經濟部中央標準局貝工消费合作社印裝 j) e I 5 7 61 w 1' d ο c / Λ r d c η n e / 0 0 5 八 了 ___40518t_ 五、發明説明（/ ) ~~ 本發明係有關於一種二氧化矽（〇xide)的乾蝕刻（和 etch)法，且特別是有關於一種經氮（No處理（treated)所形成 之二氧化矽的乾蝕刻法。 在丰導體丨木k微米（sub-quarter micron)的二氧化砂蝕 刻技術中，通常採用氟化碳（CxFy)爲氣體，在反應室 (chamber)中結合矽塊(sUiC0n r〇〇f),進行高濃度電漿（出§11 Density Plasma » HDP)乾倉虫刻。例如，AppHe(j Material 出產的HDP 53〇0蝕刻機在反應室中上端置放矽塊，其目 的是用來吸收反應室中的氣原子（fluorine)，如此可提闻一 氧化矽對下層（underlayer)的蝕刻選擇性（etching selectivity)。 習知二氧化矽蝕刻法，其採用的氣體一爲單獨六氟化 二碳(C2F6)氣體；另一爲AMAT所提出C2F6/C4F8/Ar配方 所組成的氣體’或He/C2F6/CHF3配方所組成的氣體等實驗 性組合。例如，後者配方的流量率（flow rate)爲He約7& 400sccm，30-50sccm，CHF3 約 5-15sccm。 請參照第1圖與第2圖，其分別繪示習知採用或 He/C2F6/CHF3，以及C2F6/C4F8/Ar三種鈾刻氣體配方蝕刻 二氧化矽之掃描式電子顯微鏡（Scanning Elect—Printed by the Shellfish Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs j) e I 5 7 61 w 1 'd ο c / Λ rdc η ne / 0 0 5 ___40518t_ V. Description of the invention (/) ~~ The present invention has A dry etching (and etch) method of silicon dioxide (OXIDE), and in particular, a dry etching method of silicon dioxide formed by nitrogen (No treatment). (Sub-quarter micron) sand dioxide etching technology, usually using carbon fluoride (CxFy) as a gas, in the reaction chamber (chamber) combined with silicon blocks (sUiC0n r〇〇f) §11 Density Plasma »HDP) dry worm. For example, the HDP 5300 etching machine produced by AppHe (j Material) puts a silicon block on the upper end of the reaction chamber. The purpose is to absorb the gas atoms (fluorine) in the reaction chamber. ), So that the silicon oxide's etching selectivity of the underlayer (etching selectivity) can be improved. Conventional silicon dioxide etching method, the gas used is a single carbon hexafluoride (C2F6) gas; the other A gas composed of C2F6 / C4F8 / Ar formula proposed by AMAT 'or He / C2F6 / CHF3 formula An experimental combination of the formed gas and the like. For example, the flow rate of the latter formula is about 7 & 400sccm, 30-50sccm, and CHF3 about 5-15sccm. Please refer to Fig. 1 and Fig. 2, which are drawn separately Scanning electron microscope (Scanning Elect—etching silicon dioxide using three He or C2F6 / CHF3 and C2F6 / C4F8 / Ar formulas)
Microscope ; SEM)圖。C2F6 或 He/C2F6/CHF3 蝕刻會有雙 iLIfKetch stop)的現象，導致後續製程電性連接發生問 題，例如第1圖所繪示爲其蝕刻典型的結果。C2F6/C4F“Ai· 蝕刻可以戀韋蝕刻終止I生，但效果不透好，例如第2圖 所繪示。 n n n ^^1 i^l i> 1^1 In^n· an -- - (請先閱讀背面之注意事項存填寫本荑) 本紙張尺度適用中國國家標準（.CNS ) A4規格（21.0><297公釐） f; H c I 5 7 61 w Γ. d 〇 c / A r d e η n c / 0 0 5 ___i〇5l8lj[ 五、發明説明（ > ) " 因此’本發明的主要目的就是在提供一種二氧化砂的 蝕刻法’以一新的配方作爲蝕刻氣體，防止蝕刻終止發生， 確保後續製程電性連接良好。 根據本發明之主要目的，提出—種二氧化砂的乾軸刻 法，係採用反應室中置放有矽塊之一高濃度電漿蝕刻機爲 乾蝕刻機，並以流量率分別爲六氟化二碳約30_60sccm， 氬約40-200Sccm’氧約3-10sccm哎組成氣體爲反應氣體， 進行該二氧化矽乾蝕刻。 爲讓本發明之上述和其他目的、特徵、和優點能更明 顯易懂，下文特舉一較佳實施例，並配合所附圖式，作詳 細說明如下： 圖式之簡單說明： 第1圖是習知採Cj6或He/C2F6/CHF3爲蝕刻氣體配方 蝕刻二氧化矽之掃描式電子顯微鏡圖； 第2圖是習知採C2F6/C4F8/Ar爲蝕刻氣體配方蝕刻二 氧化矽之掃描式電子顯微鏡圖； 第3A圖是不經N2處理的薄膜蝕刻時光學放射光譜 圖；以及 經濟部中央標準局貝工消费合作社印繁 1-. -- ϋ 1 I - - n I- - . 1- - i - I - 丁 、i-9 f {諳先閑讀背面之注意事項再填寫本頁} 第3B圖爲經過N2處理的薄膜蝕刻時光學放射光譜 圖。 較佳實施仿1 請參照第3A圖與第3B圖。第3A圖爲不經N2處理的 薄膜（film)触刻時光學放射光譜（Optical Emission 4 本紙張尺度適用中國國家標準（CNS ) A4规格（210X 297公釐） 經濟部中央標隼局員工消費合作社印製 T05181 I7 五、發明説明（；）Microscope; SEM). C2F6 or He / C2F6 / CHF3 etching will have a double iLIfKetch stop) phenomenon, which will cause problems in subsequent electrical connections. For example, Figure 1 shows the typical results of its etching. C2F6 / C4F "Ai · Etching can be used to stop etching, but the effect is not good, as shown in Figure 2. nnn ^^ 1 i ^ l i > 1 ^ 1 In ^ n · an--( Please read the notes on the back and fill in this first.) This paper size applies Chinese National Standard (.CNS) A4 specification (21.0 > < 297 mm) f; H c I 5 7 61 w Γ. D 〇c / A rde η nc / 0 0 5 ___ i〇5l8lj [V. Description of the invention (>) " Therefore, 'the main purpose of the present invention is to provide an etching method of sand dioxide' with a new formula as an etching gas to prevent The termination of etching occurs to ensure good electrical connection in subsequent processes. According to the main purpose of the present invention, a dry-axis engraving method of sand dioxide is proposed, which uses a high-concentration plasma etching machine in which a silicon block is placed in the reaction chamber. The dry etching machine performs the silicon dioxide dry etching at a flow rate of about 30-60 sccm of dicarbon hexafluoride, about 40-200 sccm of argon, and about 3-10 sccm of oxygen, respectively. To make the silicon dioxide dry etching. And other purposes, features, and advantages can be more clearly understood, a preferred embodiment is given below. In conjunction with the attached drawings, the detailed description is as follows: Brief description of the drawings: Figure 1 is a scanning electron microscope image of the conventional etching of silicon dioxide with Cj6 or He / C2F6 / CHF3 as the etching gas formula; The figure is a scanning electron microscope image of conventionally etched silicon dioxide using C2F6 / C4F8 / Ar as the etching gas formula; Figure 3A is an optical emission spectrum of a thin film without N2 treatment; and the sheller of the Central Standards Bureau of the Ministry of Economy Consumption Cooperatives India Fan 1-.-Ϋ 1 I--n I--. 1--i-I-Ding, i-9 f {谙 Please read the precautions on the back before filling out this page} Figure 3B is Optical emission spectrum of N2 treated thin film during etching. Best Practice Imitation 1 Please refer to Figures 3A and 3B. Figure 3A shows the optical emission spectrum (Optical Emission 4) of the film without N2 treatment when touched. This paper size applies to Chinese National Standard (CNS) A4 (210X 297 mm) Printed by the Consumer Cooperatives of the Central Standardization Bureau of the Ministry of Economic Affairs T05181 I7 V. Description of the invention (;)
Spectroscopy ; OES)圖，例如軸刻電漿加強型四乙基砂酸 鹽（？1&51113£11!1&115€(1-丁£08;?£-丁£08)薄膜。第38圖爲經 過N2處理的薄膜蝕刻時光學放射光譜圖，例如蝕刻1^2處 理的自對準化學氣象沈積（Self-A丨igned Chemical Vapor Deposition ; SA-CVD)二氧化矽薄膜。本發明實驗發現， 第3A圖沒有氮化碳（CN)峰値(peak)，並且不會發生蝕刻終 止；第3B圖會有CN峰値，並且鸯生蝕刻終止。因此，判 斷CN的形成與蝕刻終止有很大的關聯。 高濃度電漿系統對反應室的環境是非常敏感的，在反 應室中碳（Carbon ; C)的含量對蝕刻能力有著極大的影 響，維持系統中高碳含量可以獲得高的《二氧化矽/光阻》 (oxide/PR)蝕刻選擇性（selectivity)。然而，當系統碳含量 高時，並蝕刻至N2處理的薄膜（例如，BP-TEOS，PE Oxide/SA-CVD)通常會發生蝕刻終止。因此，本發明以爲 蝕刻終止是因蝕刻時C與>12的附加反應形成CN所導致 的。當蝕刻時CN形成後，會沈積在洞底形成CN薄膜，阻 止蝕刻繼續進行，造成蝕刻終止。蝕刻反應模型如下：Spectroscopy; OES) diagrams, such as axon-etched plasma-enhanced tetraethyl oxalate (? 1 & 51113 £ 11! 1 & 115 € (1-but £ 08;? £ -but £ 08) film. Figure 38 The optical emission spectrum of the N2 treated thin film is etched, for example, a self-aligned chemical vapor deposition (SA-CVD) silicon dioxide thin film treated with 1 ^ 2 is etched. According to the experimental findings of the present invention, Figure 3A has no carbon nitride (CN) peak and no etch termination; Figure 3B has CN peak and etch termination. Therefore, it is judged that the formation of CN and the etch termination are very large. The high-concentration plasma system is very sensitive to the environment of the reaction chamber, and the carbon (Carbon; C) content in the reaction chamber has a great impact on the etching ability. Maintaining a high carbon content in the system can obtain a high "dioxide Silicon / photoresist (oxide / PR) etch selectivity. However, when the system carbon content is high and etched to N2-treated films (eg, BP-TEOS, PE Oxide / SA-CVD), it usually occurs Etching is terminated. Therefore, the present invention considers that the etching is terminated because C and > 12 caused by the additional reaction of CN. When CN is formed during etching, it will be deposited on the bottom of the hole to form a CN film, which prevents the etching from continuing and causes the etching to stop. The etching reaction model is as follows:
Cx--Fy+Si02—^s_^SiF4+CO+COF2 Cx--Fy+N-sp，，eous )CN+NF3 因此’本發明假設二氧化矽蝕刻終止是CN形成所導 致的。以此假設理論爲出發點，本發明以C2F6+Ar、 CA+Hei CHf3與C2F6+〇2等三種配方進行蝕刻實驗。經實 H HI ^^1 n —-I In ^^1 In αψ an (請先閲讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國^$ ( CNS ) A4規格（210X 297公釐) ~ 經濟部中央橾隼局貝工消费合作社印裝Cx--Fy + Si02— ^ s_ ^ SiF4 + CO + COF2 Cx--Fy + N-sp ,, eous) CN + NF3 Therefore, the present invention assumes that the termination of silicon dioxide etching is caused by CN formation. Taking this hypothetical theory as a starting point, the present invention performs etching experiments with three formulations, such as C2F6 + Ar, CA + Hei CHf3, and C2F6 + 02. H HI ^^ 1 n —-I In ^^ 1 In αψan (Please read the notes on the back before filling this page) This paper size is applicable to China ^ $ (CNS) A4 size (210X 297 mm) ~ Printed by Shellfish Consumer Cooperative, Central Bureau of the Ministry of Economic Affairs
Filcl576twfdoc/Ardennc/005 ____405181 B7___ 五、發明説明（令） 驗發現： (1) C2F6+〇2 :可有效防止蝕刻終止，但光阻損失量增 加： (2) C2F6+He+CHF3 :無法有效防止蝕刻終止； (3) C2F6+Ar :可防止蝕刻終止，但效果不如c2F6+〇2 好，其優點是光阻損失較少。 本發明較佳實施例依上述假载實驗結果，而選取最佳 的配方爲CJJAr/O2，不但可以避免蝕刻終止，並且可維 持較高的《二氧化矽/光阻》蝕刻選擇性。例如，採用高濃 度電漿触刻機爲乾蝕刻機，並在反應室中置放砂塊，以 C^FJAr/O2爲氣體，進行二氧化ξ夕乾触刻。其中， C2F6/Ar/02氣體流量率爲（:仏約30-60sccm，Ar約40-200sccm，〇2 約 3-10sccm 〇 由上述本發明較佳實施例可知’應用本發明較佳實施 例所提出的二氧化砂乾軸刻法不但可以解決触刻終止的 問題’更具有高《二氧化矽/光阻》触刻選擇性與高《二氧 化矽/下層》蝕刻選擇性之優點。 雖然本發明已以較佳實施例揭露如上，然其並非用以 限定本發明，任何熟習此技藝者’在不脫離本發明之精神 和範圍內，當可作各種之更動與潤飾，因此本;發明之保護 範圍當視後附之申請專利範圍所界定者爲$。 & 6 張尺度適用中國國家石隼（CNS ) A4規格（210X297公釐） n^i ^nf It l ί ^11^1 n^— (請先M讀背面之注意事項再填寫本頁)Filcl576twfdoc / Ardennc / 005 ____405181 B7___ 5. Description of the Invention (Order) It was found that: (1) C2F6 + 〇2: It can effectively prevent the termination of etching, but the photoresistance loss increases: (2) C2F6 + He + CHF3: It cannot effectively prevent etching Termination; (3) C2F6 + Ar: It can prevent the termination of etching, but the effect is not as good as c2F6 + 〇2, which has the advantage of less photoresistance loss. The preferred embodiment of the present invention selects the best formula as CJJAr / O2 based on the results of the above-mentioned dummy load test, which not only avoids the termination of etching, but also maintains a higher "silicon dioxide / photoresist" etching selectivity. For example, using a high-concentration plasma touch engraving machine as a dry etcher, and placing a sand block in the reaction chamber, and using C ^ FJAr / O2 as a gas, dry contact etch for oxidizing xi. Among them, the C2F6 / Ar / 02 gas flow rate is (: about 30-60 sccm, Ar about 40-200 sccm, 〇2 about 3-10 sccm.) From the above-mentioned preferred embodiment of the present invention, it can be known that 'the application of the preferred embodiment of the present invention The proposed dry shaft engraving method of sand dioxide can not only solve the problem of contact termination, but also has the advantages of high "silicon dioxide / photoresist" touch selectivity and high "silicon dioxide / underlayer" etching selectivity. The invention has been disclosed in the preferred embodiment as above, but it is not intended to limit the invention. Anyone skilled in the art can make various modifications and retouches without departing from the spirit and scope of the invention. The scope of protection shall be defined as the scope of the patent application attached as follows: & 6 scales are applicable to China National Stone Cricket (CNS) A4 specification (210X297 mm) n ^ i ^ nf It l ^ 11 ^ 1 n ^ — (Please read the notes on the back before filling in this page)