200524040 (1) 九、發明說明 【發明所屬之技術領域] 本發明係有關low-k膜用蝕刻液及使用該蝕刻液之 1 〇 w - k膜用蝕刻液及蝕刻方法。 【先前技術】 近年來’層間絕緣膜使用 Coral、Aourora、Black Diamond 等之 low-k 材料。 此等之l〇w-k材料，於晶片表面製膜時附著於晶片斜 面部或裏面等不需要之地方，需要以蝕刻將其去除。200524040 (1) IX. Description of the invention [Technical field to which the invention belongs] The present invention relates to an etchant for a low-k film and an etchant and a etching method for a 100 w-k film using the same. [Prior art] In recent years, low-k materials such as Coral, Aourora, and Black Diamond have been used for the interlayer insulation film. These 10w-k materials are attached to unnecessary portions of the wafer such as the oblique portion or the inside of the wafer during film formation, and need to be removed by etching.
Low-k膜已知有使用乾蝕刻去除之技術，以濕蝕刻迅 速去除之触刻液尙未未知曉。 有關濕蝕刻，如日本特開2000-164585號公報、曰本 特開2000-164586號公報、日本特開2000-246378號公報 所揭示爲蝕刻S i Ο 2或摻雜氧化膜 （B S G、B P S G、P S G等） 之蝕刻液，對Llow-k膜之蝕刻液則未開示。 本發明係提供，爲實用上充分迅速的將low _k膜濕蝕 刻之蝕刻液及蝕刻方法爲目的。 【發明內容】 [發明之揭示] 本發明係提供以下蝕刻液及蝕刻方法。 第1項含有（1)HF及/或其鹽、（2)H2S04及因應 需要進而含有（3)水之l〇w-k膜用之蝕刻液。 -4- 200524040 (2) 第2項如第1項之蝕刻液’其中，H F之鹽係選自氟 化物鹽及二氟化物鹽所成群之至少一種。 第3項如第1項之蝕刻液，其中，HF鹽氟化銨或氫 二氟錢。 第4項如第1項之蝕刻液，其中，含HF或其鹽含 0.5 〜20 mass %、H2SO4 60 〜99.5 mass %、水 〇 〜20 mass % ° 第5項如第1項之蝕刻液，其中，含HF或其鹽含1 〜15 mass 0/〇、H2SO4 60 〜99 mass %、水 0 〜20 mass %。 第6項如第1項之蝕刻液，其中，含HF或其鹽含1 〜10 mass %、H2SO4 85 〜99 mass %、水 0 〜5 mass % 〇 弟7項使如第1項至第6項之触刻液，作用於具有 l〇w-k膜之半導體基板爲特徵之i〇w-k膜蝕刻方法。 第8項如第7項之方法，其中，於半導體基板使如第 1項至第6項之蝕刻液作用，接著進行洗淨，重複上述操 作來蝕刻low-k膜。 第9項如第7項之方法，其中，在半導體基板使如第 1項至第6項之蝕刻液作用，接著使i〇w_k膜之蝕刻殘渣 以使用稀氟酸或緩衝氫氟酸予以洗淨除去者。 [用以實施發明之最佳型態] 本發明之蝕刻液，可由濕蝕刻將晶片表面之low_k膜 除去。 -5- 200524040 (3) 所除去之low-k膜爲，因02等離子作用而受損之物 質’具體的意味著，比介電大於1，小於4程度，理想爲 3以下程度，更理想爲2,8以下，最理想爲2.6以下程度 之絕緣膜。Low-k膜，可列舉如 Black Diamond (商品 名，Upright Mterials 公司製）、Coral (商品名，Novellus 公司製）、LKD series (商品名，JSR公司製）、Aourora (商品名，asm公司製）、HSG Siries (商品名（日本日化成 公司製）、Nanoglass (商品名，Honewell公司製）、IPS (商 品名，曰本觸媒化成公司製）、Z3MS (商品名，Dow Corning公司製）、XLK (商品名，Dow Corning公司製）、 Orion (商品名，Trikon公司製）等。 本發明特別是，可將製膜時晶片斜部或裏面等不需要 之處所附著之l〇w-k膜以濕蝕刻而除去。 有關本發明之蝕刻液適用之含low-k膜晶片，可由蝕 刻除去low-k膜者無特別限制，可使用塗敷、浸漬、噴 霧、噴射等之任意方法。又，斜面部之洗淨可使用專用之 洗淨裝置（例如，SEZ公司製）進行。又，應用 HF-H2S04系之蝕刻液後，因應需要所使用之稀氟酸或緩衝 氫氟酸之應用，同樣可使用塗敷、浸漬、噴霧、噴射等之 任意方法，斜面部之洗淨亦可使用專用之洗淨裝置。 本發明之蝕刻液之適用溫度，爲10〜150°C程度，以 室溫附近爲理想，於該溫度應用本發明之蝕刻液於具有 l〇w-k幞之晶片，可將low-k膜蝕刻。蝕刻液之適用時間 依膜厚而定，一般爲5秒至30分鐘程度。又，應用HF- -6 - 200524040 (4) h2so4系之蝕刻液後，因應需要所使用之稀氟酸或緩衝 氫氟酸之應用，其適用溫度，爲1 0〜1 5 (TC程度，以室溫 附近爲理想，適用時間爲5秒至3 0分鐘程度。 於本發明之蝕刻方法，將本發明之蝕刻液對具有 l〇w-k膜之晶片於上述適用時間之間可連續進行應用，一 旦應用本發明之蝕刻液後，將該蝕刻液洗淨除去，接著再 度重複應用發本明蝕刻液之操作除去l〇w-k膜亦可。重複 蝕刻液之應用與洗淨時，上述之適用時間爲其合計量。 又，使用本發明之蝕刻液進行蝕刻處理後，low-k膜 之蝕刻殘渣使用稀氟酸或緩衝氫氟酸蝕刻除去之2階段步 驟進行蝕刻處理亦可。 緩衝氫氟酸，，可列舉如HF、含HF鹽及水者。 使用本發明蝕刻液後所使用稀氟酸之濃度爲0 · 1〜5 0 質量°/。程度，又，緩衝氫氟酸之濃度爲HF濃度0·1〜20 質量％、HF鹽之濃度爲1〜45質量％者。 緩衝氫氟酸所使用之HF鹽’可列舉如形成HF與鹽 之鹼（特別是含氮鹼）之鹽。該鹼可列舉如氨、羥基胺 類、脂肪族胺類、芳香族胺類、脂肪族或芳香族之第4級 銨鹽，HF鹽爲選自此等鹼所成群之至少一種與HF之 鹽。緩衝氫氟酸所配合之該HF鹽’可使用配合於本發明 蝕刻液之HF鹽相同者。 理想之緩衝氫氟酸，可列舉如HF-NH4 F-H2〇、HF-ch3 nh3 f_h2〇、hf_ch3 ch2 nh3 f_h2o、 HF-(CH3 ) 4 NF-H20 等。 200524040 (5) 本發明之蝕刻方法，以含有硫酸與HF或其鹽之蝕刻 液處理後，以稀氟酸或緩衝氫氟酸處理，進行1 〇 w - k膜之 蝕刻。不以含有硫酸之本發明蝕刻液處理，由於優先引起 l〇w-k膜之剝離，不能使用稀氟酸。又，不以含有硫酸之 本發明蝕刻液處理，以緩衝氫氟酸處理時，low-k膜緩慢 蝕刻蝕刻時間過長不理想。 一方面，含有硫酸之本發明蝕刻液理後，進而使用稀 氟酸或緩衝氫氟酸蝕刻之被蝕刻物，可使用超純水洗淨。 形成HF與鹽之鹼，特別是含氮鹼可列舉如氨、羥基 胺類、脂肪族胺類、芳香族胺類、脂肪族或芳香族之第4 級銨鹽，HF鹽例示如爲選自此等鹼所成群之至少一種與 HF之鹽。 本發明之蝕刻液，或配合緩衝氫氟酸之HF鹽，例示 如氟化物鹽 （HF :鹼 =1 : 1)及重氟化物鹽 （HF :鹼 =2 ·· 1 ) 〇 於本申請書，羥基胺類，列舉如N，N-二甲基羥基 胺、N-乙羥基胺、N，N-二乙羥基胺、N-丙基胺、N-苯羥 基胺等之直鏈或具有分枝之碳數1〜4之烷基或苯基1或 2被取代之羥基胺。 脂肪族胺可列舉如乙胺、丙胺、異丙胺、丁胺、己 胺、辛胺、癸胺、月桂胺、二甲胺、二乙胺、二丙胺、二 異丙胺、二丁胺、三甲胺、三乙胺、三丙胺、三異丙胺、 三丁胺等之直鏈或具有分枝之碳數1〜8之烷基1，2或3 被取代之脂肪族胺，單乙醇胺、乙烯二胺、2-(2-胺基乙 200524040 (6) 胺）乙醇、乙基二乙醇胺、2-乙胺乙醇、二甲胺乙醇、乙 基二乙醇胺、環己胺、二環己胺等。 芳香族胺可列舉如苯胺、N-甲基苯胺、N，N-二甲基苯 胺、苄基胺、N -甲基苄基胺等。 脂肪族或芳香族第4級銨鹽，可列舉如四乙基銨、四 丙基銨、四異丙基銨、四丁基銨、四苯基銨等之脂肪族或 芳香族第4級銨之鹽酸鹽’氫溴酸鹽、硫酸鹽、硝酸鹽等 之礦酸鹽。 由含氮鹼成分與氫氟酸所成之氟化物鹽，可例示如含 氮鹼成分與氫氟酸以1 : 1之莫耳比所結合之化合物，例 如氨與氫氟酸所成之氟化物鹽爲氟化銨，羥基胺類、脂肪 族胺類、芳香族胺類與氫氟酸亦相同，兩者以1 : 1之比 率結合所形成之氟化物鹽[(含鹼成分）HF]。 由脂肪酸或芳香族第4級銨與氫氟酸所成之氟化物鹽， 以[(脂肪酸或芳香族第4級銨）HF]表示。 同樣，由含氮驗成分與氫氟酸所成之氟化物鹽，可例 示如含氮鹼成分與氫氟酸以1 : 2之莫耳比所結合之化合 物，例如氨與氫氟酸所成之氟化物鹽爲二氟化銨，羥基胺 類、脂肪族胺類、芳香族胺類與氫氟酸亦相同，兩者以 1 : 2之比率結合所形成之氟化物鹽[(含鹼成分）2 H F ]。 由脂肪酸或芳香族第4級銨與氫氟酸所成之氟化物鹽， 以[(脂肪酸或芳香族第4級銨）HF]表示。 HF可使用無水截酸’亦可使用約50 mass %氧酸之稀 氟酸。 -9- 200524040 (7) 本發明之蝕刻液，同時使用 HF或其鹽與硫酸。硫酸 以使用98%之濃硫酸（水2%)爲理想，亦可使用工業用 硫酸（90〜98%，其餘爲水），亦可使用發煙硫酸。 本發明之蝕刻液爲含有 （1) HF及 /或其鹽、（2) H2S04及因應需要進而含有（3)水。此3成分合計1〇〇 mass %，其 （1)HF及 /或其鹽之配合量依HF或其鹽之 種類，例如使用HF時，通常爲0.5〜20 mass % :理想爲 1〜15 mass %:更理想爲1〜10 mass %。HF之量過多 時，藥液之蒸氣壓高不合適，HF之量過少時low-k膜之 蝕刻速度緩慢不理想。使用HF鹽（含氮鹼之其他鹽）時 之使用量，可計算如HF之同樣莫耳數。 H2S〇4之使用量，通常爲60〜99.5 mass %程度：理 想爲75〜99 mass %程度：更理想爲85〜99 mass °/〇程 度。H2S04可依HF或其鹽或水之使用量適當的決定。 水之使用量’通常爲〇〜20 mass %程度：理想爲〇〜 1 0 m a s s %程度：更理想爲〇〜5 ni a s s。程度。水之使用 量過多時，l〇w-k膜之蝕刻速度變慢不理想。 水爲任意成分，水之配合量其下限爲0 mass % ’理 想爲0.3 mass %以上，更理想爲〇.5 mass %以上，再理想 爲0.7 m a s s %以上，特別理想爲1 . 〇 m a s s %以上。或 H2S04至少一部份使用濃硫酸（含水率爲2〜10 mass % 程度，HF使用稀氟酸等’亦可調整含水量。水之配合 量，以不產生HF氣體，或S03氣體等程度之量爲理想。 上述3成分之合計量爲1〇〇 mass %’ -10- 200524040 (8) HF及 /或其鹽： H2S04 : 水 =0·5 〜20 mass % : 60 〜99.5 mass %: 0 〜 2 0 mass % ； 理想爲H F及 / 或其 鹽 .Η 2 S 0 4 ·水=1 〜 15 mass % ： 75 〜99 mass % ：0〜 1 0 mass % ;更理想爲HF及 /或其鹽：H2 S Ο4 :水 =1 〜10 mass %: 85 〜99 mass %: 0 〜5 mass % 〇 本發明之蝕刻液，上述3成分以外可進而配合酸或氧 化劑。可配合之酸可列舉如硫酸、鹽酸等之無機酸，三氟 醋酸、甲烷磺酸、甲苯磺酸等之有機酸。可配合之氧化 劑，可列舉如過氧化氫、氯酸、次亞氯酸、過氯酸等。 依本發明，可由充分之蝕刻率蝕刻除去l〇w-k膜。 【實施方式】 以下使用實施例及比較例詳細說明本發明。 實施例1 於濃硫酸 （9 8 m a s s %，其餘爲水）配合1 m a s s %、5 mass %、10 mass %無水氟酸 （HF)製作蝕刻液，於室溫 將具有l〇w-k膜之晶片 （Black DiamondTM(BD))各自浸 漬於各該蝕刻液。蝕刻液之溫度爲23 t。重複晶片浸漬 後，以超純水洗淨乾燥之操作，浸漬時間之合計爲蝕刻時 間。又，殘膜量，爲晶片於鈾刻液浸漬後以超純水洗淨乾 燥後測定。結果如圖1所示。 如圖1所示，隨著無水氧酸之配合量由1 m a s s %至5 m a s s %增大，触刻速度亦增大，5 m a s s % 與1 0 m a s s % -11 - 200524040 Ο) 之蝕刻速度無多大之變化。 又，使2種類無水氟酸之濃度（5 mass %)之蝕刻液作用矽熱氧化膜 （THOH)時 刻，其蝕刻量5分鐘之浸漬時間約爲20A (5 氟酸）及1 6 0 A (1 0 m a s S %無水氟酸），可知蝕 k膜比熱氧化膜高。 實施例2The low-k film is known to use a dry etching removal technique, and the etching solution which is quickly removed by wet etching is not known. Regarding wet etching, as disclosed in Japanese Patent Application Laid-Open No. 2000-164585, Japanese Patent Application Laid-Open No. 2000-164586, and Japanese Patent Application Laid-Open No. 2000-246378, it is disclosed to etch Si O 2 or doped oxide film (BSG, BPSG, PSG, etc.) is not shown for the Llow-k film. The present invention provides an etching solution and an etching method for wet-etching a low_k film sufficiently and practically and rapidly. [Summary of the Invention] [Disclosure of the Invention] The present invention provides the following etching solution and etching method. The first item contains (1) HF and / or a salt thereof, (2) H2S04, and an etching solution for a 10w-k film containing (3) water as needed. -4- 200524040 (2) The etching solution of item 2 as described in item 1, wherein the salt of H F is at least one selected from the group consisting of a fluoride salt and a difluoride salt. Item 3 is the etching solution according to item 1, wherein the HF salt is ammonium fluoride or hydrogen difluoride. The etching solution of item 4 as in item 1, wherein HF or its salt contains 0.5 to 20 mass%, H2SO4 60 to 99.5 mass%, and water 0 to 20 mass% ° The etching solution of item 5 as in item 1, Among them, HF or its salt contains 1 to 15 mass 0 / 〇, H2SO4 60 to 99 mass%, and water 0 to 20 mass%. Item 6 is the etching solution according to item 1, wherein HF or its salt contains 1 to 10 mass%, H2SO4 85 to 99 mass%, and water 0 to 5 mass%. The seventh item is as described in items 1 to 6 The etching solution of the item is an etching method for the iWk film, which is characterized by a semiconductor substrate having a 10Wk film. Item 8 is the method of item 7, wherein the etching solution as described in items 1 to 6 is applied to the semiconductor substrate, followed by cleaning, and the above-mentioned operations are repeated to etch the low-k film. Item 9 is the method of item 7, wherein the etching solution as described in items 1 to 6 is applied to the semiconductor substrate, and the etching residue of the iwwk film is washed with dilute or buffered hydrofluoric acid. Net remover. [The best form for implementing the invention] The etching solution of the present invention can remove the low_k film on the wafer surface by wet etching. -5- 200524040 (3) The low-k film removed is a substance that is damaged by the action of 02 plasma. Specifically, it means that the specific dielectric is greater than 1, and less than 4, and preferably less than 3, and more preferably An insulating film having a thickness of 2,8 or less is preferably 2.6 or less. Examples of the Low-k film include Black Diamond (trade name, manufactured by Upright Materials), Coral (trade name, manufactured by Novellus), LKD series (trade name, manufactured by JSR), Aourora (trade name, manufactured by asm) , HSG Siries (trade name (manufactured by Nippon Kasei Co., Ltd.), Nanoglass (trade name, manufactured by Honewell Co., Ltd.), IPS (trade name, manufactured by Hitachi Chemical Co., Ltd.), Z3MS (trade name, manufactured by Dow Corning), XLK (Trade name, manufactured by Dow Corning), Orion (trade name, manufactured by Trikon), etc. In the present invention, in particular, a 10wk film attached to an unnecessary portion such as a bevel or the inside of a wafer during film formation can be wet-etched. As for the low-k film-containing wafer to which the etching solution of the present invention is applicable, there is no particular limitation on the low-k film that can be removed by etching, and any method such as coating, dipping, spraying, spraying, etc. can be used. Cleaning can be performed using a dedicated cleaning device (for example, manufactured by SEZ). After applying an HF-H2S04-based etching solution, the application can also be used with dilute or buffered hydrofluoric acid if necessary. For any method such as dipping, spraying, spraying, etc., the special cleaning device can be used for the cleaning of the oblique part. The applicable temperature of the etching solution of the present invention is about 10 ~ 150 ° C, ideally around room temperature. At this temperature, the low-k film can be etched by applying the etching solution of the present invention to a wafer having 10wk 幞. The applicable time of the etching solution depends on the film thickness, generally about 5 seconds to 30 minutes. Also, HF- -6-200524040 (4) The application of dilute or buffered hydrofluoric acid after h2so4 series etching solution, the applicable temperature is 10 ~ 15 (TC level, ideal near room temperature) The applicable time is about 5 seconds to 30 minutes. In the etching method of the present invention, the etching solution of the present invention can be continuously applied to a wafer having a 10wk film between the above applicable times. Once the etching of the present invention is applied, After etching, the etching solution is washed and removed, and then the operation of the Fabenming etching solution is repeatedly applied to remove the 10wk film. When the application and cleaning of the etching solution are repeated, the above application time is the total amount. , Using the etching solution of the present invention After the etching treatment, the etching residue of the low-k film may be etched using a two-step step of dilute or buffered hydrofluoric acid etching. The buffered hydrofluoric acid may include HF, HF-containing salts, and water. After using the etching solution of the present invention, the concentration of the dilute hydrofluoric acid used is from 0. 1 to 50 mass%. The concentration of the buffered hydrofluoric acid is HF concentration of 0.1 to 20% by mass, and the concentration of the HF salt is 1 to 45% by mass. Examples of the HF salt 'used for buffered hydrofluoric acid include salts that form a base (particularly a nitrogen-containing base) of HF and a salt. Examples of the base include ammonia, hydroxylamines, aliphatic amines, aromatic amines, aliphatic or aromatic fourth-order ammonium salts, and HF salts are at least one selected from the group consisting of these bases and HF. salt. As the HF salt 'compounded with buffered hydrofluoric acid, the same HF salt compounded in the etching solution of the present invention can be used. The ideal buffered hydrofluoric acid includes HF-NH4 F-H20, HF-ch3 nh3 f_h2o, hf_ch3 ch2 nh3 f_h2o, HF- (CH3) 4 NF-H20, and the like. 200524040 (5) In the etching method of the present invention, after treating with an etching solution containing sulfuric acid and HF or a salt thereof, it is treated with dilute hydrofluoric acid or buffered hydrofluoric acid to perform etching of a 10 w-k film. Without treatment with the etching solution of the present invention containing sulfuric acid, dilute hydrofluoric acid cannot be used because the peeling of the 10w-k film is preferentially caused. In addition, when not treated with the etching solution of the present invention containing sulfuric acid and treated with buffered hydrofluoric acid, the low-k film is slowly etched and the etching time is too long. On the one hand, the etching solution of the present invention containing sulfuric acid can be washed with ultrapure water after being etched with dilute hydrofluoric acid or buffered hydrofluoric acid. Forming bases of HF and salts, in particular nitrogen-containing bases, such as ammonia, hydroxylamines, aliphatic amines, aromatic amines, aliphatic or aromatic fourth-order ammonium salts, HF salts are exemplified by being selected from Salts of at least one of these bases and HF. The etching solution of the present invention or the HF salt mixed with buffered hydrofluoric acid is exemplified by a fluoride salt (HF: alkali = 1: 1) and a bifluoride salt (HF: alkali = 2 ·· 1). Hydroxylamines include linear, or branched, compounds such as N, N-dimethylhydroxylamine, N-ethylhydroxylamine, N, N-diethylhydroxylamine, N-propylamine, and N-phenylhydroxylamine C1-C4 alkyl or phenyl 1 or 2 substituted hydroxylamine. Examples of the aliphatic amine include ethylamine, propylamine, isopropylamine, butylamine, hexylamine, octylamine, decylamine, laurylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, and trimethylamine , Triethylamine, tripropylamine, triisopropylamine, tributylamine, etc. linear or branched alkyl 1,2 or 3 substituted aliphatic amines, monoethanolamine, ethylenediamine , 2- (2-aminoethyl 200524040 (6) amine) ethanol, ethyl diethanolamine, 2-ethylamine ethanol, dimethylamine ethanol, ethyl diethanolamine, cyclohexylamine, dicyclohexylamine, and the like. Examples of the aromatic amine include aniline, N-methylaniline, N, N-dimethylaniline, benzylamine, and N-methylbenzylamine. Aliphatic or aromatic fourth-order ammonium salts include aliphatic or aromatic fourth-order ammonium such as tetraethylammonium, tetrapropylammonium, tetraisopropylammonium, tetrabutylammonium, and tetraphenylammonium. Hydrochloride 'hydrobromide, sulfate, nitrate, etc. Examples of the fluoride salt formed by a nitrogen-containing alkali component and hydrofluoric acid include, for example, a compound in which the nitrogen-containing alkali component and hydrofluoric acid are combined at a molar ratio of 1: 1, such as the fluorine formed by ammonia and hydrofluoric acid. The ammonium salt is ammonium fluoride, and the same applies to hydroxylamines, aliphatic amines, aromatic amines, and hydrofluoric acid. The fluoride salt formed by combining the two at a ratio of 1: 1 [(containing alkali component) HF] . A fluoride salt formed from a fatty acid or an aromatic fourth-order ammonium and hydrofluoric acid is represented by [(fatty acid or aromatic fourth-order ammonium) HF]. Similarly, a fluoride salt formed by a nitrogen-containing test component and hydrofluoric acid may be exemplified by a compound in which a nitrogen-containing alkali component and hydrofluoric acid are combined at a molar ratio of 1: 2, such as those formed by ammonia and hydrofluoric acid. The fluoride salt is ammonium difluoride, and the same is true for hydroxylamines, aliphatic amines, aromatic amines, and hydrofluoric acid. The fluoride salt formed by combining the two at a ratio of 1: 2 [(containing alkali components ) 2 HF]. A fluoride salt formed from a fatty acid or an aromatic fourth-order ammonium and hydrofluoric acid is represented by [(fatty acid or aromatic fourth-order ammonium) HF]. As the HF, anhydrous acid can be used 'or a dilute fluoric acid of about 50 mass% of oxyacid. -9- 200524040 (7) The etching solution of the present invention uses HF or a salt thereof together with sulfuric acid. Sulfuric acid It is ideal to use 98% concentrated sulfuric acid (2% water). Industrial sulfuric acid (90 ~ 98%, the rest is water) can also be used. Fuming sulfuric acid can also be used. The etching solution of the present invention contains (1) HF and / or a salt thereof, (2) H2S04, and further contains (3) water as necessary. These 3 ingredients total 100%. The amount of (1) HF and / or its salt depends on the type of HF or its salt. For example, when using HF, it is usually 0.5 to 20 mass%: ideally 1 to 15 mass %: More preferably, it is 1 to 10 mass%. When the amount of HF is too large, the vapor pressure of the chemical solution is too high, and when the amount of HF is too small, the etching rate of the low-k film is slow and unsatisfactory. The amount of HF salt (other salts of nitrogen-containing base) can be used to calculate the same mole number as HF. The amount of H2S〇4 used is usually 60 to 99.5 mass%: ideally 75 to 99 mass%: more preferably 85 to 99 mass ° / 〇 degree. H2S04 can be appropriately determined according to the amount of HF or its salt or water. The amount of water used is usually about 0 to 20 mass%: ideally 0 to 10 m a s s%: more preferably 0 to 5 ni a s s. degree. When the amount of water is too much, the etching rate of 10w-k film becomes slow, which is not ideal. Water is an optional component, and the lower limit of the blending amount of water is 0 mass% or more, preferably 0.3 mass% or more, more preferably 0.5 mass% or more, still more preferably 0.7 mass% or more, and particularly preferably 1.0 mass% or more. . Or at least part of H2S04 uses concentrated sulfuric acid (water content is about 2 ~ 10 mass%, HF uses dilute hydrofluoric acid, etc.). The water content can also be adjusted. The amount of water is mixed so as not to produce HF gas, or S03 gas, etc. The total amount of the above 3 components is 100mass% '-10- 200524040 (8) HF and / or its salt: H2S04: water = 0.5 to 20 mass%: 60 to 99.5 mass%: 0 ~ 2 0 mass%; ideally HF and / or its salt. 2 S 0 4 · water = 1 to 15 mass%: 75 to 99 mass%: 0 to 10 mass%; more preferably HF and / or Salt: H2 S 〇4: Water = 1 to 10 mass%: 85 to 99 mass%: 0 to 5 mass% 〇In the etching solution of the present invention, an acid or an oxidizing agent may be added in addition to the above three components. Examples of acids that can be added include: Inorganic acids such as sulfuric acid and hydrochloric acid, organic acids such as trifluoroacetic acid, methanesulfonic acid, toluenesulfonic acid, etc. The oxidizing agents that can be used include hydrogen peroxide, chloric acid, hypochlorous acid, and perchloric acid. In the present invention, a 10wk film can be removed by etching at a sufficient etch rate. [Embodiments] Hereinafter, the present invention will be described in detail using examples and comparative examples. Example 1 An etching solution was prepared by mixing concentrated sulfuric acid (98 mass%, the rest being water) with 1 mass%, 5 mass%, and 10 mass% anhydrous hydrofluoric acid (HF), and a wafer having a 10wk film ( Black DiamondTM (BD)) were immersed in each of these etching solutions. The temperature of the etching solution was 23 t. After the wafer immersion was repeated, the operation of washing and drying with ultrapure water was repeated. The total immersion time was the etching time. Also, the amount of residual film It is measured after the wafer is immersed in uranium etch solution with ultrapure water and dried. The results are shown in Figure 1. As shown in Figure 1, the amount of anhydrous oxygen acid increases from 1 mass% to 5 mass%. , The etching speed also increased, 5 mass% and 10 mass% -11-200524040 〇) the etching rate does not change much. In addition, when a silicon thermal oxide film (THOH) is applied to an etching solution having a concentration of 5 mass% of anhydrous hydrofluoric acid (5 mass%), the immersion time of an etching amount of 5 minutes is about 20 A (5 hydrofluoric acid) and 16 0 A ( 10 mas S% anhydrous hydrofluoric acid), it can be seen that the corrosion k film is higher than the thermal oxidation film. Example 2
將 HF (5 mass %)、水（1.9 mass %、6.8 m a s s %、2 0 m a s s %)及濃硫酸（餘）製作鈾 施例1同樣測量l〇w-k膜 （Black DiamondTM 刻量。結果如圖2所示。 實施例3 於濃硫酸 （98 mass %，其餘爲水）配 (HF) 5 mass %製作蝕刻液，除溫度爲23°C、 以外，與實施例1同樣測量low-k膜（Black (BD))之鈾刻量。結果如圖3所示。 竇施例4 於濃硫酸 （9 8 m a s s %，其餘爲水）配-(HF) 5 mass %，製作蝕刻液，於 23 °C將 (Black DiamondTM (BD)) 之晶片浸漬 1分鐘 洗淨後，於23 t之2.5 mass % HF浸漬指定時 % ' 10 mass THOX被蝕 m a s s %無水 刻速度low- mas s %、10 刻液，與實 (BD))之蝕 合無水氟酸 5(TC 及 4〇C Diamond™ 含無水氟酸 low-k 膜 ，以超純水 間後進行超 -12- 200524040 (10) 純水洗淨，測定殘膜量。結果如表4所示。 又，圖中所示之蝕刻時間〇秒爲，濃硫酸 （98 mass % ’其餘爲3)配合無水氟酸 （HF) 5 mass %製作蝕刻 液，於 23 °C 以刻蝕刻液 low-k 膜（Black DiamondTM (BD))之晶片浸漬〗分鐘，以超純水洗淨後測定之殘膜 量。 又，2.5 mass % HF 使用 6 mass % HF - 30 mass °/〇 N Η 4 F - 6 4 % m a s s % Η 2 Ο之緩衝氫氟酸取代亦可將蝕刻殘 渣迅速的除去。 比較例1 於鹽酸 （36 mass %.，其餘爲水）配合無冰氟酸 （HF) 5 mass %製作蝕刻液，與實施例1同樣測量low-k膜 (Black DiamondTM (BD))之蝕刻量。結果如表1所示。 蝕刻時間（分） 1 2 3 蝕刻量（A) 32 77 膜剝離 如表1所示，由HC1與HF與水所成之蝕刻液，由 於進行必要之鈾刻量前即引起l〇w-k膜之剝離，無法進行 触刻。 比較例2 -13- 200524040 (11) 2 〇 (餘量） 1 〇 w - k 膜 所示。 以 HF (6 mass %) -NH4F (30 mass 〜 之配合製作蝕刻液，與實施例1同樣測量 (Black DiamondTM (BD))之蝕刻量。結果如袠 袠2 間（分） 1 5 10 15 20 30 量（a) 19 5 8 172 480 825 1473 如袠2所示，確認HF -NH4F - H20 之蝕 度慢。 液蝕刻速 【圖式簡單說明】 _ 1所示爲實施例1之結果。 圖2所示爲實施例2之結果。 圖3所示爲實施例3之結果。 _ 4所示爲實施例4之結果。HF (5 mass%), water (1.9 mass%, 6.8 mass%, 20 mass%) and concentrated sulfuric acid (residual) were used to make uranium. Example 1 also measured the 10wk film (Black DiamondTM engraved amount. The results are shown in Figure 2 Example 3 An etching solution was prepared by mixing (HF) 5 mass% with concentrated sulfuric acid (98 mass%, the rest was water), except that the temperature was 23 ° C, and a low-k film (Black (BD)). The results are shown in Figure 3. Sinus Example 4 Mix concentrated sulfuric acid (98 mass%, the rest is water) with-(HF) 5 mass% to make an etching solution at 23 ° C. After immersing the (Black DiamondTM (BD)) wafer for 1 minute and washing it, the 2.5 mass% HF immersion at 23 t is specified at% '10 mass THOX corroded mass% water-free etch rate low- mas s%, 10 etch solution, Anhydrous fluoric acid 5 (TC and 40C Diamond ™ with anhydrous fluoric acid low-k film combined with BD) is washed with ultra-pure water and then super-12- 200524040 (10) washed with pure water, The amount of residual film was measured. The results are shown in Table 4. The etching time shown in the figure is 0 seconds. Concentrated sulfuric acid (98 mass% 'the rest is 3) was combined with anhydrous fluoric acid (HF) 5 mass% to make an etching solution. 23 ° C Dipping with a low-k film (Black DiamondTM (BD)) in an etching solution for one minute, and washing with ultrapure water to measure the residual film amount. Also, 2.5 mass% HF uses 6 mass% HF-30 mass ° / 〇N 取代 4 F-6 4% mass% Η 2 Ο buffered hydrofluoric acid substitution can also quickly remove the etching residue. Comparative Example 1 in hydrochloric acid (36 mass%., the rest is water) combined with ice-free Fluoric acid (HF) 5 mass% was used to make an etching solution, and the etching amount of the low-k film (Black DiamondTM (BD)) was measured in the same manner as in Example 1. The results are shown in Table 1. Etching time (minutes) 1 2 3 Etching amount (A) 32 77 Film peeling As shown in Table 1, the etching solution made of HC1, HF, and water caused peeling of the 10wk film before the necessary amount of uranium engraving was performed, so it was impossible to touch the film. Comparative Example 2 -13- 200524040 (11) 2 〇 (balance) 1 〇w-k film. Etching solution was made with HF (6 mass%) -NH4F (30 mass ~), measured in the same manner as in Example 1 (Black DiamondTM (BD)). The results are shown in 袠 间 2 rooms (minutes) 1 5 10 15 20 30 Amount (a) 19 5 8 172 480 825 1473 As shown in 袠 2, it is confirmed that the corrosion of HF -NH4F-H20 is slow. Liquid Etching Speed [Schematic description] _ 1 shows the result of Example 1. Figure 2 shows the results of Example 2. Figure 3 shows the results of Example 3. _4 shows the results of Example 4.