經淨.部中央標準局員工消货合作牡印^. A v B? _ 五、發明説叫ί ' 發明頜域= 本發明與一種半導體製程有關，特別是一種接觸洞 (contact hole)之蝕刻方法俾使所蝕刻之深度超越蝕刻機 台之限制。 發明背景= 積體電路之流程非常複雜，基本上大致可分爲晶片 之製造、積體電路之製作與積體電路之構裝（package)， 半導體工業因爲技術的提昇而朝向將元件之尺寸縮小遵 進，將各種電子元件及線路縮小並製作在大小僅及2平 方公分或更小之面積上。在積體電路體製程目前趨向於多 重內連線之製作。爲了達到不同膜層間之電性接觸，接觸 洞之製作是必要之製作步驟。當半導體元件不斷地縮小 時，接觸洞之大小亦減小。 一般所稱之C3接觸洞適用在由中間介電層（interlayer dielectric ; ILD) 開始 ，控開通至複 晶矽層-4、 複晶 矽層-2、複晶矽層-1與底材做連接金屬導電線路之通路。 —般於DRAM之C3蝕刻時 > 均應用高密度電漿（high density plasma ; HDP)蝕刻來達到接觸洞之蝕刻。利用 上述之製程做接觸洞之蝕刻最大深度約爲2.7微米，基於 此項因子之限制，皇冠形電容記憶胞結構於製作上便面臨 了一些問題|例如介電層之厚度與電容記憶胞之高度變直 ^紙張尺度迪川巾國囤家標準) Λ4現格（210X 2971、釐） {請先邓讀吒*之a意事項再填μ*本頁)Jing Jing. The Central Bureau of Standards of the People ’s Republic of China eliminates the goods and cooperates with the seal ^. A v B? _ V. The invention is called ί 'Invention jaw area = This invention is related to a semiconductor process, especially a contact hole etch The method makes the depth of the etching beyond the limitation of the etching machine. Background of the Invention = The flow of integrated circuits is very complicated. It can be roughly divided into the manufacture of chips, the production of integrated circuits, and the packaging of integrated circuits. The semiconductor industry is moving towards reducing the size of components due to technological advancements. Zunjin has reduced and produced various electronic components and circuits in an area of only 2 square centimeters or less. At present, the integrated circuit system process tends to produce multiple interconnects. In order to achieve electrical contact between different film layers, the fabrication of contact holes is a necessary fabrication step. As the semiconductor device shrinks continuously, the size of the contact hole also decreases. The so-called C3 contact hole is generally suitable for connecting from the interlayer dielectric (ILD) to the polycrystalline silicon layer-4, the polycrystalline silicon layer-2, the polycrystalline silicon layer-1 and the substrate. Path of metal conductive line. —Generally when C3 etching of DRAM > High density plasma (HDP) etching is used to achieve contact hole etching. The maximum depth of the contact hole etch using the above process is about 2.7 microns. Due to the limitation of this factor, the crown-shaped capacitor memory cell structure faces some problems in the production | such as the thickness of the dielectric layer and the height of the capacitor memory cell. Straighten ^ Paper scale Dichuan towel national standard) Λ4 is now (210X 2971, centimeters) {Please read the meaning of a in Deng * and fill in μ * this page)
T 装 -1° 4 D ό ϋ ^ Λ" _______ΙΓ -五、绛明説明（) 接受其影響。所以提昇接觸窗於介電層中之被蝕刻深度可 以增加半導體製程之容易度和可靠度。 發明目的及槪沭： 本發明之主要目的在提供一種絕緣氧化矽層之蝕刻 方法。T 装 -1 ° 4 D ό ϋ ^ Λ " _______ ΙΓ-V. Ming Ming explained () Accept the impact. Therefore, increasing the etching depth of the contact window in the dielectric layer can increase the ease and reliability of the semiconductor process. OBJECTS AND PROBLEMS OF THE INVENTION: The main object of the present invention is to provide an etching method for an insulating silicon oxide layer.
A 本發明之另一目的爲提供一種蝕刻方法以提供一較 深之接觸洞（contact hole)。 本發明之再一目的爲提供一種利用含氟氣體以及提 供一磁場以蝕刻接觸洞之方法。 經Μ部中央標卑局Kvi消贽合竹社印來 一相對於絕緣層有較高蝕刻選擇性之膜層形成於絕 綠層之上作爲形成接觸洞之硬式罩幕（hard mask)。此硬 式罩幕可以選用非晶形矽、氫摻雜之非晶形矽或是複晶 矽。接著，一光阻形成於硬式罩幕之上用以定義接觸洞之 圖案。隨後，以光阻做爲蝕刻之罩幕將硬式罩幕蝕刻俾以 將接觸洞圖案轉移至硬式罩幕中。一具有惰性氣體之載 氣、含氟之蝕刻劑以及氬氣之混合氣體通入反應室中。惰 性氣體則使用氦或氬 > 提供一電漿與提供一磁場用以蝕刻 絕緣層。爲了提昇蝕刻之能力，一含Ar +離子物理性轟擊 亦同時用來撞擊氧化物，蝕刻直到曝露底材爲止》最後一 步驟爲去除硬式罩幕。 圖式簡單說明= 本紙张尺度適用中&囤家標導(C'NS ) Λ4現格（210X297公釐） 425632 B7 JL、發明説明（} 第一圖爲本發明之流程圖。 第二圖爲本發明之形成硬式罩幕於絕緣層上之截面圖。 第三圖爲本發明之蝕刻後之截面圖。 發明詳細說明： 本發明主要提供一種深接觸洞之蝕刻方法必以超越 目前高密度電漿蝕刻機台之限制。本發明包含利用含氟之 蝕刻氣體以及以磁場加速之高活性、高動量之反應性離子 用以蝕刻至少一層之介電層。 第一圖爲本發明之流程圖。首先，於步驟1〇〇中一 硬式罩幕形成於介電層之上。此硬式罩幕包含一開口用以 形成一接觸洞。第二圖爲對應於第一圖步驟彳〇〇之截面 示意圖。由圖中可知半導體底材2包含至少一層介電層 4。其他之絕緣區域與元件則未圖示第二圖中。以習知技 術而言，上述之介電層通常作爲絕緣用途1以一實施例而 言可以爲氧化物所組成，例如氧化矽、TEOS、SOG、BPSG 或 PSG。 隨後，一相對於絕緣層4有較高蝕刻選擇性之膜層 形成於絕緣層4之上作爲形成接觸洞之硬式罩幕6。此硬 式罩幕6可以選用非晶形矽（a-Si)、氫摻雜之非晶形矽氫 (a-ShH)，或是複晶矽（poly-Si)。以較佳實施例而言，爲 本紙乐尺度適州中國囤家標丰（CNS ) Λ4規格（21 0X 297公麈） ί"·先閱清外而之注意事項再瑣寫本頁)A Another object of the present invention is to provide an etching method to provide a deep contact hole. Another object of the present invention is to provide a method for etching a contact hole by using a fluorine-containing gas and providing a magnetic field. Printed by the Central Bureau of M, Kvi, Hezhu, a film with a higher etch selectivity than the insulating layer is formed on the green layer as a hard mask for forming contact holes. The hard mask can be made of amorphous silicon, hydrogen-doped amorphous silicon, or polycrystalline silicon. Then, a photoresist is formed on the hard mask to define the pattern of the contact hole. Subsequently, the hard mask is etched with a photoresist as an etching mask to transfer the contact hole pattern into the hard mask. A mixed gas of a carrier gas having an inert gas, an etchant containing fluorine, and argon gas is passed into the reaction chamber. The inert gas uses helium or argon > provides a plasma and a magnetic field to etch the insulating layer. In order to improve the ability of etching, a physical bombardment containing Ar + ions is also used to strike the oxide, and the etching is continued until the substrate is exposed. The final step is to remove the hard mask. Brief description of the drawing = This paper's standard is suitable for & store house guide (C'NS) Λ4 present (210X297 mm) 425632 B7 JL, description of the invention () The first picture is the flowchart of the present invention. The second picture This is a cross-sectional view of the hard mask formed on the insulating layer of the present invention. The third figure is a cross-sectional view of the present invention after etching. Detailed description of the invention: The present invention mainly provides a deep contact hole etching method which must surpass the current high density Limitation of plasma etching machine. The present invention includes the use of fluorine-containing etching gas and highly active, high-reaction reactive ions accelerated by a magnetic field to etch at least one dielectric layer. The first figure is a flowchart of the present invention. First, a hard mask is formed on the dielectric layer in step 100. The hard mask includes an opening for forming a contact hole. The second figure is a cross section corresponding to step OO in the first figure. Schematic. It can be seen from the figure that the semiconductor substrate 2 includes at least one dielectric layer 4. The other insulating regions and components are not shown in the second figure. In terms of conventional technology, the above-mentioned dielectric layer is usually used as an insulation 1 Yi Shi For example, it can be composed of an oxide, such as silicon oxide, TEOS, SOG, BPSG, or PSG. Subsequently, a film layer having a higher etching selectivity than the insulating layer 4 is formed on the insulating layer 4 as a contact hole. Hard mask 6. This hard mask 6 can be selected from amorphous silicon (a-Si), hydrogen-doped amorphous silicon hydrogen (a-ShH), or polycrystalline silicon (poly-Si). For the example, this paper is a Chinese version of the standard Chinese storehouse in China (CNS) Λ4 specification (21 0X 297 gong) ί " Read the precautions before clearing this page, and then write this page trivially)
^潢部中夾標枣局貞工消贽合作社印# 4 256-^P v ίΓ 五、發明説明（) ί吏用a-Si或a-Si:H作爲硬式罩幕6因其之電漿沈積薄 膜之製程溫度約爲30CTC。氧化矽對a-Si或a-Si:H之蝕 刻比約爲1 〇: 1至2 0 :1。 接著，一光阻8形成於硬式罩幕6之上用以定義接 觸洞之圖案。隨後，以光阻8做爲蝕刻之罩幕將硬式罩 幕6蝕刻俾以將接觸洞圖案轉移至硬式罩幕6中。光阻 可以選擇性地去除或留下。 參閱第一圖，步驟110含氟之蝕刻氣體以及氬氣之 混合氣體通入反應室中。上述之混和氣體更可以包含氧氣 以及一氧化碳（CO)。含氟之蝕刻劑之流量約爲5至50 seem。另外’氬氣之流量則約爲50至250sccm，CO氣 體之流量則約爲1 0至200 seem，氧氣之流量則約爲5 至20 seem。此蝕刻反應室可以爲磁場增強式反應性離子 (MERIE)反應室。含氟之蝕刻劑可以選自C4F8、CHF3、 CF4或上述任意組合所組成之族群之一。 於蝕刻過程中製程之壓力維持於10至60 mtorr。於 步驟120時，提供一功率約爲1000至2000W之電漿並 於此步驟中提供一磁場用以加速含氟之離子俾使該含氟 之離子具有較大之動量蝕刻氧化物。以最佳實施例而言， 磁場強度約爲50至200高斯。磁場加速離子之方向垂直 於底材之表面。 本紙張尺度適州中國國家標绰（CNS ) Λ4規格（210x 297公;| ) ------；--γ 裝------訂------^'4! {請先閱讀背而之;i-意事項再填苟本頁) 425632 B7 五、發明説明：：） 爲了提昇蝕刻之能力’ 一物理性轟擊亦同時用來撞 擊氧化物。例如’可以引入含Ar +離子物種之撞擊並保持 電漿與磁場於反應室中a此外’於蝕刻過程中反應室之溫 度維持於〇至2 5 之間。一直餘刻到曝露底材爲止3 最後一步驟130爲去除硬式罩幕。第三圖所示爲蝕 刻後之結果，接觸洞之厚度標記爲D。利用本發明可以製 作深度大於2.7微米之接觸洞。^ In the Ministry of Decoration, the jujube bureau Zhengong elimination co-operative cooperative seal # 4 256- ^ P v ίΓ V. Description of the invention () Officials use a-Si or a-Si: H as the hard cover 6 because of its plasma The process temperature of the deposited film is about 30CTC. The etching ratio of silicon oxide to a-Si or a-Si: H is about 10: 1 to 20: 1. Next, a photoresist 8 is formed on the hard mask 6 to define the pattern of the contact hole. Subsequently, the hard mask 6 is etched with the photoresist 8 as an etching mask to transfer the contact hole pattern into the hard mask 6. Photoresist can be selectively removed or left behind. Referring to the first figure, in step 110, a mixed gas of an etching gas containing fluorine and an argon gas is passed into the reaction chamber. The above-mentioned mixed gas may further include oxygen and carbon monoxide (CO). The flow rate of the fluorine-containing etchant is about 5 to 50 seem. In addition, the flow rate of argon gas is about 50 to 250 seem, the flow rate of CO gas is about 10 to 200 seem, and the flow rate of oxygen is about 5 to 20 seem. The etching reaction chamber may be a magnetic field enhanced reactive ion (MERIE) reaction chamber. The fluorine-containing etchant may be selected from the group consisting of C4F8, CHF3, CF4, or any combination thereof. During the etching process, the pressure of the process is maintained at 10 to 60 mtorr. At step 120, a plasma with a power of about 1000 to 2000 W is provided. In this step, a magnetic field is provided to accelerate the fluorine-containing ions, so that the fluorine-containing ions have a larger momentum to etch the oxide. In the preferred embodiment, the magnetic field strength is about 50 to 200 Gauss. The direction of the magnetic field acceleration ions is perpendicular to the surface of the substrate. Size of this paper: China National Standards (CNS) Λ4 specification (210x 297 male; |) ------; --γ Pack -------- order -------- ^ '4! { Please read the back; i-Issue before filling out this page) 425632 B7 V. Description of the invention: :) In order to improve the ability of etching 'a physical bombardment is also used to strike the oxide. For example, 'the impact of Ar + ion-containing species can be introduced and the plasma and magnetic field can be maintained in the reaction chambera. In addition', the temperature of the reaction chamber is maintained between 0 and 25 during the etching process. Until the substrate is exposed 3 The last step 130 is to remove the hard mask. The third figure shows the result after etching. The thickness of the contact hole is marked as D. The invention can be used to make contact holes with a depth greater than 2.7 microns.
°C 本發明以較佳實施例說明如上，而熟悉此領域技藝 者，在不脫離本發明之精神範圍內’當可作些許更動潤 飾，其專利保護範圍更當視後附之申請專利範圍及其等同 領域而定。 請先閲讀背面之注意事項再填寫本頁) 裝.° C The present invention is described above with a preferred embodiment, and those skilled in the art will be able to make a few changes and modifications without departing from the spirit of the present invention. Its equivalent field depends. (Please read the notes on the back before filling out this page).
，1T .¾¾.部中央榡準局只工消贽合竹衩印絮 氏張尺度州中咖家標4丨-(CNS ).Λ4ϋ~Πκ)χ297办), 1T. ¾¾. The Central Government Bureau of Standards and Technology only eliminates the combination of bamboo and Indian prints, and it is the standard of Chinese coffee in the state of Zhangzhou. 4 丨-(CNS). Λ4ϋ ~ Πκ) × 297)