，抑制SiN膜薄的TFT部1 a側之 -11 - 201126597 訊號線膜（源極電極i61、汲極電極162)中之蝕刻進行 ，（2)抑制下切之產生，（3)在被處理基板之整個表面 形成均勻之電漿等，而執行蝕刻氣體之選定或處理條件之 設定。本實施型態所涉及之電漿蝕刻方法係滿足該些要求 ，並且可以較以往高速執行S iN膜之蝕刻。以下，針對其 詳細內容予以說明。 以下，第4圖表示實施本實施型態所涉及之電漿蝕刻 方法之電漿裝置之構成例。第4圖之縱斷側面圖所示之電 漿蝕刻裝置2係如第3圖（a )所示般，開口部102之被 圖案製作之光阻膜1 〇 1係對最上面被塗佈之被處理基板S ，發揮藉由電漿蝕刻在TFT部1 a及接觸部1 b形成觸孔 1 〇 3之作用。 電漿蝕刻裝置2係在其內部具備有用以蝕刻被處理基 板S之真空腔室之處理容器20。本實施型態所涉及之電 漿蝕刻裝置2係如先前所述般，可處理例如長邊爲2m以 上之大型角型基板，即使針對處理容器20，也成爲例如 水平剖面之一邊爲3.5m，另一邊爲3.0m左右之大小的角 型。 處理容器20係藉由鋁等之熱傳導性及導電性良好之 材質所構成，並且該處理容器20被接地。再者，在處理 容器20之一個側壁部21，形成用以將被處理基板S搬入 至處理容器20內之搬入搬出口 22，該搬入搬出口 22係 構成藉由閘閥23形成開關自如。[Technical Field] The present invention relates to a plasma etching method for etching a substrate to be processed such as a substrate for LCD using a plasma gas. [Prior Art] For example, a thin film transistor (TFT: Thin Film Transistor) used in an FPD (Flat Panel Display) such as a liquid crystal display (LCD) is used on a substrate to be processed such as a glass substrate. A gate electrode, a gate insulating film, a semiconductor film, or the like is patterned to be laminated in order. After the TFT is formed on the substrate to be processed, the surface protective film (passivation film) formed on the uppermost layer is subjected to, for example, plasma etching to form a contact hole for wiring connection. The contact hole has a tapered surface whose opening area gradually decreases from the upper portion toward the lower portion, whereby the intersection angle between the surface of the passivation film and the tapered surface becomes an obtuse angle to prevent the wiring buried in the hole from being broken. The tapered surface of the contact hole is formed by previously heat-treating the photoresist pattern formed on the passivation film to form a tapered surface, and transferring the tapered surface shape of the photoresist pattern side to the side of the passivation film by etching. Waiting for it to form. Here, when the passivation film is a tantalum nitride film (hereinafter referred to as a SiN film) made of, for example, hafnium and nitrogen, an etching gas such as sulfur hexafluoride (SF6) is plasma-formed and executed. Plasma etching. Generally, the plasma etching is performed under a reduced pressure environment. However, for example, the pressure of the reduced pressure environment is increased, the etching rate of the SiN film can be increased. In addition, when the pressure in the decompression environment becomes high, 'the ashing speed of the SiN film becomes larger than the ashing speed of the photoresist', and the state of the undercut is described later. It is difficult to control the shape of the contact hole, that is, it is difficult to light. The shape of the resist pattern is transferred to the passivation film with high precision. As a result, there is a trade-off relationship between the etching speed at the time of etching the SiN film and the shape control of the contact holes. Therefore, when the shape control of the tapered surface is prioritized, it is difficult to sufficiently increase the etching rate, and it is difficult to increase the processing amount of the etching treatment. Here, Patent Document 1 discloses a technique of sizing SF6 in a pressure environment in the range of 1.33 Pa (10 mTorr) to 13 3 Pa (100 Torr), and etching the SiN film. Patent Document 2 describes that A technique in which a mixed gas of fluorine gas and oxygen is plasma-treated and a SiN film is etched under a pressure environment in the range of IPa to 100 Pa. Further, Patent Document 3 describes a technique in which a SiN film is plasma-etched by using a mixed gas of carbonyl difluoride and oxygen. However, in any of the techniques described in Patent Documents 1 to 3, the relationship between the etching rate of the SiN film and the shape control of the tapered surface is not noticed, and it is not disclosed that the tapered surface is well maintained. The shape increases the condition of the etching rate. [Patent Document 1] [Patent Document 1] Japanese Patent Laid-Open Publication No. 1 - 1 4 6 3 2 8: Page 3, right upper column, 11th line to 16th line, 201126597 [Patent Document 2] Japanese Patent Publication No. 2008-00478: Paragraph No. 0014' 0027 [Patent Document 3] JP-A-2002- 1 5 8 1 8 公报 : 段落 段落 段落 段落 段落 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 004 In view of such circumstances, the object is to provide a plasma etching method which can control a good shape and can perform etching of a tantalum nitride film at high speed. [Means for Solving the Problem] The plasma etching method according to the present invention is a method of applying plasma etching to a tantalum nitride film formed on a substrate to be processed on a layer side of a photoresist pattern, wherein the photoresist pattern is provided An opening portion whose opening area gradually decreases from an upper portion toward a lower portion, the plasma etching method comprising: a process of loading the substrate to be processed into a processing container: and supplying a mixture of sulfur hexafluoride and oxygen to the processing container. The gas is subjected to slurrying of the mixed gas in a pressure environment in a range of 133 Pa or more and 200 Pa to etch the above-described tantalum nitride film. The volume ratio of sulfur hexafluoride and oxygen in the above mixed gas system is preferably in the range of 1:6 or more and 1:20 or less. Further, the electric paddle etching method according to another invention is a method of applying an electric paddle etching 201126597 to a tantalum nitride film formed on a substrate to be processed under the photoresist pattern, wherein the photoresist pattern has an opening area from the upper portion. The plasma etching method is characterized in that it includes a process of carrying the substrate to be processed into a processing container, and a mixed gas of dicarbonyl fluoride and oxygen is supplied to the processing container at 133 Pa. The above-described process of etching the above-described tantalum nitride film by plasma-mixing the mixed gas under a pressure environment within a range of 267 Pa. The volume ratio of sulfur hexafluoride and oxygen in the above mixed gas system is preferably in the range of 1:2 or more and 3:20 or less. Further, each of the plasma etching methods is suitable for a case where the opening of the tantalum nitride film formed by etching has a shape in which the opening area gradually decreases from the upper portion to the lower portion. [Effect of the Invention] According to the present invention, by performing plasma etching by mixing oxygen with a mixed gas of sulfur hexafluoride or difluorocarbonyl, stability can be achieved even under a high pressure environment of 133 Pa (100 Torr) or more. The plasma is etched and the tantalum nitride film can be etched at high speed. Furthermore, by adjusting the gas containing the oxygen having the ability to ash the photoresist pattern, the ratio of the etching rate of the tantalum nitride film to the ashing speed of the photoresist pattern can be adjusted, and the opening area can be gradually reduced from the upper portion to the lower portion. The shape of the portion is transferred from the photoresist pattern to the tantalum nitride film with high precision. [Embodiment] Fig. 1 is a longitudinal sectional side view showing a partial region of a substrate to be processed to which the plasma etching method of the present embodiment is applied to the plasma etching -8-201126597. The substrate to be processed shown in Fig. 1 is, for example, an active matrix type LCD, which is provided on the longitudinal side of the TFT portion of each pixel, and 1b is for connecting, for example, a gate electrode of the TFT portion 1a to the LCD. A longitudinal section of the drive circuit. The TFT portion 1a forms a gate wiring film on the glass substrate 11 and is provided with a gate insulating g composed of a SiN film or the like thereon, and sequentially forms an amorphous germanium film 14 or n in the upper layer thereof. + amorphous 1 5, and a signal line film, the signal line and the n + amorphous 15 are separated into left and right by etching, and a source electrode 161 and a drain electrode 162 are formed to be disposed on the electrodes 1 6 1 and 16 The channel between the two. On the upper surface side of the TFT structure thus formed, a passivation film made of, for example, a SiN film for protecting the surface of the TFT portion 1a is provided on the passivation film 17 on the source electrode 161 and the drain electrode 16 2 The contact hole 103 is placed in contact with the contact hole 103, and the electrode film 18 made of, for example, a transparent electrode such as ITO (In Tin Oxide) is connected, for example, the electrode 161 is connected to the source electrode 161 side. In the driving circuit, the drain 1 62 is connected to the driving electrodes of the respective liquid crystal pixels. In addition, the contact portion 1b is formed on the upper surface side of the gate wiring film 12 which is connected to, for example, the TFT portion gate wiring film 12, and the previously described gate is formed of any SiN film from the lower side. The structure in which the gate insulating film 1 is laminated in the order of the passivation film 1 is laminated. Then, the contact holes 103 of the two layers of the film 13, 17 are disposed, and the electrode film 18 is disposed in the contact hole 103, and the gate wiring film 12 is connected to the gate wiring film 1 The 12, 113 decidual film and the driving circuit for forming the dium source electrode a in accordance with 3 and the 2 side -9-201126597. Further, in the present embodiment, the contact hole 103 which is provided in the TFT portion 1a and the contact portion 1b is formed to prevent the disconnection of the electrode film 18 as described in the prior art. There is a tapered surface whose opening area gradually decreases from the upper portion to the lower portion. In the TFT portion 1a and the contact hole 1b having the above-described configuration, the contact hole 103 of each of the portions 1a and 1b is provided, from the viewpoint of the reduction of the photoresist consumption and the manufacturing process, etc. Etching is performed once. For example, in the example shown in FIG. 2(a) and FIG. 2(b), the photoresist film 101 is applied so as to cover the entire TFT portion 1a and the contact portion 1b, and the opening for etching is patterned. 1 〇 2, forming a photoresist pattern. Then, the passivation film 17 and the gate insulating film 13 are etched through the opening portions 102, and the contact holes 103 are formed in the respective portions 1a and 1b. As a result, when the TFT portion 1a and the contact portion 1b are etched by the contact portion 1b, only the passivation film 17 is etched on the TFT portion 1a side, and the passivation portion 1b side must be etched and passivated. The film 17 and the gate insulating film 13 are etched with SiN films having different thicknesses. Therefore, after the contact hole 103 is formed on the side of the TFT portion 1a so as to be in contact with each of the electrodes 161 and 162, on the side of the contact portion 1b, the contact hole 103 has not yet reached the gate wiring film 12, and it is necessary to continue. The case of etching. Therefore, the etching gas system used for the first etching of the contact hole 103 must be such that the signal line film (source electrode 161 and drain electrode 162) of the TFT portion 1a side is not etched away. Further, as described above, the contact hole 103 on the side of the contact hole portion 1 b is provided with a tapered surface for preventing the disconnection of the electrode film 18, which is formed by the photoresist back-off method. After the opening portion -10- 201126597 102 is formed on the applied photoresist film 10 1 pattern, the inner end surface of the opening portion 102 has a tapered shape as shown by the patterning of Fig. 3 (a) by heat treatment. Thus, when the passivation film 117 is formed in a tapered state, when the passivation film 17 is etched, the passivation film 17 is etched from the thin region side of the photoresist film 010, so as shown in Fig. 3(b) As shown, the tapered surface shape of the photoresist film 1 〇 1 can be transferred to the passivation film 17 . Here, as described in the prior art, when the passivation film 17 is etched by plasma etching, in order to increase the etching speed thereof, when the pressure of the decompression environment in which the plasma etching is performed is increased, the light is compared. The ashing speed of the resist film 1 〇1 side, the etching rate of the passivation film 17 becomes large. As a result, as shown in FIG. 3(C), under the photoresist film 1 〇1, the passivation film 17 is etched, and the tapered shape of the photoresist film 1 〇1 cannot be accurately transferred. To the state under which the passivation film 17 is cut. Further, this undercutting may occur even in the contact hole 103 of the TFT portion 1a side. Further, the substrate to be processed to which the plasma etching method according to the present embodiment is applied is, for example, a large-angle substrate having a long side of 2 m or more. When plasma etching is performed on a large substrate to be processed, it is necessary to uniformly plasma the etching gas in a large processing container that can receive the substrate to be processed. In particular, from the viewpoint of increasing the etching rate, when the pressure of the reduced pressure environment in the processing container is increased, uneven plasma is formed, and there is a problem that it is difficult to perform uniform etching in the surface of the substrate to be processed. As described above, in the plasma etching of the contact substrate forming the contact hole 103 shown in Fig. 1, in order to increase the etching rate to increase the amount of processing, it is necessary to consider (1) etching in the TFT portion 1a, the contact portion. When the thickness of the different regions of 1 b is different, the etching in the -11 - 201126597 signal line film (source electrode i61, drain electrode 162) of the TFT portion 1 a side of the thin portion of the SiN film is suppressed, (2) The generation of the undercut is suppressed, and (3) a uniform plasma or the like is formed on the entire surface of the substrate to be processed, and the selection of the etching gas or the setting of the processing conditions is performed. The plasma etching method according to this embodiment satisfies these requirements, and the etching of the SiN film can be performed at a higher speed than in the past. The details will be described below. Hereinafter, Fig. 4 shows an example of the configuration of a plasma device for carrying out the plasma etching method according to the present embodiment. In the plasma etching apparatus 2 shown in the longitudinal side view of Fig. 4, as shown in Fig. 3(a), the patterned photoresist film 1 开口1 of the opening portion 102 is coated on the uppermost side. The substrate S to be processed functions to form the contact holes 1 〇 3 in the TFT portion 1 a and the contact portion 1 b by plasma etching. The plasma etching apparatus 2 is provided with a processing container 20 having a vacuum chamber for etching the substrate S to be processed therein. The plasma etching apparatus 2 according to the present embodiment can process, for example, a large-angle substrate having a long side of 2 m or more as described above, and even for the processing container 20, for example, one side of the horizontal section is 3.5 m. The other side is an angle of about 3.0 m. The processing container 20 is made of a material having good thermal conductivity and electrical conductivity such as aluminum, and the processing container 20 is grounded. Further, in one side wall portion 21 of the processing container 20, a loading/unloading port 22 for carrying the substrate S to be processed into the processing container 20 is formed, and the loading/unloading port 22 is configured to be opened and closed by the gate valve 23.
在處理容器2 0之內部，配置有用以將被處理基板S -12 - 201126597 載置在其上面之載置台3。載置台3係配置電性 理容器20之底面上，發揮當作下部電極之作用 極電極發揮功能。 再者，在載置台3之周緣區域及側面，藉由 漿均勻形成在載置台3上方之例如由陶瓷材料所 焦環33而被覆蓋。聚焦環33係發揮調整被處理 周緣之區域之電漿狀態的作用，例如使電漿集中 基板S上，提升蝕刻速度之作用。在本實施型態 被處理基板S之載置區域係被形成橫跨例如包含 之上面，和其周圍之聚焦環33之上面之一部分白 在載置台3設置有用以在被設置在外部的無 運裝置和該載置台3之間執行被處理基板S之交 銷34。升降銷34係與升降機構35連接，從載 表面伸縮自如，可以在執行被處理基板S之收授 先前所述之載置區域之間，使被處理基板S升降 36係爲了將處理容器20內保持真空，覆蓋升降 伸縮體。 在一方載置台3之上方，以與該載置台3之 之方式，設置平板狀之上部電極4，該上部電極 於角板狀之上部電極基座4 1。該些上部電極4 極基座41係藉由例如鋁所構成，互相導通。上 座4 1之上面係經絕緣構件4 1 1而被安裝於處理$ 頂棚，成爲自處理容器2 0電性浮起之狀態。在 基座41連接有電漿產生用之高頻電源部48，其 連接於處 ，當作陽 用以使電 構成之聚 基板S之 於被處理 中，載置 「載置台3 勺區域。 圖示之搬 接的升降 置台3之 之位置和 。圖中， r銷3 4之 上面對向 4被支撐 及上部電 部電極基 穿器20之 上部電極 結果上部 -13- 201126597 電極4當作陰極電極而發揮功能。再者，該些藉由上部電 極基座4 1及上部電極4所包圍之空間構成蝕刻氣體之氣 體擴散空間42。以下，將該些上部電極4、上部電極基座 41總稱爲氣體噴淋頭40。 在處理容器20之頂棚部以連接於上述擴散空間42之 方式設置有氣體供給路43，該氣體供給路43分歧爲兩根 ，在一方側之蝕刻氣體供給路43 1連接蝕刻氣體供給部 45，在另一方側之氧供給路43 2連接有氧供給部46。在 蝕刻氣體供給部45，貯藏有用以蝕刻被處理基板S之SiN 膜之六氟化硫（以下，表記爲SF6 )，可以在氣體之狀態 下將SF6朝向處理容器20予以供給。另外，在氧供給部 46貯藏有用以使在處理容器20內產生之電漿安定化，並 且調節光阻膜1 0 1之灰化速度而抑制下切之產生的氧（以 下，表記爲〇2 )，發揮將與SF6混合之狀態之02供給至 處理容器20之作用。 在蝕刻氣體供給部45、氧供給部46和擴散空間42 之間之各供給路43 1、432間設置有例如由質量流量控制 器所構成之流量調節部44。流量調節部44係具備根據來 自後述控制部6之指示，調節對處理容器2 0之S F 6及Ο 2 之供給量，依此發揮調節S F 6和Ο 2之混合比之作用。 本實施型態所涉及之電漿蝕刻方法中，流量調節部 44可以在將SF6和02混合成例如1 : 6以上、1 : 20以下 之範圍之體積比的狀態下供給至處理容器2 0。當舉出具 體例時，在本例中流量調節部44係例如被控制成將SF6 -14- 201126597 之流量調節至 l〇〇sccm(sccm:ml/min(0°C，1 氣壓） 以下相同）’將〇 2調節至6 0 0 s c c m，將混合成1 : 6之體 積比之混合氣體供給至處理容器2 0。 如此一來，當被混合之氣體供給至擴散空間4 2時， 該混合氣體經設置在上部電極4之氣體供給孔4 7而被供 給至被處理基板S上方之處理空間，被電漿化而可以對被 處理基板S進行蝕刻處理》 另外，在處理容器20之底面連接有排氣處理容器20 內之環境之排氣路2 4之一端側，在其另一端側，經壓力 調節閥511而連接有真空泵51，處理容器20內之氣體係 自該排氣路2 4朝向例如工場共通之除害裝置5 2而排氣。 在此，在以往之電漿蝕刻方法中，係在處理容器2 0 內之壓力被減壓至例如低於1 3 3 P a ( 1 0 0 0 m T o r r )例如 13.3Pa(l〇〇mTorr)左右之高真空環境之處理容器20內 ’供給例如不混合Ο 2之S F 6而執行s i N膜之蝕刻。在該 程度之高真空環境中，即使如本例般之大型處理容器20 ’電漿也安定’也有可以抑制下切產生之情形。但是，有 在高真空環境中’ S iN膜之蝕刻速度慢，無法取得充分之 處理量之問題。 另外，當一面單獨供給SF6，一面提高處理容器20 內之壓力時’則難以形成安定之電漿，並且顯著產生下切 之可能性變高。在此，以往之電漿蝕刻裝置並非設計成在 例如1 33Pa ( 1 〇〇〇mT〇rr )以上之比較低真空之壓力環境 下實行蝕刻’即使針對真空泵，亦採用可形成高真空環境 -15- 201126597 比較高價之渦輪分子泵等之真空泵。 對此，在本實施型態所涉及之電漿蝕刻方法中，如先 前所述般，以例如體積比1 : 6〜1 : 2 0之範圍於S F 6混合 〇 2，依此即使在壓力比較高之環境下，亦安定形成電漿， 並且可以調節SiN膜之蝕刻速度和光阻膜1 〇 1之灰化速度 之比而設成難以產生下切之狀態。 因在處理容器20內形成如此之壓力環境，故本實施 型態所涉及之真空泵5 1及壓力調節閥5 1 1係根據無圖示 之壓力計之指示，調節壓力調節閥5 1 1之開口度，依此可 以將處理容器20內之壓力調節成例如i33Pa( 1000mTorr )以上’ 200Pa( 1500mTorr)以下之範圍內之例如l33Pa (lOOOmTorr )。如此一來，比起以往之高真空環境，由 於在低真空之狀態可執行電漿鈾刻，故真空泵5 1無法如 例如渦輪分子泵般製作出高真空狀態，但是藉由比較便宜 之乾式泵構成。 再者’電漿蝕刻裝置2係與控制部6連接。控制部6 係由具備有例如無圖示之CP U和程式之電腦所構成，在 程式編寫有該電黎触刻裝置2之動作，即是將被處理基板 S搬入至處理容器20內，並調節對處理容器20供給SF6 及〇2之供給量，供給比以及處理容器2 0內之壓力後，將 蝕刻氣體（SF6和02之混合氣體）予以電漿化，組成針 對從對被處理基板S施予蝕刻處理後至搬出爲止之動作所 涉及之控制等之步驟（命令）群。該程式係被儲存於例如 硬碟、CD、光磁性碟、記憶卡等之記憶媒體，自此被安 -16- 201126597 裝於電腦。 以下，針對本實施型態所涉及之蝕刻處理裝置2之動 作予以說明。首先，當經無圖示之操作部，使用者選擇目 的之電漿蝕刻處理之製程配方而輸入至控制部6時，在控 制部6中，根據該製程配方，對蝕刻處理裝置2之各部輸 出控制訊號，如此一來對基板S執行特定之電漿蝕刻處理 〇 首先，打開閘閥23，藉由無圖示之外部搬運手段， 如第2圖（a )所示般，將在表面形成有光阻膜1 〇〗之被 處理基板S搬入至處理容器20內，該光阻膜1〇1具備有 對應於觸孔1 03之開口部1 02，搬運至載置台3上方之收 授位置。 當被處理基板S到達至收授位置時，使升降銷3 4上 升而將被處理基板S從搬運手段收授至升降銷34，搬運 手段退出至處理容器20外，使升降銷3 4下降而將被處理 基板S載置在載置區域。之後當關閉搬入搬出口 2 2時， 使真空泵51運轉而藉由壓力調節閥511，將處理容器20 內調整成例如133Pa(l〇〇〇mTorr)之壓力，並且利用流 里調卽部44’進丫了流量調整，使SF6之流量成爲lOOsccm ’ 〇2之流量成爲60〇Sccm (體積比1:6)，而將兩氣體 從蝕刻氣體供給部45及氧供給部46供給至處理容器20 〇 SF6及〇2係在氣體供給路43及擴散空間42內充分 被混合’經氣體供給孔4 7而被吐出至處理容器2 〇內。然 -17- 201126597 後，從高頻電源部48將高頻電力供給至上部電極 被處理基板S之上方側之空間形成電漿，並對SiN 電漿蝕刻。 在此，SF6爲絕緣性之氣體，雖持有難以在儲 被處理基板S之處理容器20內形成均勻之電漿， 由將持有促進SF6之解離之效果的〇2，以sf6和 積比爲1 : 6〜1 : 2 0之高比率予以混合，則可以在 器20之全表面上形成均勻之電漿。該是以目視確 容器20內之電漿狀態，及即使在後述實施例中之 確認出。 另外，因〇2不具有蝕刻SiN膜之能力，故當 之混合比時，S iN膜之蝕刻速度也有變慢之可能性 ，在本例中，藉由將處理容器 20內之壓力設 1 3 3 Pa ( 1 OOmTorr )〜200Pa ( 1500mTorr) t 匕較高 環境，即使在提高〇2之混合比時，也有處理容器 S F 6之分子數較以往之時少，或也有增加之時。然 與0 2混合之混合氣體中，如先前所述般，因形成 電漿，故生成多數S F 6之活性種，有助於提升蝕刻 如此一來，即使針對提升SiN膜之蝕刻速度之點， 述之實施例中之實驗確認出。 再者，被混合於SF6之02雖然無蝕刻SiN膜 ，但是因持有灰化光阻膜1 〇 1之能力，故可以補 SiN膜之蝕刻速度之部分，也提高光阻膜】〇丨之灰 。其結果，SiN膜和光阻膜1 01例如均等被削取， 4而在 膜實行 存大型 但是藉 〇2之體 :處理容 認處理 .實驗也 提局〇 2 。但是 爲例如 之壓力 20內之 後，在 安定之 速度。 也在後 之能力 足提升 化速度 無產生 -18- 201126597 下切而形成SiN膜’可以良好執行觸孔1 〇3之形狀控制。 即使針對該點，也在後述之實施例中之實驗確認出。 並且，構成源極電極1 6 1或汲極電極1 6 2之訊號線膜 如疊層Mo和A1之Mo/Al/Mo疊層膜般包含Mo之時， SF6爲了蝕刻Mo，與SiN膜之選擇比（SiN膜對Mo之蝕 刻速度的比例）成爲重要。但是，藉由提高〇 2之混合比 ，可以增大該選擇比。 電漿化之氣體係降下在處理容器20內而到達被處理 基板S，在其表面進行蝕刻處理。然後，該氣體一面傳達 被處理基板S之表面，一面流至周緣部側，通過聚焦環 33和處理容器20之間之空間而流入排氣路24，排氣至處 理容器2 0之外。如此一來，根據製程配方，當進行特定 時間電漿蝕刻處理時，停止SF6、02或高頻電力之供給， 將處理容器2 0內之壓力返回至原來之狀態之後，以與搬 入時之相反順序，將被處理基板S從載置台3收授至外部 之搬運手段而從電漿蝕刻裝置2搬出，完成一連串蝕刻處 理。 若藉由本實施型態所涉及之電漿蝕刻處理方法時，則 有以下之效果。藉由使用混合SF6和02之混合氣體而執 行電漿蝕刻，即使在 1 3 3 P a ( 1 0 0 0 m T o r r )以上之高壓力 環境下亦可取得安定之電漿，並可以高速蝕刻SiN膜。再 者，藉由混合氣體含有具有灰化光阻膜101之能力的02 ，可調整SiN膜之蝕刻速度和光阻膜1 〇丨之灰化速度之比 ，可以將開口面積從上部朝下部漸漸縮小之開口部1 02之 -19 - 201126597 形狀從光阻膜1 0 1轉印至s i N膜上，對於形成觸孔1 0 3， 可以進行良好之形狀控制。 再者，因可以在較以往低之真空環境下，執行SiN膜 之蝕刻’故藉由採用比較低價之乾式泵等代替形成高真空 環境之渦輪分子泵以當作真空泵5 1，可以降低電漿蝕刻 裝置2之裝置成本。 接著，針對本發明之第2實施型態所涉及之電漿處理 方法予以說明。第2實施型態所涉及之電漿處理方法係可 以藉由具備幾乎與第4圖所示相同之構成的電漿蝕刻裝置 2進行實施，以下爲不同點。 在第2實施型態所涉及之電漿蝕刻裝置2中，採用溫 暖化係數幾乎與二氧化碳相等之二氟化羰（COF2 )以當 作蝕刻SiN膜之蝕刻氣體，在蝕刻氣體供給部45貯藏 COF2以取代SF6。再者，本例之流量調節部44係以將 COF6和02混合成例如1 : 2以上、3 : 20以下之範圍之體 積比予以混合的混合氣體供給至處理容器20。 第2實施型態所涉及之真空泵5 1及壓力調節閥5 1 1 ，係具備根據無圖示之壓力計之指示，調節壓力調節閥 511之開口度，依此可將處理容器20內之壓力環境調節 成例如 133Pa ( 1 OOOmTorr )以上、2 6 7 P a ( 2 0 0 0 m T o r r ) 以下之範圍內之能力。 在以上說明之條件下，即使在將COF2和02之混合氣 體予以電漿化而執行處理基板S之電漿蝕刻之時，可以取 得安定電漿之形成、提升SiN膜之蝕刻速度、抑制下切產 -20- 201126597 生之觸孔1 03的形狀控制、防止一次飩刻TFT部1 a和接 觸部1 b時之訊號線膜（源極電極1 6 1、汲極電極1 6 2 )崩 落、由於採用低真空泵而降低設備成本等之各種效果。 在此，從處理容器2 0排出之混合氣體，係在除害裝 置52捕獲同氣體中所含之COF2的大部分，殘留的〇2被 放出至大氣。但是，除害裝置52中之COF2之捕獲效率 因並非100%，故也有僅有些微量之 COF2被放出至大氣 。即使在如此之情形，如先前所述般，因COF2是溫暖化 係數與二氧化碳同等之物質，故可以降低對環境所造成之 負擔。 以上所說明之第1、第2實施型態所涉及之電漿蝕刻 方法，並不限定於第1圖所示之一次蝕刻被處理基板S上 之T F T部1 a、接觸部1 b之時，亦可以適用於個別蝕刻兩 個區域之時。 再者，將處理容器 20之壓力調節至 133Pa( 1 OOOmTorr )以上而使電漿產生之上述電漿處理方法，亦 可以適用於對處理容器2 0內僅供給〇2而灰化光阻膜1 0 1 ，自被處理基板S予以除去之電漿灰化方法。以往，在較 執行電漿灰化之例如133Pa ( lOOOmTorr )高之壓力環境 下執行灰化，依此對形成在被處理基板S上之裝置所造成 之傷害低，可以執行高速之灰化處理。 [實施例] (實驗1 ) -21 - 201126597 使用與第4圖所記載之電漿蝕刻裝置2同等構成之蝕 刻處理裝置，使SFs和〇2之混合氣體予以電漿化，形成 在表面圖案製作光阻膜1 〇 1之SiN基板之蝕刻，測量SiN 之蝕刻速度（E/R )、光阻膜1 〇〗之灰化速度（a/R )、 選擇比（光阻膜101對SiN之蝕刻速度之灰化速度比）。 自高頻電源部48供給13.56MHz、3000W之高頻電力30 秒間。再者’載置台3之溫度調節成251。 A .實驗條件 (實施例1-1)以lOOsccm供給SF6，以600sccm供 給〇2(體積比1: 6)，處理容器20內之壓力設爲133Pa (lOOOmTorr)。 (實施例1-2 )除將處理容器20內之壓力設爲160Pa (1 200mT〇rr )之點外，其他設成與（實施例1-1 )相同 之條件。 (比較例1-1A)除將處理容器 20內之壓力設爲 2 6 · 7 P a ( 2 0 0m T 〇 r r )之點外，其他設成與（實施例1 -1 ) 相同之條件。 (比較例1-2A )除將處理容器20內之壓力設爲 53.3Pa ( 400mTorr )之點外，其他設成與（實施例1-1 ) 相同之條件。 (比較例1-3A)除將處理容器 20內之壓力設爲 107Pa( 800mTorr)之點外，其他設成與（實施例1-1) 相同之條件。 -22- 201126597 B .實驗結果 在第5圖表示（實施例1 - 1〜1 - 2 )、（比較例1 - 1 A 〜1-3A)之結果。第5圖之橫軸表示處理容器20內之壓 力，上段之數値係以[m T 〇 r r ]單位表示，下段之數値係以 [P a]單位表示。右側之縱軸係表示S i N之蝕刻速度或光阻 膜1 0 1之灰化速度[n m / m i η ] ’左側之縱軸係表示選擇比[_ ] ，即是光阻膜101對SiN之蝕刻速度之灰化速度之比。 第5圖所示之空白菱形之記號係表示各實施例、比較 例中之S i N之蝕刻速度，實線表示其傾向線。再者，塗黑 菱形之記號爲光阻膜1 0 1 ( PR )之灰化速度，虛線爲該傾 向線。另外，塗黑三角型之記號表示先前所述之選擇比， 一點鏈線表示該傾向線。在此，（比較例1 - 3 A )執行兩 次相同實驗，各記號表示該些實驗結果之平均値，錯誤槓 係以範圍表示該些實驗結果之値。 當觀看第5圖所示之SiN之鈾刻速度之傾向時，當自 (比較例1 -1 A )朝向（比較例1 - 3 A )升高處理容器2 0內 之壓力時，隨此S i N之触刻速度上升。然後，從（比較例 1 - 3 A ) (實施例1 - 2 )，蝕刻速度之變化幾乎持平，即 使提高處理容器20內之壓力，也不見蝕刻速度大幅上昇 。該傾向即使針對光阻膜1 0 1之灰化速度，當然也相同。 另外’針對選擇比，隨著提升處理容器2 0內壓力， S i N之蝕刻量比較多，從（比較例1 -1 A )到（比較例1 -3 A )選擇比漸漸下降。然後，從（比較例1 - 3 A )至（實 -23- 201126597 施例1 -2 )之範圍，選擇比幾乎持平。 第6圖（a )〜第6圖（c )係表示以與（比較例1 -1A〜1_3A)相同之條件將載置台3之溫度調節至9〇°C ( 比較例1-1B )〜（比較例1-3B )之各例中之光阻膜1〇1 及SiN基板之擴大縱剖面之照片。再者，第7圖（a )〜 第7圖（c )是表示以SF6之流量爲lOOsccm，02之流量 爲400sCCm (體積比1 : 4 )，與以（比較例1-1B〜1-3B )相同之條件，執行SiN基板之蝕刻（比較例1 -1 C ~ b 3 C )之結果的放大縱剖面之照片。 比較第6圖（a)〜第6圖（c)之（比較例1-1B〜1-3 B )和第7圖（a )〜第7圖（c )之（比較例1 -1C〜1 -3C )之實驗結果時，SF6和02之體積比爲1 : 4 (比較例 1-1C〜1-3C )中，觀察到比較明顯產生下切。對此，在（ 比較例1-1B)中，幾乎不會產生下切，再者，在（比較 例1-2B、1-3B )中，雖然觀察到一些下切的產生，但其 程度比（比較例1-2C、1-3C )小。 由此，可知藉由增加〇 2對S F 6之混合比率，比起〇 2 之混合比率小時，可以抑制下切產生之程度。然後，如此 —來應可以說即使針對處理容器20內之壓力設爲i33pa (lOOOmTorr)以上之（實施例1-1、1·2)，也有相同傾 向。 並且，在〇2對SF6之混合比率小於體積比1 : 6之區 域中，當將處理容器 20內之壓力提高至i33Pa ( lOOOmTorr )以上時，因電漿不安定，故不執行對應於該 -24- 201126597 壓力區域中之（比較例1 -1 c〜1 -3 C )之實驗。 (實驗2) 在LCD用之量產基板形成siN膜，在其上面塗布圖 案製作光阻膜1 Ο 1而作成被處理基板S，並執行SiN膜之 電漿蝕刻。在電漿蝕刻中，使用與電漿蝕刻裝置2同等構 成之蝕刻處理裝置，使SF6和02之混合氣體予以電漿化 而測量SiN之蝕刻速度（E/R )、光阻膜101之灰化速度 (A/R )、選擇比（光阻膜1 〇 1對S i n之蝕刻速度之灰化 速度比）。自高頻電源部48供給13.56MHz、3000W之高 頻電力3 0秒間。再者，載置台3之溫度調節成2 51。 A .實驗條件 (實施例2-1 )以1 OOsccm供給SF6，以600sccm供 給〇2(體積比1: 6)，處理容器20內之壓力設爲133Pa (1 OOOmTorr )。測量賦予第8圖所示之被處理基板S之 「1〜1 3」之數値的各點中，SiN膜之蝕刻量及光阻膜1 0 1 之灰化量。 (實施例2-2)除將處理容器20內之壓力設爲160Pa (1 200mTorr )之點外，其他設成與（實施例2-1 )相同 之條件。 (實施例2-3 )除將處理容器20內之壓力設爲200Pa (1 500mTorr )之點外，其他設成與（實施例2-1 )相同 之條件。 -25- 201126597 (比較例2- 1 )除將處理容器20內之壓力設I (8 00mTorr )之點外，其他設成與（實施例2-1 ) 條件。 B .實驗結果 在第9圖、第10圖表示（實施例2-1〜2-3) 較例2 - 1 )之結果。第9圖係表示繪圖被處理基板 每測量點上的SiN膜之蝕刻速度及蝕刻速度之面內 。第9圖之橫軸表示處理容器20內之壓力，上 [mTorr]單位表示，下段係以[Pa]單位表示。右側之 表示SiN之蝕刻速度[nm/min]，左側之縱軸係該鈾 之被處理基板S面內中之均勻性[±% ]。蝕刻速度 均勻性係根據以下（1 )式而算出。面內均勻性係 其値越小，蝕刻速度之偏差在被處理基板s之面內 面內均勻性[±%] =± [ { (E/R) MAX- (E/R) MIN} / { (E/R) N4AX+ (E/R) M I N) ] X 1 0 〇 ··· 但是，（E/R)MAX:蝕刻速度之最大値[nm/min] (E/R)min :触刻速度之最小値[nm/min] 第9圖中，空白圓圈記號係表示第8圖所示之 基板S之中央位置「7」之點的蝕刻速度，塗黑圓 係表示第8圖之中間位置「4、5、9、10」4點之 度之平均値。再者’第8圖所示之邊緣位置「1、； 、8、1 1、1 2、1 3」之8點的蝕刻速度係以錯誤槓 示最大値及最小値。星號係表示被處理基板S全f 〜1 3」之各點之蝕刻速度的平均値。然後，空白三 -26- 1 07Pa 相同之 、（比 S上之 均勻性 段係以 縱軸係 刻速度 之面內 表示係 越小。 (1) 被處理 圈記號 蝕刻速 、3、6 範圍表 I之「1 角記號 201126597 係表示被處理基板S全體之蝕刻速度之面內均勻性。 再者’第10圖係表示被處理基板S之平均之SiN膜 之蝕刻速度、光阻膜1 0 1之灰化速度及選擇比，橫軸、左 右縱軸及各記號以及各傾向線之意思係與第5圖相同。 針對（實施例2 - 1〜2 - 3 )、（比較例2 -1 )之結果， 首先當觀看如第9圖所示之SiN膜之蝕刻速度之傾向時， 即使針對中央位置、中間位置、邊緣位置以及全體平均中 之任一位置，從（比較例2-1 )到（實施例2-2 )隨著提 高處理容器20內之壓力，SiN膜之蝕刻速度也上升。該 係表示與使用SiN基板（實驗1)之各實施例、比較例之 結果相同之傾向。然後，將處理容器20內之壓力提升 2 00Pa ( 1 500mTorr)之（實施例2 - 3 )中，任一位置之測 量結果皆比（實施例2-2 )，蝕刻速度變小。 如此一來，使用LCD用之量產基板（實驗2)中，觀 察到蝕刻速度隨著提高處理容器2 0之壓力，描繪出在上 凸曲線之傾向。另外，針對蝕刻速度之面內均勻性，觀察 到與鈾刻速度相反，隨著提高處理容器20之壓力，描繪 出在下凸曲線之傾向。 該係表示在使S F6和02之體積比一定之條件下，於 (實施例2_2 )以下之壓力區域中隨著提高形成比較安定 之電漿的處理容器20內之壓力，也可以提升SiN膜之蝕 刻速度。再者，當處理容器20內之壓力超過（實施例2-2 )之値時，藉由〇2使電漿安定之效果相對變小’形成不 均勻之電漿，可以解釋SiN膜之蝕刻速度、面內均勻性應 -27- 201126597 同時下降。 接著，當觀看第10圖所示之（實施例2-1 (比較例2-1 )之結果時，如先前所述般，蝕刻 均値係對處理容器2 0內之壓力，描劃出上凸曲 針對光阻膜101之灰化速度，與處理容器20內 昇同時下降。其結果，光阻膜101對SiN膜之選 隨著提高處理容器2 0內之壓力而漸漸下降，從 2-2 )到（實施例2-3 )之範圍，選擇比幾乎持平 即使在第1 〇圖所示之結果中，於（實施例 下之壓力區域中形成比較安定之電漿且隨著提高 2〇內之壓力，選擇比隨SiN膜之蝕刻速度提升 處理容器20內之壓力當超過（實施例2-2 )時 形成安定之電漿，其結果可想選擇比不成爲持平 第11圖（a)〜第11圖（c)係表示（實施 2-3 )之各例中之光阻膜101及SiN膜之放大縱 。第1 1圖（a )、第1 1圖（b )所示之（實施例 )中，雖然不見下切產生，但在第11圖（c)所 施例2-3 )中觀察到些許下切的產生。但是，即. 施例2-3 )中，下切之產生的程度比起例如第7圍 第7圖（c)所示之（比較例1-1C〜1-3C)之時眞 當總合以上所示之（實驗1 )、（實驗2 ) ，在將SF6和〇2之體積比設爲1 : 6之時，隨著 容器20內之壓力，提高SiN之蝕刻速度。然後 處理容器20內之壓力時，SiN之蝕刻速度成爲 -2-3 )、 速度之平 線，另外 壓力之上 擇比，係 (實施例 〇 2-2 )以 處理容器 而下降， ，則難以 〇 例2 -1〜 剖面照片 2-1 ' 2-1 示之（實 ί在（實 (a)〜 小〇 之結果時 提高處理 ，當提高 持平（於 -28- 201126597 使用S i N基板（實驗1 )之時）’描畫出上凸曲線反而減 少（使用LCD之量產基板（實驗2)之時）。 由此可知，可以說執行S i N膜之電漿蝕刻的壓力環境 ’即使S i N之蝕刻速度停在高速度，或描畫出凸曲線而減 少之時，亦設爲取得蝕刻速度比較高之結果的1 3 3 P a ( lOOOmTorr)以上' 200Pa( 1500mTorr)以下之範圍爲佳 。再者，可想當SF6和02之體積比高過1 : 20時，SF6變 的太少即使升高壓力，蝕刻也幾乎不會進行。並且，最佳 之SF6和〇2之體積比應在例如1 : 6〜1 : 20左右之範圍 (實驗3 ) 使用與第4圖所示之電漿裝置2同等構成之蝕刻處理 裝置’使COF2和02之混合氣體予以電漿化，而以與（實 驗1 )相同條件測量SiN之蝕刻速度（E/R )、光阻膜1 0 1 之灰化速度（A/R )、選擇比（光阻膜1 〇 1對SiN之蝕刻 速度之灰化速度比）。 A.實驗條件 (實施例 3-1)以 300sccm 供給 COF2，以 600sccm 供給〇2 (體積比1:2)，處理容器20內之壓力設爲 160Pa ( 1200mTorr)。 (實施例3-2 )除將處理容器20內之壓力設爲24〇Pa (1 800mTorr )之點外，其他設成與（實施例3-1 )相同 -29- 201126597 之條件。 (實施例3-3 )除將處理容器20內之壓力設爲2 5 3 Pa (1 900mTorr )之點外，其他設成與（實施例3-1 )相同 之條件。 (比較例3-1)除將處理容器20內之壓力設爲l〇7Pa (800m To rr )之點外，其他設成與（實施例3- 1 )相同之 條件。 (實施例3 · 1〜3 · 3 )在第1 2圖、第1 3圖表示（實施 例3-1 )之結果。第12圖係表示SiN膜之蝕刻速度、光 阻膜1 〇 1之灰化速度及選擇比，橫軸、左右縱軸及各記號 以及各傾向線之意思係與第1 〇圖相同。 第1 3圖係表示SiN基板之中央位置之蝕刻速度及角 落部之蝕刻速度之偏差的圖示。第13圖之橫軸表示處理 容器20內之壓力，上段係以[mTorr]單位表示，下段係以 [Pa]單位表示，縱軸表示各位置中之蝕刻速度[nm/min]。 第1 3圖中，空白菱形記號係表示SiN基板之中央位置之 蝕刻速度，以錯誤槓所示之範圍係表示SiN基板之角落位 置之蝕刻速度之偏差範圍。 當觀看第12圖時，於使用COF2和02和混合氣體時 ，即使針對SiN之蝕刻速度、光阻膜1 〇 1之灰化速度中之 任一者，當從（比較例3 -1 )至（實施例3 -3 )提高處理 容器20內之壓力時，蝕刻速度及灰化速度幾乎與壓力上 升成比例上升，在實驗範圍內無觀察到該些速度持平之現 象。再者，當針對選擇比，提高處理容器20內之壓力時 -30- 201126597 ，選擇比之値平滑地變小，可以說係幾乎持平的變化。 該些應該係在執行實驗之壓力範圍中’ C0F2形成比 較安定之電漿，可以使壓力之上升反映在提升蝕刻速度之 結果。該係在第1 3圖，確認出由於在中央位置及角落中 之任一處，皆以幾乎相同蝕刻速度均勻進行蝕刻’故形成 有可在S i N基板面內均勻執行電漿蝕刻的安定電漿。 第14圖係表示（實施例3_2 )中之光阻膜1〇1及SiN 基板之放大縱剖面之照片，可知即使提高處理容器2 0內 之壓力，也不會產生下切，可以在SiN基板側形成錐面。 如第1 2圖、第1 3圖所不般’由（貫驗3 )之結果， 在將COF2和02之體積比設爲1 : 2之時，在壓力環境爲 133Pa ( lOOOmTorr )以上之範圍，可以藉由大槪 6000 A/min以上之高速執行SiN膜之蝕刻。然後，可想在 接近於實驗之 267Pa( 2000mTorr)以下之範圍中，蝕刻 速度不會急速下降，可以實現非常快之蝕刻速度。再者， 可想當C O F 2和Ο 2之體積比高過3 : 2 0時，C Ο F 2變的太 少即使升高壓力，蝕刻也幾乎不會進行。並且，最佳之 COF2和02之體積比應在例如1 : 2〜3 : 20左右之範圍。 【圖式簡單說明】 第1圖爲表示適用本實施型態所涉及之電漿蝕刻方法 之被處理基板之一例的縱斷側面圖。 第2圖爲表示在上述被處理基板上之TFT形成觸孔 之工程的縱斷側面圖。 -31 - 201126597 第3圖爲模式性表示在上述觸孔形成錐面之手法的說 明圖。 第4圖爲表示用以實施上述電漿蝕刻方法之電漿蝕刻 裝置之剖面側面圖。 第5圖爲表示電漿蝕刻所涉及之實驗結果之第1說明 圖。 第6圖爲表示電漿蝕刻所涉及之實驗結果之第2說明 圖。 第7圖爲表示電漿蝕刻所涉及之實驗結果之第3說明 圖。 第8圖爲表示上述實驗所使用之被處理基板中蝕刻速 度之測量點的說明圖。 第9圖爲表示電漿蝕刻所涉及之實驗結果之第4說明 圖。 第1 0圖爲表示電漿蝕刻所涉及之實驗結果之第5說 明圖。 第1 1圖爲表示電漿蝕刻所涉及之實驗結果之第6說 明圖。 第1 2圖爲表示電漿蝕刻所涉及之實驗結果之第7說 明圖。 第1 3圖爲表示電漿蝕刻所涉及之實驗結果之第8說 明圖。 第1 4圖爲表示電漿蝕刻所涉及之實驗結果之第9說 明圖。 -32· 201126597 【主要元件符號說明】 S :被處理基板 la: T F T 部 1 b :接觸部 1 〇 1 :光阻膜 1 0 2 :開口部 1 0 3 :觸孔 1 7 :鈍化膜 2 :電漿蝕刻裝置 3 :載置台 4 :上部電極 45 :蝕刻氣體供給部 46 :氧供給部 51 :真空泵 5 1 1 :壓力調節閥 6 :控制部 -33-Inside the processing container 20, a mounting table 3 on which the substrate to be processed S -12 - 201126597 is placed is disposed. The mounting table 3 is disposed on the bottom surface of the electrical performance container 20, and functions as a working electrode that functions as a lower electrode. Further, the peripheral portion and the side surface of the mounting table 3 are covered with a slurry, which is uniformly formed on the mounting table 3 by, for example, a ceramic material focus ring 33. The focus ring 33 functions to adjust the plasma state of the region to be treated, for example, to concentrate the plasma on the substrate S and to increase the etching rate. In the present embodiment, the mounting region of the substrate S to be processed is formed across, for example, the upper surface thereof, and a portion of the upper surface of the focus ring 33 around it is disposed on the mounting table 3 to be disposed in the outside without being transported. An intersection 34 of the substrate S to be processed is executed between the apparatus and the mounting table 3. The lift pins 34 are connected to the elevating mechanism 35, and are expandable and contractible from the load surface, and the workpieces S can be lifted and lowered 36 in order to place the processing containers 20 between the mounting areas of the substrate S to be processed. Keep the vacuum and cover the lifting and lowering body. A flat upper electrode 4 is provided above the one mounting table 3 so as to be in contact with the mounting table 3, and the upper electrode is formed on the gusset upper electrode base 41. The upper electrode quadrupole bases 41 are made of, for example, aluminum and are electrically connected to each other. The upper surface of the upper seat 4 1 is attached to the ceiling by the insulating member 4 1 1 and is in a state in which the self-processing container 20 is electrically floated. A high-frequency power supply unit 48 for generating plasma is connected to the susceptor 41, and is connected to the slab, and is used as a galvanic material for electrically forming the poly-substrate S to be processed, and the "tableting area of the mounting table 3" is placed. The position of the lifting table 3 shown in the figure is shown. In the figure, the upper surface of the r pin 3 4 is supported by the upper electrode and the upper electrode of the upper electric electrode electrode 20 is the upper part of the electrode-13 - 201126597. The cathode electrode functions as a cathode. The space surrounded by the upper electrode base 4 1 and the upper electrode 4 constitutes a gas diffusion space 42 for etching gas. Hereinafter, the upper electrode 4 and the upper electrode base 41 are provided. The gas shower head 40 is generally provided. The gas supply path 43 is provided in the ceiling portion of the processing container 20 so as to be connected to the diffusion space 42, and the gas supply path 43 is divided into two, and the etching gas supply path 43 on one side is provided. 1 is connected to the etching gas supply unit 45, and the other oxygen supply path 43 2 is connected to the oxygen supply unit 46. The etching gas supply unit 45 stores SF6 for etching the SiN film of the substrate S to be processed (hereinafter) , the record is SF6), The SF 6 is supplied to the processing container 20 in a state of a gas. Further, the oxygen supply unit 46 is stored to stabilize the plasma generated in the processing container 20, and the ashing speed of the photoresist film 10 is adjusted. On the other hand, the oxygen generated by the undercut (hereinafter referred to as 〇2) is suppressed, and the 02 mixed with SF6 is supplied to the processing container 20. The etching gas supply unit 45, the oxygen supply unit 46, and the diffusion space 42 are provided. A flow rate adjusting unit 44 composed of, for example, a mass flow controller is provided between each of the supply passages 43 1 and 432. The flow rate adjusting unit 44 is provided with an SF 6 for adjusting the processing container 20 according to an instruction from a control unit 6 to be described later. The supply amount of Ο 2 serves to adjust the mixing ratio of SF 6 and Ο 2. In the plasma etching method according to the present embodiment, the flow rate adjusting portion 44 can mix SF6 and 02 into, for example, 1:6. The volume ratio of the range of 1:20 or less is supplied to the processing container 20. When a specific example is given, in this example, the flow rate adjusting unit 44 is controlled to adjust the flow rate of SF6 - 14 - 201126597, for example. To l〇〇sccm(sc Cm: ml/min (0 ° C, 1 atmosphere) The same as the above) 'Adjust 〇 2 to 6,000 sccm, and mix the mixture into a volume ratio of 1: 6 to the processing container 20. Thus, When the mixed gas is supplied to the diffusion space 4 2 , the mixed gas is supplied to the processing space above the substrate S to be processed via the gas supply hole 47 provided in the upper electrode 4, and is plasmaized to be processed. The substrate S is subjected to etching treatment. Further, one end side of the exhaust passage 24 in the environment in the exhaust gas treatment container 20 is connected to the bottom surface of the processing container 20, and a vacuum pump 51 is connected to the other end side via the pressure regulating valve 511. The gas system in the processing vessel 20 is exhausted from the exhaust passage 24 toward the detoxification device 52 that is common to the factory, for example. Here, in the conventional plasma etching method, the pressure in the processing container 20 is reduced to, for example, less than 1 3 3 P a (100 m Torr ), for example, 13.3 Pa (l〇〇mTorr). The processing of the si N film is performed by supplying, for example, SF 6 without mixing Ο 2 in the processing container 20 in the high vacuum environment. In such a high vacuum environment, even if the large-sized processing container 20' is plasma-stabilized as in this example, there is a case where the undercut can be suppressed. However, there is a problem that the etching speed of the 'S iN film in a high vacuum environment is slow and a sufficient amount of processing cannot be obtained. Further, when the pressure in the processing container 20 is increased while the SF 6 is supplied alone, it is difficult to form a stable plasma, and the possibility of undercut is remarkably high. Here, the conventional plasma etching apparatus is not designed to perform etching under a relatively low vacuum pressure environment of, for example, 1 33 Pa (1 〇〇〇mT〇rr ) or more. Even for a vacuum pump, a high vacuum environment can be used. - 201126597 Vacuum pumps such as turbomolecular pumps with high prices. In this regard, in the plasma etching method according to the present embodiment, as described above, the 〇 6 is mixed in the range of, for example, a volume ratio of 1:6 to 1:20, and thus even in the pressure comparison. In a high environment, plasma is also formed in a stable manner, and the ratio of the etching rate of the SiN film to the ashing speed of the photoresist film 1 〇1 can be adjusted to make it difficult to produce an undercut state. Since the pressure environment is formed in the processing container 20, the vacuum pump 51 and the pressure regulating valve 51 in the present embodiment adjust the opening of the pressure regulating valve 5 1 1 according to the indication of a pressure gauge (not shown). The degree of pressure in the processing container 20 can be adjusted to, for example, i33 Pa (1000 mTorr) or more in the range of '200 Pa (1500 mTorr) or less, for example, l33 Pa (100 mTorr). In this way, the vacuum pump 51 can not produce a high vacuum state like a turbo molecular pump, but a cheaper dry pump, because the plasma uranium engraving can be performed in a low vacuum state compared to the conventional high vacuum environment. Composition. Further, the plasma etching apparatus 2 is connected to the control unit 6. The control unit 6 is constituted by a computer including, for example, a CP U and a program (not shown), and the operation of the electric lithography device 2 is programmed, that is, the substrate S to be processed is carried into the processing container 20, and After adjusting the supply amount of SF6 and 〇2 to the processing container 20, the supply ratio, and the pressure in the processing container 20, the etching gas (mixed gas of SF6 and 02) is plasma-formed to form a substrate S for the substrate to be processed. A step (command) group of control or the like involved in the operation from the etching process to the time of carrying out the transfer. The program is stored in a memory medium such as a hard disk, a CD, a magneto-optical disk, a memory card, etc., and has since been installed on a computer by An-16-201126597. Hereinafter, the operation of the etching processing apparatus 2 according to this embodiment will be described. First, when the user selects the process recipe of the desired plasma etching process and inputs it to the control unit 6 via the operation unit (not shown), the control unit 6 outputs the respective parts of the etching processing device 2 according to the process recipe. The control signal is such that a specific plasma etching process is performed on the substrate S. First, the gate valve 23 is opened, and an external transfer means (not shown) is formed on the surface as shown in Fig. 2(a). The substrate S to be processed of the resist film 1 is carried into the processing container 20, and the resist film 1〇1 is provided with an opening portion 102 corresponding to the contact hole 103, and is transported to a receiving position above the mounting table 3. When the substrate S to be processed reaches the receiving position, the lift pin 34 is raised to transport the substrate S to be processed from the transport means to the lift pin 34, and the transport means is returned to the outside of the processing container 20, and the lift pin 34 is lowered. The substrate S to be processed is placed on the placement area. Then, when the loading/unloading port 2 2 is closed, the vacuum pump 51 is operated, and the pressure regulating valve 511 is used to adjust the inside of the processing container 20 to a pressure of, for example, 133 Pa (10 Torr), and the flow regulating portion 44' is utilized. The flow rate adjustment is performed so that the flow rate of the SF6 becomes 100 seccm 'the flow rate of 〇2 becomes 60 〇Sccm (volume ratio 1:6), and the two gases are supplied from the etching gas supply unit 45 and the oxygen supply unit 46 to the processing container 20 〇 SF6 and 〇2 are sufficiently mixed in the gas supply path 43 and the diffusion space 42 to be discharged into the processing container 2 through the gas supply hole 47. After -17-201126597, high-frequency power is supplied from the high-frequency power supply unit 48 to the space above the upper electrode substrate S to form a plasma, and the SiN plasma is etched. Here, SF6 is an insulating gas, and it is difficult to form a uniform plasma in the processing container 20 of the substrate S to be processed, and 〇2, which has an effect of promoting the dissociation of SF6, is sf6 and the product ratio. By mixing at a ratio of 1:6 to 1:20, a uniform plasma can be formed on the entire surface of the device 20. This is to visually confirm the state of the plasma in the container 20, and it is confirmed even in the later-described embodiment. In addition, since 〇2 does not have the ability to etch the SiN film, the etching rate of the SiN film may also become slow when the mixing ratio is used. In this example, the pressure in the processing container 20 is set to 1 3 3 Pa (100 Torr) to 200 Pa (1500 mTorr) t 匕 In a high environment, even when the mixing ratio of 〇2 is increased, the number of molecules of the processing container SF 6 is smaller or more increased. However, in the mixed gas mixed with 0 2, as described above, since the plasma is formed, most of the active species of SF 6 are formed, which contributes to the improvement of the etching, even for the point of improving the etching speed of the SiN film. The experiments in the examples are confirmed. Furthermore, although the 02 which is mixed with the SF6 has no etching SiN film, since it has the ability to ash the photoresist film 1 〇1, it can complement the etching rate of the SiN film, and also improve the photoresist film. gray. As a result, the SiN film and the photoresist film 101 are, for example, equally cut, and the film is stored in a large size, but the body of the film 2 is processed and processed. The experiment is also proposed. However, for example, after the pressure of 20, the speed at stability. In the latter, the ability to increase the speed does not occur. -18- 201126597 The SiN film is formed under the cut. The shape control of the contact hole 1 〇3 can be performed well. Even for this point, it was confirmed by experiments in the examples described later. Further, when the signal line film constituting the source electrode 161 or the drain electrode 162 includes Mo as in the Mo/Al/Mo laminated film of the stacked layers Mo and A1, the SF6 is used to etch Mo, and the SiN film. The selection ratio (the ratio of the SiN film to the etching rate of Mo) becomes important. However, by increasing the mixing ratio of 〇 2, the selection ratio can be increased. The plasma gas system is lowered in the processing container 20 to reach the substrate S to be processed, and an etching treatment is performed on the surface thereof. Then, the gas conveys the surface of the substrate S to be processed, flows to the peripheral portion side, passes through the space between the focus ring 33 and the processing container 20, flows into the exhaust path 24, and is exhausted to the outside of the processing container 20. In this way, according to the process recipe, when the plasma etching process is performed for a specific time, the supply of the SF6, 02 or the high-frequency power is stopped, and the pressure in the processing container 20 is returned to the original state, which is opposite to the time of loading. In this order, the substrate S to be processed is transported from the mounting table 3 to the outside by means of the transport means, and is carried out from the plasma etching apparatus 2 to complete a series of etching processes. According to the plasma etching treatment method according to this embodiment, the following effects are obtained. By performing plasma etching using a mixed gas of SF6 and 02, a stable plasma can be obtained even under a high pressure environment of 1 3 3 P a (100 nm Torr), and high-speed etching can be performed. SiN film. Furthermore, by adjusting the gas containing the ability to ash the photoresist film 101, the ratio of the etching rate of the SiN film to the ashing speed of the photoresist film 1 can be adjusted, and the opening area can be gradually reduced from the upper portion to the lower portion. The opening portion 1 02-19 - 201126597 The shape is transferred from the photoresist film 101 to the si N film, and good shape control can be performed for forming the contact hole 10 3 . Furthermore, since the etching of the SiN film can be performed in a vacuum environment lower than in the past, it is possible to reduce the electricity by using a relatively low-priced dry pump or the like instead of forming a turbomolecular pump in a high vacuum environment as the vacuum pump 5 1. The cost of the apparatus of the slurry etching apparatus 2. Next, a plasma processing method according to a second embodiment of the present invention will be described. The plasma processing method according to the second embodiment can be carried out by a plasma etching apparatus 2 having almost the same configuration as that shown in Fig. 4, and the following points are different. In the plasma etching apparatus 2 according to the second embodiment, difluorinated carbonyl (COF2) having a warming coefficient almost equal to that of carbon dioxide is used as an etching gas for etching the SiN film, and COF2 is stored in the etching gas supply portion 45. To replace SF6. Further, the flow rate adjusting unit 44 of the present embodiment supplies the mixed gas in which COF 6 and 02 are mixed to a volume ratio of, for example, a range of 1:2 or more and 3:20 or less, to the processing container 20. The vacuum pump 51 and the pressure regulating valve 5 1 1 according to the second embodiment are provided with an opening degree of the pressure regulating valve 511 according to an instruction of a pressure gauge (not shown), whereby the pressure in the processing container 20 can be adjusted. The environment is adjusted to, for example, a capacity of 133 Pa (1 OOO mTorr) or more and 2 6 7 P a (200 nm Torr) or less. Under the conditions described above, even when the mixed gas of COF2 and 02 is plasma-treated to perform plasma etching of the substrate S, it is possible to obtain stable plasma formation, increase the etching rate of the SiN film, and suppress the lower cut production. -20- 201126597 The shape of the contact hole 103 is controlled to prevent the signal line film (source electrode 161, drain electrode 162) from collapsing the TFT portion 1a and the contact portion 1b at one time, due to the collapse of A low vacuum pump is used to reduce various effects such as equipment cost. Here, the mixed gas discharged from the processing container 20 is captured by the detoxification device 52 to capture most of the COF2 contained in the same gas, and the remaining crucible 2 is released to the atmosphere. However, since the capture efficiency of COF2 in the abatement device 52 is not 100%, only a small amount of COF2 is released to the atmosphere. Even in such a case, as described above, since COF2 is a substance having a warming coefficient equal to that of carbon dioxide, the burden on the environment can be reduced. The plasma etching method according to the first and second embodiments described above is not limited to the case where the TFT portion 1 a and the contact portion 1 b on the substrate S to be processed are once etched as shown in FIG. 1 . It can also be applied to when two regions are etched individually. Further, the plasma processing method of adjusting the pressure of the processing container 20 to 133 Pa (1 OOO mTorr) or more to generate plasma may be applied to the ashing of the photoresist film 1 by supplying only 〇2 to the processing container 20. 0 1 , a plasma ashing method for removing the substrate S to be processed. In the past, ashing was performed in a pressure environment higher than 135 Pa (100 Torr), which is performed by plasma ashing, whereby damage to the device formed on the substrate S to be processed was low, and high-speed ashing treatment can be performed. [Examples] (Experiment 1) -21 - 201126597 Using a etching treatment apparatus having the same configuration as that of the plasma etching apparatus 2 described in Fig. 4, a mixed gas of SFs and 〇2 was plasma-formed to form a surface pattern. Etching of the SiN substrate of the photoresist film 〇1, measuring the etching rate (E/R) of SiN, the ashing speed (a/R) of the photoresist film, and the selection ratio (etching of the SiN by the photoresist film 101) The speed of ashing speed ratio). The high frequency power supply unit 48 supplies high frequency power of 13.56 MHz and 3000 W for 30 seconds. Further, the temperature of the mounting table 3 was adjusted to 251. A. Experimental conditions (Example 1-1) SF6 was supplied at 100 sccm, 〇2 (volume ratio 1:6) was supplied at 600 sccm, and the pressure in the treatment vessel 20 was set to 133 Pa (100 Torr). (Example 1-2) The same conditions as in (Example 1-1) were set except that the pressure in the treatment container 20 was set to 160 Pa (1 200 mT 〇 rr ). (Comparative Example 1-1A) The same conditions as in (Example 1-1) were set except that the pressure in the processing container 20 was set to 2 6 · 7 P a (200 m T 〇 r r ). (Comparative Example 1-2A) The same conditions as in (Example 1-1) were set except that the pressure in the processing container 20 was set to 53.3 Pa (400 mTorr). (Comparative Example 1-3A) The same conditions as in (Example 1-1) were set except that the pressure in the processing container 20 was 107 Pa (800 mTorr). -22- 201126597 B. Experimental results The results of (Examples 1 -1 to 1 - 2 ) and (Comparative Examples 1 - 1 A to 1-3A) are shown in Fig. 5. The horizontal axis of Fig. 5 indicates the pressure in the processing container 20, and the number of the upper stage is expressed in units of [m T 〇 r r ], and the number of the lower stage is expressed in units of [P a]. The vertical axis on the right side indicates the etching rate of S i N or the ashing speed of the photoresist film 10 1 [nm / mi η ] 'The vertical axis on the left side indicates the selection ratio [_ ], that is, the photoresist film 101 to SiN The ratio of the ashing speed of the etching rate. The mark of the blank diamond shown in Fig. 5 indicates the etching rate of S i N in each of the examples and the comparative examples, and the solid line indicates the tendency line. Further, the black diamond-shaped mark is the ashing speed of the photoresist film 1 0 1 (PR), and the broken line is the inclined line. In addition, the black triangle type symbol indicates the selection ratio previously described, and the one-point chain line indicates the tendency line. Here, (Comparative Example 1-3 A) two identical experiments were performed, each mark indicating the average enthalpy of the results of the experiments, and the error bar indicates the enthalpy of the results of the experiments by the range. When the tendency of the uranium engraving speed of SiN shown in Fig. 5 is observed, when the pressure in the processing container 20 is raised from (Comparative Example 1-1 A) toward (Comparative Example 1-3 A), The etch rate of i N increases. Then, from (Comparative Example 1 - 3 A ) (Example 1-2), the change in the etching rate was almost flat, and even if the pressure in the processing container 20 was increased, the etching rate was not significantly increased. This tendency is of course the same even for the ashing speed of the photoresist film 101. Further, with respect to the selection ratio, the amount of etching of S i N was relatively large as the pressure in the processing container 20 was increased, and the selection ratio was gradually decreased from (Comparative Example 1-1 A) to (Comparative Example 1-3 A). Then, from the range of (Comparative Example 1-3 A) to (Actual -23-201126597 Example 1-2), the selection ratio was almost the same. 6(a) to 6(c) show that the temperature of the mounting table 3 is adjusted to 9 〇 ° C (Comparative Example 1-1B) to the same conditions as (Comparative Example 1-1A to 1_3A). Photograph of the enlarged longitudinal section of the photoresist film 1〇1 and the SiN substrate in each of Comparative Examples 1-3B). Further, Fig. 7(a) to Fig. 7(c) show that the flow rate of SF6 is lOOsccm, the flow rate of 02 is 400 sCCm (volume ratio of 1:4), and (Comparative Example 1-1B to 1-3B) Under the same conditions, a photograph of an enlarged longitudinal section of the result of etching of the SiN substrate (Comparative Example 1-1 C ~ b 3 C ) was performed. Comparing Figs. 6(a) to 6(c) (Comparative Examples 1-1B to 1-3B) and Figs. 7(a) to 7(c) (Comparative Example 1-1 C~1) In the experimental results of -3C), in the volume ratio of SF6 to 02 of 1:4 (Comparative Examples 1-1C to 1-3C), it was observed that the undercut was more apparent. On the other hand, in (Comparative Example 1-1B), almost no undercut occurred, and in (Comparative Examples 1-2B and 1-3B), although some undercuts were observed, the degree was compared (comparison Example 1-2C, 1-3C) is small. From this, it is understood that by increasing the mixing ratio of 〇 2 to S F 6 , the degree of undercut generation can be suppressed as compared with the case where the mixing ratio of 〇 2 is small. Then, it can be said that even if the pressure in the processing container 20 is set to i33pa (100OmTorr) or more (Examples 1-1 and 1-2), the same tendency is obtained. Further, in the region where the mixing ratio of 〇2 to SF6 is smaller than the volume ratio of 1:6, when the pressure in the processing container 20 is raised to i33Pa (100OmTorr) or more, since the plasma is unstable, the corresponding one is not performed. 24- 201126597 Experiment in the pressure zone (Comparative Example 1-1 c~1 -3 C). (Experiment 2) A SiN film was formed on a mass-produced substrate for LCD, and a photoresist film 1 Ο 1 was formed thereon to form a substrate S to be processed, and plasma etching of the SiN film was performed. In the plasma etching, an etching treatment device having the same configuration as that of the plasma etching apparatus 2 is used to plasma-mix the mixed gas of SF6 and 02 to measure the etching rate (E/R) of SiN and the ashing of the photoresist film 101. Speed (A/R), selection ratio (ashing speed ratio of etching speed of photoresist film 1 〇1 to S in). The high frequency power supply unit 48 supplies a high frequency power of 13.56 MHz and 3000 W for 30 seconds. Furthermore, the temperature of the mounting table 3 is adjusted to 2 51. A. Experimental conditions (Example 2-1) SF6 was supplied at 100 sccm, 〇2 (volume ratio 1:6) was supplied at 600 sccm, and the pressure in the processing vessel 20 was set to 133 Pa (1 OOO mTorr). The amount of etching of the SiN film and the amount of ashing of the photoresist film 10 1 at each point of the number "1 to 1 3" of the substrate S to be processed shown in Fig. 8 were measured. (Example 2-2) The same conditions as in (Example 2-1) were set except that the pressure in the processing container 20 was 160 Pa (1 200 mTorr). (Example 2-3) The same conditions as in (Example 2-1) were set except that the pressure in the processing container 20 was set to 200 Pa (1 500 mTorr). -25-201126597 (Comparative Example 2 - 1) The conditions were set to (Example 2-1) except that the pressure in the processing container 20 was set to 1 (800 mTorr). B. Experimental results The results of Comparative Example 2 - 1 are shown in Fig. 9 and Fig. 10 (Examples 2-1 to 2-3). Fig. 9 is a view showing the etching speed and etching speed of the SiN film at each measurement point on the substrate to be processed. The horizontal axis of Fig. 9 indicates the pressure in the processing container 20, which is expressed in units of [mTorr], and the lower stage is expressed in [Pa] units. The right side indicates the etching rate [nm/min] of SiN, and the vertical axis on the left side is the uniformity [±%] in the plane of the substrate S of the uranium. The etching rate uniformity was calculated according to the following formula (1). The in-plane uniformity is the smaller the enthalpy, and the variation of the etching speed is in-plane in-plane uniformity of the substrate s to be processed [±%] = ± [ { (E/R) MAX- (E/R) MIN} / { (E/R) N4AX+ (E/R) MIN) ] X 1 0 〇··· However, (E/R)MAX: maximum etch rate [nm/min] (E/R)min: etch rate Minimum 値 [nm/min] In Fig. 9, the blank circle symbol indicates the etching speed at the point "7" of the center position "S" of the substrate S shown in Fig. 8, and the black circle indicates the middle position of Fig. 8" 4, 5, 9, 10" The average of 4 points. Further, the etching speed at 8 o'clock of the edge positions "1,; 8, 8, 1 2, 2 2, 1 3" shown in Fig. 8 is the maximum 値 and the minimum 以 in the error bar. The asterisk indicates the average 値 of the etching speed of each point of the substrate S to be f −1 3′′. Then, the blanks are the same as the 3-26- 1 07Pa (the smaller than the in-plane representation of the uniformity of the vertical axis on the S axis). (1) The processed ring mark etching rate, 3, 6 range table The "1 corner mark 201126597" of I indicates the in-plane uniformity of the etching rate of the entire substrate S to be processed. Further, Fig. 10 shows the etching rate of the SiN film which is the average of the substrate S to be processed, and the photoresist film 10 1 The ashing speed and the selection ratio, the horizontal axis, the left and right vertical axes, and the respective symbols and the respective trend lines are the same as those in Fig. 5. For (Embodiment 2 - 1 to 2 - 3 ), (Comparative Example 2-1) As a result, first, when viewing the tendency of the etching rate of the SiN film as shown in Fig. 9, even from the center position, the intermediate position, the edge position, and the overall average, from (Comparative Example 2-1) (Example 2-2) The etching rate of the SiN film also increased as the pressure in the processing container 20 was increased. This shows the same tendency as the results of the respective examples and comparative examples using the SiN substrate (Experiment 1). , the pressure in the processing container 20 is increased by 200 Pa (1,500 mTorr). In Example 2 - 3), the measurement result at any position was higher than that of (Example 2-2), and the etching rate became small. Thus, in the mass production substrate for LCD (Experiment 2), the etching rate was observed. As the pressure of the processing vessel 20 is increased, the tendency of the upper convex curve is drawn. In addition, for the in-plane uniformity of the etching speed, it is observed that the etching speed is opposite to that of the uranium, and the pressure of the processing container 20 is increased. The tendency of the convex curve. This system shows that under the condition that the volume ratio of S F6 and 02 is constant, in the pressure region below (Example 2_2), the pressure in the processing container 20 which forms the relatively stable plasma is increased. It is also possible to increase the etching rate of the SiN film. Further, when the pressure in the processing container 20 exceeds ((2-2), the effect of the plasma stabilization is relatively small by the 〇2, forming an uneven electricity. The slurry can explain that the etching rate and in-plane uniformity of the SiN film should decrease simultaneously from -27 to 201126597. Next, when viewing the results of Example 2-1 (Comparative Example 2-1) as shown in Fig. 10, Etched to the processing vessel 2 as previously described The pressure within 0 indicates that the ashing speed of the upper convex curvature against the photoresist film 101 is decreased simultaneously with the inner rise of the processing container 20. As a result, the selection of the photoresist film 101 for the SiN film is improved within the processing container 20 The pressure gradually decreases, from 2-2) to (Example 2-3), the selection ratio is almost the same, even in the results shown in Fig. 1, the formation is relatively stable in the pressure region under the embodiment. With the increase of the pressure within 2 Torr, the plasma is selected to form a stable plasma when the pressure in the processing container 20 is increased as compared with the etching rate of the SiN film. (Example 2-2), the result is that the ratio can be selected. It is not shown that the eleventh drawing (a) to the eleventh figure (c) show the enlarged longitudinal direction of the photoresist film 101 and the SiN film in each of the examples (embodiments 2-3). In (Embodiment) shown in Fig. 1 (a) and Fig. 1 (b), although no undercut occurred, a slight undercut was observed in Example 2-3 of Fig. 11(c). produce. However, in the case of Example 2-3), the degree of undercutting is greater than the sum of the times when, for example, the seventh circumference (Fig. 7(c)) (Comparative Examples 1-1C to 1-3C) As shown (Experiment 1) and (Experiment 2), when the volume ratio of SF6 to 〇2 was set to 1:6, the etching rate of SiN was increased with the pressure in the container 20. Then, when the pressure in the container 20 is processed, the etching rate of SiN becomes -2-3), the flat line of the speed, and the pressure is selected on the basis of the ratio (Example 〇2-2) to lower the processing container, which is difficult. Example 2 -1 ~ Section photo 2-1 '2-1 shows (actually (in real (a) ~ small 〇 results when improving processing, when raising flat (on -28- 201126597 using S i N substrate ( At the time of Experiment 1), 'the upper convex curve was reduced instead (when the mass production substrate of the LCD was used (Experiment 2)). It can be said that the pressure environment for performing the plasma etching of the SiN film can be said to be even S When the etching speed of i N is stopped at a high speed or the convex curve is reduced, it is also preferable to obtain a range of 1 3 3 P a (10000 Torr) or more and less than 200 Pa (1500 mTorr) as a result of a relatively high etching rate. Furthermore, it is conceivable that when the volume ratio of SF6 and 02 is higher than 1:20, SF6 becomes too small, even if the pressure is raised, the etching hardly proceeds. And, the volume ratio of the best SF6 and 〇2 should be In the range of, for example, 1:6 to 1:20 (Experiment 3), the same configuration as the plasma device 2 shown in Fig. 4 is used. The etching treatment device 'sintered the mixed gas of COF 2 and 02, and measured the etching rate (E/R ) of SiN and the ashing speed of the photoresist film 10 1 under the same conditions as (Experiment 1) (A/ R), selection ratio (the ratio of ashing speed of the etching speed of the photoresist film 1 〇1 to SiN). A. Experimental conditions (Example 3-1), COF2 was supplied at 300 sccm, and 〇2 was supplied at 600 sccm (volume ratio 1: 2) The pressure in the processing container 20 is set to 160 Pa (1200 mTorr). (Example 3-2) Except that the pressure in the processing container 20 is 24 〇Pa (1 800 mTorr), the other is set to Example 3-1) The same condition as -29-201126597. (Example 3-3) Except that the pressure in the processing container 20 was set to 2 5 3 Pa (1 900 mTorr), the other was set to (Example 3) -1) The same conditions. (Comparative Example 3-1) The same conditions as in (Example 3 - 1) were set except that the pressure in the processing container 20 was set to 10 〇 7 Pa (800 m To rr ). (Example 3·1 to 3·3) The results of (Example 3-1) are shown in Fig. 1 and Fig. 13. Fig. 12 shows the etching rate of SiN film, and photoresist film 1 〇1. Ashing speed The selection ratio, the horizontal axis, the left and right vertical axes, and the respective symbols and the respective trend lines are the same as those in the first drawing. Fig. 3 is a view showing the difference between the etching speed at the center position of the SiN substrate and the etching speed at the corner portion. Show. The horizontal axis of Fig. 13 indicates the pressure in the processing container 20, the upper stage is expressed in [mTorr] units, the lower stage is expressed in [Pa] units, and the vertical axis indicates etching speed [nm/min] in each position. In Fig. 3, the blank diamond symbol indicates the etching speed at the center of the SiN substrate, and the range indicated by the error bar indicates the deviation range of the etching speed at the corner position of the SiN substrate. When viewing FIG. 12, when COF2 and 02 and the mixed gas are used, even if the etching rate for SiN or the ashing speed of the photoresist film 1 〇1 is from (Comparative Example 3-1) to (Example 3-4) When the pressure in the processing container 20 was raised, the etching rate and the ashing speed increased almost in proportion to the pressure rise, and the phenomenon that the speeds were not observed was observed in the experimental range. Further, when the pressure in the processing container 20 is raised for the selection ratio, -30-201126597, the selection is smoothly smaller than that, and it can be said that the change is almost flat. These should be in the pressure range in which the experiment is performed. 'C0F2 forms a relatively stable plasma, which can reflect the increase in pressure as a result of increasing the etching rate. In the first graph, it is confirmed that the etching is performed uniformly at almost the same etching speed at any of the central position and the corners, so that the stability of plasma etching can be uniformly performed in the surface of the SiN substrate. Plasma. Fig. 14 is a photograph showing an enlarged longitudinal section of the photoresist film 1〇1 and the SiN substrate in (Example 3_2), and it is understood that even if the pressure in the processing container 20 is increased, no undercut occurs, and the SiN substrate side can be formed. Form a tapered surface. As shown in Fig. 12 and Fig. 3, the result of (test 3), when the volume ratio of COF2 and 02 is 1:2, the pressure environment is 133 Pa (10000 mTorr) or more. The etching of the SiN film can be performed at a high speed of more than 6000 A/min. Then, it is conceivable that the etching rate does not drop sharply in the range of 267 Pa (2000 mTorr) or less, which is close to the experiment, and a very fast etching speed can be realized. Further, it is conceivable that when the volume ratio of C O F 2 and Ο 2 is higher than 3 : 2 0, C Ο F 2 becomes too small, and even if the pressure is raised, the etching hardly proceeds. Also, the optimum volume ratio of COF2 and 02 should be in the range of, for example, 1: 2 to 3:20. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal side view showing an example of a substrate to be processed to which the plasma etching method according to the present embodiment is applied. Fig. 2 is a longitudinal side view showing a process of forming a contact hole in a TFT on the substrate to be processed. -31 - 201126597 Fig. 3 is an explanatory view schematically showing a method of forming a tapered surface in the above-mentioned contact hole. Fig. 4 is a cross-sectional side view showing a plasma etching apparatus for carrying out the above plasma etching method. Fig. 5 is a first explanatory view showing the results of experiments involving plasma etching. Fig. 6 is a second explanatory view showing the results of experiments involving plasma etching. Fig. 7 is a third explanatory view showing the results of experiments involving plasma etching. Fig. 8 is an explanatory view showing measurement points of etching speed in the substrate to be processed used in the above experiment. Fig. 9 is a fourth explanatory view showing the results of experiments involving plasma etching. Fig. 10 is a fifth explanatory diagram showing the experimental results involved in plasma etching. Fig. 1 is a sixth explanatory diagram showing the results of experiments involving plasma etching. Fig. 1 is a seventh explanatory diagram showing the experimental results involved in plasma etching. Fig. 1 is an eighth explanatory diagram showing the experimental results involved in plasma etching. Fig. 14 is a ninth explanatory diagram showing the experimental results involved in plasma etching. -32· 201126597 [Description of main component symbols] S : substrate to be processed la: TFT portion 1 b : contact portion 1 〇 1 : photoresist film 1 0 2 : opening portion 1 0 3 : contact hole 1 7 : passivation film 2 : Plasma etching apparatus 3: mounting table 4: upper electrode 45: etching gas supply unit 46: oxygen supply unit 51: vacuum pump 5 1 1 : pressure regulating valve 6: control unit - 33-