4 2 69 8 4 a； B7 五、發明說明（1 ) 發明背景 發明領域 (請先間讀背面之注意事項再填寫本頁) 本發明係關於一種製造多層接觸窗之方法，特別係關於 一種運用抗反射層氮氧化矽以及鈦化合物層於製造多層接 觸窗之方法，其可以解決傳統方法所面臨之多層反射光及 蚀刻終點控制不易’以及微影製程视窗過小導致良率偏低 等問題。 先前技藝說明 隨著積體電路積集密度的增加，臨界尺寸（Criticai dimension，CD)不斷縮小，對於微影製程及蝕刻製程的要求 也持續增加’往更小的臨界尺寸，甚至往下一世代的臨界 尺寸前進更成為業界最大的挑戰。 經濟部智慧財產局員工消費合作社印制衣 半導體製程以近紫外光（Near UV，NUV)甚至深紫外光 (Deep UV，DUV)作為微影定義圖形曝光顯影的光源，隨著 線寬的臨界尺寸不斷變小，光源本身對於光罩圖形轉印至 矽晶圓上光阻的圖形解析度有莫大影響。以g_Une(436 nm)、i-line(365 nm)進步至KrF(248 nm)為例，波長縮小，使 得解析度（Resolution)增加’線寬的臨界尺寸因而得以縮 小，然而也造成焦距深度（Depth of Focus, DOF)變小，對焦 不夠準確將導致曝光不良，使微影製程控制不易。更由於 波長縮小，能量強度與線寬對光阻深度的擺盪曲線（Swing curve)擺盪幅度加大，線寬控制不易，且駐波效應顯著。 製造多層接觸窗的方法’由於線寬的進_步限縮 (Shrink)，以及不同深度的反射光干擾所引起的如臨界尺寸 本紙張尺度通用t因囷家標準（CNS)A.l規格（210 * 297公釐） 426984 A7 經濟部智慧財產局員X消費合作.社印製 B7 五、發明說明（2 ) CD變易大、均句性差、刻凹痕（Notching)現象及駐波現象 甚為嚴重；更由於蚀刻深度不同，造成蝕刻控制不易。在 製造多層接觸窗的過程中，微影的臨界尺寸CD控制因深 度的不同而變’也就是入射光到達第一反射面的距離不 同’造成反射光干擾的複雜性，因為當接觸窗的深度不同 時，來自下層的反射光干擾不一’造成每一個曝光區域線 寬曝光程度不同’線寬無法控制一致；另一方面，由於線 寬縮小，干擾程度相對加大’更因為深度不同，造成姓刻 深度終點難以控制等困難。 如圖1所示的傳統多層接觸窗結構，在矽基質丨i之上沈 積介電層13以及塗附圖案光阻I2 ;該介電層π 一般係矽氧 層如填碎玻璃（BPSG，Boro-phospho-silicate-glass)及 / 或四 乙基氧化梦（TEOS ’ Tetra-ethyl-ortho-sil.icate)或其它介電材 質。其中有由隔離層14以及矽化鎢15所定義的閘極以及多 晶矽16等元件材料；入射光17經過光罩未遮蓋區後穿透進 入介電層13，由於其光可穿透性，部分光線一直進到隔離 層U以及矽化鎢I5所定義的閘極以及多晶矽16而被反射穿 出介電層13表層，進而干擾光罩遮蓋區之光阻12，造成遮 蓋區光阻部分曝光；或者反射光與入射光形成干擾現象， 導致駐波效應，圖案剖面模糊波浪狀，製程控制不易。更 由於緊接的接觸窗蝕刻深度不一，致蝕刻終點不易控制； 若蝕刻過深，則光阻厚度阻擋不足或將過度蝕刻到位於較 淺位置的元件材料，如多晶矽16，而且蝕刻過度將使線寬 容易超出管制標準；若蝕刻深度不夠，較深位置的元件材 —5 ~ 本紙張尺度適用中國國家標準（CNS)A1蜆格497公餐） ----i---;---,「裝--------訂 (請先閱讀背面之注意事項再填寫本頁)4 2 69 8 4 a; B7 V. Description of the invention (1) Background of the invention (please read the precautions on the back before filling out this page) The present invention relates to a method for manufacturing multi-layer contact windows, especially to an application The anti-reflection layer silicon oxynitride and titanium compound layers are used in the method of manufacturing a multilayer contact window, which can solve the problems of conventional multilayer methods such as the difficulty of controlling the multilayer reflected light and the end point of etching and the low yield of the lithographic process window. The prior art shows that as the density of integrated circuits increases, the critical dimension (CD) continues to shrink, and the requirements for lithography and etching processes continue to increase. 'To smaller critical dimensions, and even to the next generation Advancing the critical dimension has become the industry's biggest challenge. The Intellectual Property Bureau employee consumer cooperative of the Ministry of Economic Affairs of the printed clothing semiconductor manufacturing process uses near ultraviolet (NUV) or even deep ultraviolet (DUV) as the light source for the development of lithographic definition graphics exposure. With the critical size of line width, It becomes smaller, and the light source itself has a great influence on the resolution of the photoresist on the silicon wafer. Taking g_Une (436 nm) and i-line (365 nm) to KrF (248 nm) as an example, the wavelength shrinks, which increases the resolution (Resolution), the critical size of the line width is reduced, but it also causes the focal depth ( Depth of Focus (DOF) becomes smaller. Inaccurate focusing will result in poor exposure, making it difficult to control the lithography process. As the wavelength shrinks, the swing amplitude of the Swing curve of the energy intensity and line width to the depth of the photoresistance increases, the line width control is not easy, and the standing wave effect is significant. The method of manufacturing a multilayer contact window 'is due to the line width's shrinkage (shrink) and reflected light interference at different depths, such as the critical size. The paper size is universal. Due to the family standard (CNS) Al specification (210 * 297 mm) 426984 A7 Member of the Intellectual Property Bureau of the Ministry of Economic Affairs, X Consumer Cooperation. Printed by B7. V. Invention Description (2) The CD becomes easy to enlarge, the sentence is poor, the notching phenomenon and the standing wave phenomenon are very serious; more Due to the different etching depths, it is not easy to control the etching. In the process of manufacturing a multilayer contact window, the critical dimension CD control of the lithography changes due to different depths, that is, the distance of the incident light reaching the first reflecting surface is different, which causes the complexity of reflected light interference, because when the depth of the contact window At the same time, the interference of reflected light from the lower layer is different, which causes the line width of each exposure area to be different. The line width cannot be controlled uniformly. On the other hand, the line width is reduced and the interference level is relatively large. It is difficult to control the deep end of the last name and so on. As shown in FIG. 1, a conventional multilayer contact window structure has a dielectric layer 13 and a patterned photoresist I2 deposited on a silicon substrate i; the dielectric layer π is generally a silicon-oxygen layer such as shattered glass (BPSG, Boro -phospho-silicate-glass) and / or TEOS 'Tetra-ethyl-ortho-sil.icate or other dielectric materials. Among them are the gate material defined by the isolation layer 14 and tungsten silicide 15 and polycrystalline silicon 16; the incident light 17 penetrates the dielectric layer 13 after passing through the uncovered area of the photomask. Due to its light penetrability, part of the light All the way to the gate defined by the isolation layer U and tungsten silicide I5 and polycrystalline silicon 16 are reflected through the surface of the dielectric layer 13 and then interfere with the photoresist 12 in the masking area of the mask, causing partial exposure of the photoresist in the masking area; or reflection The interference phenomenon between light and incident light leads to standing wave effect, the pattern section is blurred and wavy, and the process control is not easy. Furthermore, the contact depths of the contact windows are not the same, which makes it difficult to control the end of the etching. If the etching is too deep, the thickness of the photoresist will be insufficient or it will be over-etched to the element materials located at a shallower position, such as polycrystalline silicon 16, Make the line width easy to exceed the control standards; if the etching depth is not enough, the component materials in deeper positions-5 ~ This paper size applies to the Chinese National Standard (CNS) A1 grid 497 meals ---- i ---;- -, "Install -------- order (please read the precautions on the back before filling this page)
4269 8 4 五、發明說明（3 ) 料因為介電層13殘留將導致㈣塞接觸窗接觸不良。 美國專利號碼第4,758,305號提出的接觸窗㈣方法，使 用多重光阻以及過度曝光和過度顯影來製造間隙壁層，無 需任何硬罩幕層，可適用於…以⑶㈣的圖案；其係 以多重光阻的方式製作接觸窗，而且只針對一種接觸窗， 並不探討、且無法解決多層接觸窗的問題。美國專利號碼 第5,355,020號提出具有多層金屬接觸窗的半導體元件，其 中運用到平坦化及抗反射技術；其所定義的多層金屬接觸4269 8 4 V. Description of the invention (3) It is expected that the contact of the congestion contact window will be poor because the dielectric layer 13 remains. U.S. Patent No. 4,758,305 proposes a method of contact window sills, which uses multiple photoresistors and overexposure and over-development to produce the spacer wall layer without any hard cover curtain layer. It can be applied to ... in the pattern of ⑶㈣; The contact window is made in a resistive manner, and it is only for one contact window. It does not discuss and cannot solve the problem of multi-layer contact windows. U.S. Patent No. 5,355,020 proposes a semiconductor element with a multilayer metal contact window, which uses planarization and anti-reflection technology; its definition of a multilayer metal contact
窗的多層是指金屬線多|，其平坦化及抗反射技術是應用 在金屬線上的製程D 對於夕層接觸窗因應不同需求而有不同深度之接觸窗孔 洞，所造成接觸甯曝光孔徑控制不易的困難，習知技術並 丧法提供一良好的解決方案。 發明目的及概诚 針對習知技術的問題’本發明提出一種新穎且具產業實 用性的製造多層接觸窗的方法’著重在解決多層接觸窗因 為從不同深度而來的底層反射光所導致的各種問題。 本發明之一目的在提供一種製造多層接觸窗之方法，其 以抗反射層作為硬罩幕（Hard mask)，其可避免上述先前技 藝因為線寬縮小使得曝光光源干擾效應加大，以及因為多 層接觸窗的深度不同，反射光線干擾控制不易，使得微影 製程控制困難的缺陷，以克服多層深度反射光線的干擾； 並且對於微影及蝕刻製程之臨界尺寸（CD)能達到良好的控 制效果，可以加大微影製程視窗以及提高產品良率，進一 -6 - 本紙張足度適用中國國家標準（CIs’S)A-l規格（210 X 297公S ) I n ,1— ^1— —1· I 1 .^1 n 一 4 n I (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 A7 4269 8 4 B7 五、發明說明（4 ) 步更可以往下一世代縮小線寬製程前進；再者，可以避免 製造多層接觸窗時，由於蝕刻深度的不同，蝕刻時間過長 所造成光阻過度蝕刻而流失之問題。 為達成上述目的’本發明揭示於製造多層接觸窗時藉由 沈積反射層以及抗反射層，由於反射層的反射作用，使得 反射光一律被反射’將多重深度的反射光簡化成單一深度 反射光，因而更容易控制；另一方面，該反射光透過抗反 射層對於光線做180Q的相位差轉換，因而互相抵消。再 者，此沈積之反射層以及抗反射層可作為姓刻製程的硬罩 幕之用’可避免因為多重接觸窗深度不同，蝕刻終點要求 不同所導致触刻不足或蚀刻過度的問題。抗反射技術雖然 是形成金屬線的熟知技術，但是針對多層接觸窗孔洞形成 時有如此堆疊之方法者卻屬本發明首創。 圖式簡單說明 圖1所示為習知之多層接觸窗結構。 圖2所示為本發明抗反射層削減反射光干擾原理。 圖3所示為本發明沈積反射層及抗反射層堆疊於傳統多 層接觸窗之結構。 圖4所示為本發明本發明使用反射層及抗反射層塗作以 減少多重接觸窗製作過程中反射光干擾的具體實施例步 騾；其中 圖4a描述先行塗佈反射層及抗反射層，接著進行接觸窗 的微影、蝕刻等接觸窗圖案製作； 圖4b描述蝕刻多層接觸窗氧化層； -7 - 度適用中因國家楳準（CNS)/V1規格（210 X 297公釐)~~ ----------------J!裝· ！ (請先閱讀背面之注意事項再填寫本頁) . 經濟邨智慧財產局員工消費合作社印制^ Λ7The multi-layer of a window refers to a large number of metal lines. Its flattening and anti-reflection technology is a process applied to metal lines. For the contact layer of the window, the contact window holes have different depths due to different needs, which makes it difficult to control the exposure aperture. Difficulties, know the technology and provide a good solution. The purpose of the present invention is to address the problems of the conventional technology. The present invention proposes a novel and industrially practical method for manufacturing multi-layer contact windows. It focuses on solving various problems caused by multi-layer contact windows caused by reflected light from the bottom layer from different depths. problem. An object of the present invention is to provide a method for manufacturing a multi-layer contact window, which uses an anti-reflection layer as a hard mask, which can avoid the above-mentioned prior art to increase the interference effect of the exposure light source due to the reduced line width, and because of the multilayer The depth of the contact window is different, and the interference of reflected light is not easy to control, which makes it difficult to control the lithography process to overcome the interference of multiple layers of deeply reflected light; and it can achieve a good control effect on the critical dimension (CD) of the lithography and etching process. The lithographic process window can be enlarged and the product yield can be increased. -6-This paper is fully compliant with the Chinese National Standards (CIs'S) Al specifications (210 X 297 male S) I n, 1— ^ 1— —1 · I 1 . ^ 1 n 1 4 n I (Please read the notes on the back before filling out this page) Printed by the Consumers' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 4269 8 4 B7 V. Description of invention (4) Steps can be carried forward to the next generation The process of reducing the line width progresses; further, it can avoid the problem of photoresist over-etching due to the difference in etching depth and long etching time when manufacturing multilayer contact windows. In order to achieve the above object, the present invention discloses that the reflective light is uniformly reflected due to the reflection effect of the reflective layer by depositing a reflective layer and an anti-reflective layer when manufacturing a multilayer contact window. Therefore, it is easier to control; on the other hand, the reflected light passes through the anti-reflection layer to perform 180Q phase difference conversion on the light, and thus cancel each other out. Furthermore, the deposited reflective layer and anti-reflection layer can be used as a hard mask for the last name engraving process', which can avoid the problems of insufficient contact or excessive etching due to different depths of multiple contact windows and different requirements of the etching endpoint. Although the anti-reflection technology is a well-known technology for forming metal lines, it is the invention of the present invention that a method for stacking such a multilayer contact window hole is formed. Brief Description of the Drawings Figure 1 shows a conventional multilayer contact window structure. FIG. 2 shows the principle of reducing interference of reflected light by the anti-reflection layer of the present invention. FIG. 3 shows a structure in which a reflective layer and an anti-reflective layer are stacked on a conventional multi-layer contact window according to the present invention. FIG. 4 is a specific embodiment of the present invention using a reflective layer and an anti-reflective layer to reduce the interference of reflected light during the manufacturing process of multiple contact windows; FIG. 4a illustrates the prior application of the reflective layer and the anti-reflective layer, Next, the contact window pattern making such as lithography and etching of the contact window is performed; Figure 4b depicts the etching of multiple contact window oxide layers; -7-The applicable national standards (CNS) / V1 specifications (210 X 297 mm) ~~ ---------------- J! Outfit! (Please read the precautions on the back before filling out this page). Printed by the Consumers Cooperative of the Economic Village Intellectual Property Bureau ^ Λ7
4269 8 4 經濟部智.¾財A局員工消費合作社印製 五、發明說明（5 ) 圖4c描述移除光阻及抗反射層； 圖4d描述製作多重接觸窗金屬插塞； 圖4e描述後續接觸窗上之金屬線佈線製作。 元件符號對照 11 矽基質 12 光阻 13 介電層 14 隔離層 15 石夕化鶴 16 多晶矽 17 入射光 21 入射光 22 第一反射光 23 第二反射光 24 抗反射層 25 下層反射層 31 入射光 32 抗反射層 33 反射層 71 屏障金屬 72 鹤插塞： 81 金屬層 82 氮化鈦 發明詳細說明 為了解決習知製造多層接觸窗的方法中反射光的干擾以 及多重接觸窗深度蝕刻差異的困難，本發明結合反射層以 及抗反射層形成單層深度反射光，更造成硬幕罩效果，以 克服習知技藝問題，可以有效地應用在半導體製程，例如 動態隨機存取記憶體的製造過程中" 為了達成上述目的，本發明揭示一種製造多層接觸窗之 方法，包含下列步驟：提供一介電層於一基材上，於該基 材上不同高度之處並形成有多數個元件；形成—反射層於 | 該介電層上，·形成一抗反射層会該反射層上；以及蚀刻該 -8 - 本紙張尺度滷用尹國國家標準（C‘NS)如規格X烈7公f ) ----„--------Ji-裝--------訂- {請先閲讀背面之注意事項再填寫本頁) 4269 8 4 A7 經濟郤智慧財產局員工消費合作社印製 •________B7 _____ 五、發明說明（6 ) 介電層並形▲多數個接觸窗，其中係以該反射層以及抗反 射層作為蝕刻的硬罩幕，且該等接觸窗的底部與該等元件 個別地相抵接。於一較佳實施例中，該反射層係選自鈦及 氮化鈦’該抗反射層係氮氧化矽。 進一步而言’本發明更揭示一種製造半導體元件之方 法’包含下列步驟：於一基材上形成多數個元件；形成一 抗反射層氮氧化矽層以及一反射層鈦化合物層於該基材 上，以及蚀刻並形成多數個多層接觸窗於該基材上，其中 係以該反射層以及抗反射層作為蝕刻的硬罩幕，且該等接 觸窗的底部與該等元件個別地相抵接。 以圖2舉例說明抗反射層削減反射光干擾的原理；入射 光21進入光阻12後部分被吸收以進行光化學曝光反應，部 分被抗反射層24頂層所反射而形成第一反射光22，部分入 射穿透抗反射層24而被下層反射層25所反射而形成第二反 射光23並回到光阻12 ;藉由控制抗反射層24的厚度、折射 率（Refractive index, η)及消失係數（Extinction coefficient, k)， 可以控制第二反射光23與入射光21或第一反射光22的相位 差為二分之一波長，即180G，二者互相抵減，可以去除反 射光干擾。 圖3進一步顯示說明本發明如何藉由沈積反射層及抗反 射層堆疊於傳統多層接觸窗結構上，消除多重反射干擾的 問題。首先，於置備多層接觸窗底材介電層13上沈積反射 層33，接著沈積抗反射層32於其上，並塗佈一層光阻12 ; 該介電層一般係BPSG及/或TEOS或其它介電材質。進行多 -9 一 本紙張尺度適用f國iT家標準（CNS)zVl規格m〇x297公釐） 1· Ϊ _^i I n II - I 1 n I 一 β* « (請先閱讀背面之注意事項再填寫本頁) 42698 4 A7 經濟部智慧財產局員工消費合作社印*''农 _ B7____五、發明說明（7 ) 層接觸窗光罩圖形製作曝光時，入射光31穿透光罩非遮蓋 區後進入抗反射層32以及反射層33，反射層33將所有穿透 光反射回抗反射層32，光線不再穿透進入介電層13，不會 有多重深度反射光的困擾，將多重深度的反射光整合成單 一深度的反射光，得以簡化反射光的複雜問題；另一方 面’抗反射層32反射的第一反射光與反射層33反射的第二 反射光相位差較佳地係180Q而彼此削減，進一步將反射光 干擾削減，此相位差可藉由抗反射層32的膜厚、折射率以 及消失係數配合使用光源的波長等所控制。在多重接觸窗 的製造過程中，如此的製程設計使得微影曝光及顯影階段 所產生的反射光千擾得以解決，至於蚀刻製程階段，抗反 射層32以及反射層33的沈積’特別是反射層33，可作為硬 罩幕之用’抵擒蝕刻過程中由於蚀刻深度不同所可能造成 的蝕刻過度問題》 以下，參考圓4詳細說明本發明之一具體實施例之步 驟。首先，沈積反射層33於介電層13之上，此反射層33可 以選自鈦，或鈦加氮化鈦，選擇的考量以及差異在於前層 材質的黏著性。接著再沈積抗反射層32，此抗反射層32， 並予以進行微影圖案製作；於一具體實施例中，抗反射層 32係選自氮氧化矽；抗反射層的厚度約為2〇〇埃至ι〇⑼埃 之間，較佳者為28〇埃至310埃之間。接著，去除抗反射層 32及抗反射層33，其壓力為〇‘〇1毫托耳（mT)至1〇毫托耳之 間，使用 1%-40%CH4，1%_20%CHF3，1% 5〇%Bci3 , ‘ 3〇%Cl2，l%-80%Ar或1%_20%〇2氣體化學蚀刻曝光區之抗反 -10 - ----.------I iw--裝----tf---訂· (請先閱讀背面之注意事項再填寫本頁) 本紙張K度適用中國囹Ί標準（CNS)A4規烙（21ϋ X 297公 4269 8 δ A7 _______B7_________ 五、發明說明（8 ) 射磨32及抗反射層33，如圖4a所示。該银刻方法係一般業 界人士所常用’熟知技術人士運用本身技術思想當能輕易 推想而知。 隨後蝕刻多層接觸窗内之氧化層，將接觸窗打開，如圖 4b所示。此時蝕刻過程，沈積的反射層33以及抗反射層32 能防止因為接觸窗蝕刻深度不一所可能造成的蝕刻差異， 避免光阻抵擒不住蚀刻而流失導致破壞到介電層13的表 層’以及因為蝕刻不一致而影響圖案的正確度等問題。蚀 刻不足，接觸窗蝕刻不夠深’導致接觸窗内殘留未開，蝕 刻過度’除了破壞接觸窗底層物質外，接觸窗大小不一， 亦造成製程的困難，降低產品良率。 接著，蝕刻移除光阻及氮氧化矽，其壓力為lmT至 200π\Τ 間’使用 1%-25%CF4，l%-80%Ar，l%-250/〇CHF3，或 經濟部智慧財產局員工消費合作社印製 ----.---.---y-— 裝--------訂· (請先閱讀背面之注意事項再填寫本頁) 1%-35%〇2氣體化學進行蚀刻去除，以利接著沈積物的沈 積’如圖4c所示。蝕刻終點停在反射層33。隨後，進行沈 積屏障金屬71及鎢72等鎢插塞製造過程，如圖4cl所示。最 後’沈積金屬層81及抗反射層氮化鈦82並進行金屬圖案製 作，如圖4e所示；其中，該金屬層81可以選自鋁銅合金或 鋼金屬等。 藉由本發明所揭示的一種以抗反射層作為硬罩幕之製造 多層接觸窗方法’可以避免習知技藝的缺點，可以有效控 制製程，避免光干擾以及#刻控制不易等問題，對於製造 更先進的微小尺寸記憶體有莫大的幫助。 以上所述之詳細說明，僅為本發明之較佳樣態而已，並 -11 - 本紙張尺度適用中國國家標革（CNS)A'.l規格（2〗〇x 297公f ) ' ' 42S984 A7 ___B7 五、發明說明（9 ) 非據以限定本發明之保護範園；凡其它未脫離本發明所揭 示精神下之衍生或改變，均應該由下列所述明之申請專利 範圍所界定。 ----.---.-----裝--------訂· (請先閲讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印制^ 本紙張尺度適用t园國家標準（CNS)A:1規格（210 X 297公釐）4269 8 4 Wisdom of the Ministry of Economic Affairs. ¾ Printed by the Consumer Cooperative of Finance Bureau A. 5. Description of the invention (5) Figure 4c describes the removal of the photoresist and anti-reflection layer; Figure 4d describes the production of multiple contact window metal plugs; Figure 4e describes the follow-up Manufacture of metal wiring on the contact window. Component symbol comparison 11 silicon substrate 12 photoresist 13 dielectric layer 14 isolation layer 15 Shi Xihua Crane 16 polycrystalline silicon 17 incident light 21 incident light 22 first reflected light 23 second reflected light 24 anti-reflection layer 25 lower reflection layer 31 incident light 32 Anti-reflection layer 33 Reflective layer 71 Barrier metal 72 Crane plug: 81 Metal layer 82 Titanium nitride The invention is explained in detail in order to solve the interference of reflected light in the conventional method of manufacturing multilayer contact windows and the difficulty of etching depth differences in multiple contact windows. The present invention combines a reflective layer and an anti-reflection layer to form a single layer of deeply reflected light, which also creates a hard curtain effect to overcome the problems of conventional techniques and can be effectively applied to semiconductor processes, such as the manufacturing process of dynamic random access memory & quot In order to achieve the above object, the present invention discloses a method for manufacturing a multi-layer contact window, comprising the following steps: providing a dielectric layer on a substrate, and forming a plurality of elements at different heights on the substrate; forming— A reflective layer on the dielectric layer, forming an anti-reflective layer on the reflective layer; and etching the -8-paper ruler National Standard (C'NS) for halogens such as specification X fierce 7 male f) ---- „-------- Ji-installation -------- Order-{Please read the back first Please note this page, please fill out this page) 4269 8 4 A7 Printed by the Consumers ’Cooperative of the Economic and Intellectual Property Bureau • ________B7 _____ V. Description of the invention (6) Dielectric layers are formed ▲ Most of the contact windows are the reflective layer and The anti-reflection layer is used as an etched hard cover, and the bottom of the contact windows and the elements individually abut. In a preferred embodiment, the reflective layer is selected from titanium and titanium nitride. It is a silicon oxynitride. Further, the present invention further discloses a method for manufacturing a semiconductor device, which includes the following steps: forming a plurality of devices on a substrate; forming an anti-reflective silicon oxynitride layer and a reflective titanium compound layer On the substrate, a plurality of multilayer contact windows are etched and formed on the substrate, wherein the reflective layer and the anti-reflection layer are used as an etched hard mask, and the bottom of the contact windows is separate from the components. The ground is in contact. An example of the anti-reflection layer is shown in Fig. 2 to reduce the interference of reflected light. After the incident light 21 enters the photoresist 12, it is partially absorbed for photochemical exposure reaction, partly reflected by the top layer of the anti-reflection layer 24 to form the first reflected light 22, and part of the incident light penetrates the anti-reflection layer 24 and is reflected by the lower layer. The second reflected light 23 is reflected by the layer 25 and returns to the photoresist 12; by controlling the thickness, refractive index (Refractive index, η) and extinction coefficient (k) of the anti-reflection layer 24, the second The phase difference between the reflected light 23 and the incident light 21 or the first reflected light 22 is a half wavelength, that is, 180G. The two cancel each other out, and the reflected light interference can be removed. FIG. 3 further illustrates how the present invention eliminates the problem of multiple reflection interference by depositing a reflective layer and an anti-reflective layer on a conventional multilayer contact window structure. First, a reflective layer 33 is deposited on the dielectric layer 13 of the multi-layered contact window substrate, and then an anti-reflection layer 32 is deposited thereon, and a photoresist 12 is coated; the dielectric layer is generally BPSG and / or TEOS or other Dielectric material. Multi--9 A paper size applies to the country's iT home standard (CNS) zVl specification m〇x297 mm) 1 · Ϊ _ ^ i I n II-I 1 n I a β * «(Please read the note on the back first Please fill in this page again for details) 42698 4 A7 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs *` `Farm _ B7 ____ V. Description of the invention (7) When the exposure pattern of the layer contact window mask is exposed, the incident light 31 penetrates the mask After covering the area, it enters the anti-reflection layer 32 and the reflective layer 33. The reflective layer 33 reflects all the penetrating light back to the anti-reflection layer 32. The light no longer penetrates into the dielectric layer 13, and there is no trouble of multiple deep reflected light. Multiple depths of reflected light are integrated into a single depth of reflected light to simplify the complex problem of reflected light; on the other hand, the phase difference between the first reflected light reflected by the anti-reflection layer 32 and the second reflected light reflected by the reflective layer 33 is better Each of them is reduced to 180Q, and the interference of reflected light is further reduced. This phase difference can be controlled by the thickness of the anti-reflection layer 32, the refractive index, and the extinction coefficient in combination with the wavelength of the light source. During the manufacturing process of the multiple contact window, such a process design allows the reflected light interference generated during the lithographic exposure and development stages to be resolved. As for the etching process stage, the deposition of the anti-reflection layer 32 and the reflection layer 33, especially the reflection layer 33. It can be used as a hard cover screen to counteract the problem of over-etching which may be caused by different etching depths during the etching process ". Hereinafter, the steps of a specific embodiment of the present invention will be described in detail with reference to circle 4. First, a reflective layer 33 is deposited on the dielectric layer 13. The reflective layer 33 can be selected from titanium, or titanium plus titanium nitride. The considerations for selection and the difference are the adhesion of the material of the front layer. Next, an anti-reflection layer 32 is deposited, and the lithography pattern is made. In a specific embodiment, the anti-reflection layer 32 is selected from silicon oxynitride; the thickness of the anti-reflection layer is about 200. Between Angstrom and ι〇⑼ang, preferably between 28 Angstrom and 310 Angstrom. Next, the anti-reflection layer 32 and the anti-reflection layer 33 are removed, and the pressure is between 0 '〇1 millitorr (mT) to 10 millitorr, using 1% -40% CH4, 1% _20% CHF3,1 % 50% Bci3, '3 %% Cl2, 1% -80% Ar or 1% _20% 〇2 gas chemical etching exposure area anti-reflection -10-----.------ I iw- -Packing ---- tf --- Order · (Please read the precautions on the back before filling this page) The K degree of this paper applies the Chinese standard (CNS) A4 (21ϋ X 297 male 4269 8 δ A7 _______B7_________ V. Description of the invention (8) Abrasion grinding 32 and anti-reflection layer 33, as shown in Fig. 4a. The silver engraving method is commonly used by ordinary people in the industry. The oxide layer in the contact window opens the contact window, as shown in Fig. 4b. At this time, during the etching process, the deposited reflective layer 33 and the anti-reflection layer 32 can prevent the etching difference that may be caused by the different etching depth of the contact window, and avoid The photoresist cannot resist the loss of etching, leading to damage to the surface layer of the dielectric layer 13 and the inaccuracy of the etching and affecting the accuracy of the pattern. The contact window is not etched deeply enough, which causes the contact window to remain unopened and excessive etching. In addition to destroying the underlying material of the contact window, the size of the contact window is different, which also causes difficulties in the process and reduces the product yield. Next, the photoresist and nitrogen are removed by etching. Silicon oxide, the pressure of which is between lmT and 200π \ T 'Use 1% -25% CF4, 1% -80% Ar, 1% -250 / 〇CHF3, or printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs --- -.---.--- y-— Install -------- Order · (Please read the notes on the back before filling in this page) 1% -35% 〇2 gas chemistry to remove by etching The subsequent deposition of the deposit is shown in FIG. 4c. The end point of the etching stops at the reflective layer 33. Subsequently, the tungsten plugs such as the barrier metal 71 and tungsten 72 are deposited, as shown in FIG. 4cl. Finally, the metal layer 81 is deposited And an anti-reflection layer of titanium nitride 82 and metal patterning, as shown in FIG. 4e; wherein the metal layer 81 may be selected from an aluminum-copper alloy or a steel metal, etc. According to the present invention, an anti-reflection layer is used as a hard material. The method of manufacturing a multi-layer contact window of a curtain can avoid the shortcomings of conventional techniques and can effectively control the process. Free from light interference and #not easy to control, it is of great help to make more advanced micro-size memory. The detailed description above is only the best aspect of the present invention, and -11-this paper size Applicable to China National Standard Leather (CNS) A'.l specifications (2) 0x 297 male f) '42S984 A7 ___B7 V. Description of the invention (9) It is not intended to limit the scope of protection of the invention; all others do not depart from this Derivatives or changes under the spirit of the invention should be defined by the scope of patent application described below. ----.---.----- Installation -------- Order (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economy ^ Paper size applies to National Park Standard (CNS) A: 1 (210 X 297 mm)