201123295 六、發明說明： 【發明所屬之技術領域】 本發明侧於-種形成_的方法，尤指種在形細案時，避 免硬遮罩沾附银刻反應物的方法。 【先前技術】 積體電路或微機電系統之製作係利用一半導體基底，如硬晶圆， 並反覆經歷數百道的薄膜沉積、氧化、微影、爛與推雜等不同製 =>成。在微影和_製程中，包括形成圖案化之光阻於基板 t膜’及藉侧轉移光阻之圖案至下面的薄膜。然而，隨 ^寸=縮小，微影纽的解析度也需配合提升，目前所使用的方 恤辑編難，_㈣數值孔徑允 4 乂间析度，但會使得投射入光阻的影像焦深卿出0版㈣ 減小，導致圖案化光阻層變薄。 會騎大部糾赌化光阻 具有比光阻目材 製程#，使用硬遮罩來代替光阻，因為硬遮罩 板上㈣描爛性，所以利用硬遮罩作為遮罩來蚀刻基 硬遮硬料較不會在_時耗損，而影__的圖案。 1圖复合材料層’例如：氮化石夕、氮氧化石夕和氧化，第 所八，__y、S7F的及習知圖案化硬遮罩之方法示意圖。如第1圖 Μ、—f羞寺韻刻之材科層】〇上覆有一硬遮罩12，包含一氧化石夕層 一化石场16和-I化石夕層18由下至上覆蓋，接著利用微 201123295 办和韻刻製程’先於 再圖案化硬麵12:之後=:=!^嚷未示）， 中的圖案化之硬料2G。 ’冼可以形成如第2圖 圖案之硬解2G的輪_相為各相 的不同而於開口處產生輪廊不平 ;產物 之圖案在侧之後無法射轉印至待糊^遮罩20 【發明内容】 =2發賴—獅撕姆，佩上述問題。 首較佳實施例’本發明提供一種形成圖案的方法， :Γ::Γ刻之材料層，材料層可以為待形成金屬内連線的介 電層’接者在材料層上形成贿化硬遮罩，其t_化硬遮罩可以 為夕層或是單層結構，賊，再進行—爾理製程，此聽理製程 可以包錢化製程、氧化製程或光化韓射製程，接著再_處理過 後的圖案化硬遮罩作為遮罩，蝕刻材料層。 根據本發明之另-較佳實關，硬鮮係峨化销、氮氧化石夕 層、氣化鈦層和鈦金麟之任意組合所構成。使概化製程處理過 後’鈦金屬層之表面會轉化成氮化鈦。 根據本發明之又-較佳實施例，_所仙的機台之兩電極之間 的距離係介於26毫米至33毫米之間。 根據本發明之又-紐實施例，_時的操作轉為5Q瓦至15〇 201123295 瓦。 根據本發明之再-較佳實施例，领刻時通入氮氣作為輸送氣趙。 本發明之特色在於_健理_案化硬遮罩的表面性質改 變，使得在侧材料層時，圖案化硬遮罩不會不利地(牆⑽w和姓 刻氣體反應產生_物，造細案化硬遮罩變形並錢得赖刻殘留 物累積於圖案化硬遮罩上。 本發明之另-特色在於有數種可避免随化硬遮罩變形方式可 以單獨或混合使用，以加強效果。 【實施方式】 第3圖至第6圆繪示的是本發明之形成圖案的方法。如第3圖玲 示，首先，提供-顧刻之材料層3G，例如包含介電層％和低介 電材料層36 ’待韻刻之材料層3〇係位於一金屬内連線層％之上 方，其中-金屬内連線37位於金屬内連線層32 t，舉^而言，金 屬内連線37可以為單鑲嵌金屬導線錢職金料線，或是其它士 金屬插塞之導電元件u接著依序形成硬遮罩層35，硬遮罩層^y 少包含-含金制子材料，硬遮罩層35可以由選擇性之 仙、選擇性金制42、統鈦層44、選擇性之氮氧切層柄曰 ^選擇性之乳切層48由下至上堆疊所組成的複合材料層於材料 層3〇上’接著湘_化之光_未示），再圖案化硬遮罩㈣， 之後去除随化之絲，就可以形成如第4圖中的_化硬遮單 犯。值得注4的是：硬鮮％帽擇性的氧切層Μ、選擇 氮乳化糾46、氮化鈦層44和選擇性的鈦金屬層42在侧時皆被 201123295 蝕穿直至曝露出選擇性的氮氧化矽層4〇，而選擇性的氮氧化矽層 4〇只有部分被移除，也就是說，選擇性的氮氧化石夕層40下的低介 電材料層36並未曝露出來，依然被氮氧化石夕層4〇遮蔽，因此在去 除光阻的步驟時低介電材料層36不會受到不利的影響。又，硬遮罩 ^的材料可依應力、抗反射能力、黏著性、抗侧能力"·等因素考 量而採用上述材料或上述材料與其他材料的任意組合。例如，不同 硬遮罩材料可具有不同的應力類型如拉伸應力與收縮應力，使得硬 遮罩材料的總應力不會對下方待触刻材料層造成過大的拉伸或收縮 影響，因此減少脫層的風險。 根據本發明之另—較佳實關，其中魏刻之材料層30亦可以 包含轉體材料、導電材料或者是功函數材料等，而欲產生的圖案 可以是通孔、溝槽、線條或區塊。而圖案化硬遮罩％中的鈦金屬層 42可以依不同製程需求，得變更為组、鑭、稀土元素或過渡金屬元 素，氮化鈦層44亦可使用其它金屬氮化物或金屬氧化物來代替如氮 化组、氧化紹等。另外，圖案化硬遮罩38中也可另包含有機材料例 _如光阻’且圖案化硬遮罩38的材料組成可以為其他多層結構或單層 …構此外，本發明之方法可應用於半導體製程中各種需要使用硬 遮罩_刻製程，在下文所舉的實施例為製作金屬内連線時的應 用，而其它如閘極定義或是雙鑲嵌製程也可使用本發明之方法。告 圖案化硬鮮％的材料包含感光材f如光叫係藉㈣案化^ 罩35以形成圖案化硬遮罩38，其步驟係利用微影製程即曝光與顯 影步驟之組合來加以達成，且在圖案化硬遮罩％後毋需 步驟。 201123295 如第5圖所示’在形成圖案化硬遮罩％之後，接著進行 王· 5〇，如進行氮化製租，對圖案化硬遮罩％曝露在空間之 =行氮化處理，形成_化硬遮罩38,，縣_化硬遮㈣中 曝露的選擇性的氮氧切層4G '選擇性的鈦金屬層42、氮化 44、選擇性的氮氧化料46和選擇性的氧切層48在處 氮形成鍵細成缝化物，尤錄躲意岐錢化餘，吏目、 的是要使_化硬料38中，曝露在空間之中的鈦金屬層仏 就是鈦金屬層42的側壁表面形成氮化鈦&，另外，氮氧化石夕㈣ 之上表面和側壁表面也同時被氮化。氮化製程係使用紐•曰，发 插作的較佳條件為操作鮮2千7百萬賊或6千萬 ^ 至15秒反應。 逆订川 最後’如第6騎示，以預處理後之圖案化硬遮罩％，為遮罩， 钮刻材料層30 ’完成圖案轉移。因為圖案化硬遮罩％，和圖案化硬 遮罩38’表面的氮化物在_過程中被消耗，所以在第6圖中 留下部分的_化硬料38,。_材料層3Q之步驟可以在圖率化 硬遮罩戰化處理之彳_(in_situ贿，妓離伽蠢)進行。 則述的預處理S0可以依不同製程需求更改為氧化製程或使用光 化輪射製程如紫外光照射或是其它可以改變圖案化硬遮罩犯的表 面特性(化學性質或物理性質)如之製程，舉例而言，經過氧化處理 之後的圖案化硬遮罩38，的臨界尺寸可以縮小；而在紫外光照射之 後的所形成_案化硬遮罩38,中的馳續，使得硬度增加，以 在後續的蝕刻步驟提供更佳的遮蔽效果。 第 7圖繪示的是圖案化硬遮罩變形之 示意圖，其中相同的元件以 201123295 相同的符號表示，傳統蝕刻材料層的步驟中，通常是使用碳氟化合 物作為勉刻氣體，例如四氟化碳、三敗甲燒、六氟乙辟，在碳氣 化合物被電離之後，齡軸轉，其中包含_子、碳氟化合物 的自由基等。然而，習知製程在姓刻材料層之前，並沒有對圖案化 硬遮罩進行預處理’ g此，如第7圖所示，在利用電隸刻時，未 處理的欽金屬層42喊面會和氟離子發生反應，形成敗化鈦凸起物 54等之β彳產物附著在鈦金屬層μ的表面上，之後會使得餘刻殘留 物如碳氟高分子聚合物56淤積在圖案化硬遮罩38之側壁，造成圖 案化硬遮罩38變形，改變所欲定義之開口的大小，進而嚴重影響姓 刻效果。和習知技術不同的是：本發明利用預處理，將欽金屬層42 的表面轉變為氮化鈦，降低鈦金屬層與侧氣體反應的可能性，故 了有效避免產生氣化欽凸起物54。 第8圖綠示的是習知之材料層_刻後發生碗形輪廊之示意 圖’其中相同的元件以相同的符號表示。於傳統步驟中，因為圖案 化硬遮罩的_速率和材料層相差過大，因此，在侧後會形成碗 形輪卿騰娜啊岭若以第旧中的圖案化硬遮罩犯由選擇 性的氮氧化石夕層40、選擇性的鈦金屬層42、氣化欽44、選擇性的 氮氧⑽46和._氧化耗所猶為例，在未_預處理5〇 之則的選擇性的氮氧化石夕層4〇之侧速率較低介電材料％小，因 此’在侧時’低介電材料36就會被姓刻較多，而氮氧化石夕層卯 被餘刻較少，進而造成如第8圖中以圓圈標示的碗形娜泣。如第 圖斤示本發月中進行預處理5〇之後所形成的圖案化硬遮罩％， 之表質丨生質改1 ’使得圖案化硬遮罩38,的钮刻速率和材料層％拉 201123295 近，尤其是圖案化硬遮罩38，中選擇性的氮氧化石夕層4㈣為被氮 化，而使彳于氮化後的選擇性的氮氧化矽層4〇和材料層3〇中的低介 電材料36的触刻速率拉近，因此，在姓刻後可形成如第5圖圓圈標 示的平順輪廓60。 除此之外’本發㈣有提供了三種可避免I化鈦凸起物形成的方 式說月如下.增加触刻用之電漿機台的兩電極之間距、降低触刻 時電聚機台之功率或者在姓刻時通入輸送氣體(cardergas)，如氮 氣、氬氣或氦氣。增加電極之間距和降低钱刻電聚之功率，其目的 在於降低電極之間的t場，t電場降低後，在反應室中的氟離子的 量就會下降’因此就可降低氟離子和鈦金屬層反應。另外，通入輸 送氣體的目的是讓蚀刻時，部分的鈦金屬層表面會反應成含氮化合 物，如氮化鈦，如此，欽金屬層就不會和働速體反應，即可避免 形成氟化鈦凸起物。根據發明人的研究發現，將兩電極的距離維持 在26毫米至33毫米之間，或者是將機台之操作功率調整在⑽瓦至 150瓦之間並配合操作頻率2百萬_、2千7百萬赫兹或6千_ 兹，亦或者是在侧時通人2㈣每分鐘鮮餅(_)的輸送氣 體，皆可有效地避免A化鈦凸起物_成。上述的三種方式可以單 獨使用、相互搭配使用’甚至配合預處理製程，舉例而言，可以在 姓刻前先氮化圖案化硬遮罩，然後在韻刻時,,再配合通入輸送氣體， 可使得避免氟化鈦凸起物形成的效果更佳。 以上所述僅為本發明之較佳實施例，凡依本發明申請專利範圍所 做之均等變化與修飾，皆應屬本發明之涵蓋範圍。 201123295 【圖式簡單說明】 第1圖至第2圖繪示的是習知圖案化硬遮罩之方法。 第3圖至第5晴示的是本發明之形細案的方法。 第6崎示的是圖案化硬遮罩變形之示意圖。 第7圖繪示的是材料層祕職發生碗雜廓之示意圖。 =8圖繪示的是習知技術中材料層經_後發生碗形輪靡之示意 【主要元件符號說明】 10 ^ 10 14、48 18 3〇 待餘刻之材料層 12 硬遮罩 氧化碎層 16、 40、46 氮氧化矽層 氮化矽層 20 圖案化之硬遮罩 34 材料層 32 金屬内連線層 介電層 35 硬遮罩層 J6 .. 38、38, 44 低介電材料層 38 金屬插塞 圖案化硬遮罩 42 鈦金屬層 氮化鈦層 50 預處理 52 56 62 氮化鈦 54 乳化g太凸起物 碳氟高分子聚合物 碗形輪廓 60 平順輪廓 11201123295 VI. Description of the Invention: [Technical Field of the Invention] The present invention is directed to a method of forming a method, particularly a method of avoiding a hard mask from adhering a silver-etched reactant when the shape is fine. [Prior Art] The fabrication of an integrated circuit or a microelectromechanical system utilizes a semiconductor substrate, such as a hard wafer, and repeatedly undergoes hundreds of different methods of thin film deposition, oxidation, lithography, rotting and smashing. . In the lithography and the process, a patterned photoresist is formed on the substrate t film and the pattern of the transfer side photoresist is transferred to the underlying film. However, with the reduction of the inch size, the resolution of the lithography button needs to be improved. The currently used squares are difficult to edit, and the _(4) numerical aperture allows for a resolution of 4 degrees, but it will make the image projected into the photoresist deeper. Version 0 (4) is reduced, resulting in a thinned patterned photoresist layer. Will ride most of the gambling resistance of the photoresist has a lighter than the photoresist material process #, using a hard mask instead of the photoresist, because the hard mask on the board (four) traceability, so use a hard mask as a mask to etch the base hard The hard cover material will not wear out when it is _, but the pattern of __. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a composite material layer <RTI ID=0.0>>>""""" As shown in Fig. 1 , the material layer of the rhyme carving of the 羞 寺 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬 硬Micro 201123295 and rhyme engraving process 'before re-patterning hard surface 12: after =:=!^嚷 not shown), the patterned hard material 2G. '冼 can form a hard solution 2G of the pattern of Figure 2, the phase of the phase is different for each phase and the unevenness is generated at the opening; the pattern of the product cannot be transferred to the paste after the side of the pattern. Content] = 2 raising - lion tears, admire the above questions. The first preferred embodiment of the present invention provides a method for forming a pattern: Γ:: a layer of material that is engraved, and the material layer can be a dielectric layer to be formed into a metal interconnect. The mask, the t_hard mask can be a singular layer or a single-layer structure, and the thief can carry out the process, which can be used to process the process, the oxidation process or the actinic Korean process, and then The treated patterned hard mask acts as a mask to etch the material layer. According to another preferred embodiment of the present invention, any combination of a hard fresh pin, a oxynitride layer, a vaporized titanium layer, and a titanium lining is used. After the generalization process has been processed, the surface of the titanium metal layer is converted into titanium nitride. According to still another preferred embodiment of the invention, the distance between the two electrodes of the machine is between 26 mm and 33 mm. According to the further embodiment of the present invention, the operation at time _ is changed from 5 watts to 15 〇 201123295 watts. According to a further preferred embodiment of the invention, nitrogen is introduced as a transport gas. The invention is characterized in that the surface property of the hardened mask is changed, so that the patterned hard mask does not disadvantageously in the side material layer (the wall (10) w and the surname gas react to produce the object, the fine case The hard mask is deformed and the residual residue accumulates on the patterned hard mask. Another feature of the present invention is that there are several ways to avoid the deformation of the hard mask, which can be used alone or in combination to enhance the effect. Embodiments 3 to 6 illustrate a method of forming a pattern of the present invention. As shown in FIG. 3, first, a material layer 3G is provided, for example, including a dielectric layer % and a low dielectric layer. The material layer 36's material layer 3 is located above a metal interconnect layer %, wherein the metal interconnect 37 is located at the metal interconnect layer 32 t, for example, the metal interconnect 37 The hard mask layer 35 may be sequentially formed by a single inlaid metal wire or gold conductor wire or a conductive element u of other metal plugs. The hard mask layer contains less - gold-containing material, hard cover The cover layer 35 can be made of selective, selective gold 42, titanium layer 44, selective nitrogen The oxygen-cut layer handles the selective milk layer 48 from the bottom-up stack of composite layers on the material layer 3', then the patterned hard mask (4), and then the hard mask (4), and then By removing the silk of the chemical, it is possible to form a hard cover as shown in Fig. 4. It is worthy of note 4 that: the hard-cut oxygen-cut layer, the selective nitrogen emulsification 46, the titanium nitride layer 44 and the selective titanium metal layer 42 are etched through the 201123295 until the exposure selectivity is exposed. The ruthenium oxynitride layer is 4 〇, and the selective ruthenium oxynitride layer 4 〇 is only partially removed, that is, the selective low-dielectric material layer 36 under the nitrous oxide layer 40 is not exposed. It is still shielded by the oxynitride layer 4, so the low dielectric material layer 36 is not adversely affected in the step of removing the photoresist. Further, the material of the hard mask can be used in any combination of the above materials or other materials depending on factors such as stress, anti-reflection ability, adhesion, and side resistance. For example, different hard mask materials may have different stress types such as tensile stress and shrinkage stress, so that the total stress of the hard mask material does not cause excessive stretching or shrinkage on the layer of material to be inscribed below, thus reducing The risk of the layer. According to another preferred embodiment of the present invention, the material layer 30 of the Wei engraved material may also comprise a rotating material, a conductive material or a work function material, etc., and the pattern to be created may be a through hole, a groove, a line or a region. Piece. The titanium metal layer 42 in the patterned hard mask % can be changed into a group, a lanthanum, a rare earth element or a transition metal element according to different process requirements, and the titanium nitride layer 44 can also use other metal nitrides or metal oxides. Instead of nitriding group, oxidizing group, and the like. In addition, the patterned hard mask 38 may further include an organic material such as a photoresist, and the material composition of the patterned hard mask 38 may be other multilayer structures or a single layer. Further, the method of the present invention may be applied. Various methods in semiconductor fabrication require the use of a hard masking process, the embodiments of which are described below for the fabrication of metal interconnects, and others such as gate definition or dual damascene processes. The material of the patterned hard fresh material comprises a photosensitive material f, such as a photo mask, to form a patterned hard mask 38, the steps of which are achieved by a combination of a lithography process, that is, an exposure and development step. And the steps are required after patterning the hard mask %. 201123295 As shown in Figure 5, after the formation of the patterned hard mask %, the next 5 〇 is performed, such as nitriding, and the patterned hard mask is exposed to space = nitriding treatment to form _ hard mask 38, the selective oxynitride layer 4G exposed in the hard cover (4) 'selective titanium metal layer 42, nitride 44, selective nitrogen oxides 46 and selective oxygen The layer 48 is formed at the nitrogen to form a fine bond into the seam, and it is particularly convenient to hide the money. The eyesight is to make the titanium metal layer exposed to the space in the hard material 38 is the titanium metal layer. The surface of the side wall of 42 forms titanium nitride & in addition, the upper surface and the side wall surface of the nitrogen oxynitride are also nitrided at the same time. The nitriding process uses New Zealand, and the preferred condition for the insertion is to operate a fresh 27 million thief or 60 million to 15 seconds of reaction. In the final stage, as shown in the sixth riding, the pre-processed patterned hard mask % is used as a mask, and the button engraving material layer 30' completes the pattern transfer. Since the patterned hard mask %, and the nitride of the surface of the patterned hard mask 38' are consumed during the process, a portion of the hard material 38 is left in Fig. 6. The step of the material layer 3Q can be performed after the graphing of the hard mask warfare processing _ (in_situ bribe, 妓 伽 伽 )). The pretreatment S0 can be changed to an oxidation process according to different process requirements or using an actinic laser process such as ultraviolet light irradiation or other surface characteristics (chemical or physical properties) which can change the patterned hard mask. For example, the critical dimension of the patterned hard mask 38 after the oxidation treatment can be reduced; and the relaxation in the formed hard mask 38 after the ultraviolet light irradiation increases the hardness to A better masking effect is provided in subsequent etching steps. Figure 7 is a schematic diagram showing the deformation of the patterned hard mask, in which the same elements are denoted by the same symbols as 201123295, and in the conventional step of etching the material layer, fluorocarbon is usually used as the engraving gas, for example, tetrafluorination. Carbon, tri-failure, hexafluoride, after the carbon gas compound is ionized, the axis of rotation, which contains _, fluorocarbon free radicals. However, the conventional process does not pre-process the patterned hard mask before the material layer is surnamed. As shown in Fig. 7, when the electric engraving is utilized, the untreated metal layer 42 is shouted. It will react with fluoride ions to form a β彳 product such as a distorted titanium bump 54 adhered to the surface of the titanium metal layer μ, and then the residual residue such as the fluorocarbon polymer 56 is deposited on the patterned hard. The sidewall of the mask 38 causes the patterned hard mask 38 to deform, changing the size of the opening to be defined, thereby seriously affecting the effect of the surname. Different from the prior art, the present invention utilizes pretreatment to convert the surface of the metal layer 42 into titanium nitride, thereby reducing the possibility of the titanium metal layer reacting with the side gas, thereby effectively preventing the gasification of the protrusion. 54. Fig. 8 is a green representation of a conventional material layer _ a schematic representation of a bowl-shaped wheel gallery after engraving. The same elements are denoted by the same reference numerals. In the traditional step, because the _ rate of the patterned hard mask and the material layer are too large, the bowl-shaped wheel will be formed behind the side, and the ridge will be selectively selected by the old patterned hard mask. The nitrogen oxynitride layer 40, the selective titanium metal layer 42, the gasification, the selective nitrogen oxide (10) 46 and the oxidation resistance are still examples, and the selectivity is not The side rate of the ruthenium oxynitride layer is lower than that of the lower dielectric material, so the low dielectric material 36 will be more engraved when it is on the side, and the nitrous oxide layer is less engraved. This in turn causes a bowl-shaped Na's weep as indicated by a circle in Figure 8. As shown in the figure, the patterned hard mask % formed after pre-treatment 5 本 in the month of the month, the quality of the enamel is changed 1 ', so that the patterning hard mask 38, the button engraving rate and the material layer % Pull 201123295 Near, especially the patterned hard mask 38, the selective NOx layer 4 (4) is nitrided, and the selective yttria layer 4 材料 and material layer 3彳 after nitriding The etch rate of the low dielectric material 36 is drawn closer, so that a smooth contour 60 as indicated by the circle in Fig. 5 can be formed after the last name. In addition, 'this hair (four) has provided three ways to avoid the formation of titanium protrusions. The month is as follows. Increasing the distance between the two electrodes of the plasma machine for the engraving, and reducing the electro-convergence machine when inducing The power or the cardergas, such as nitrogen, argon or helium, is introduced at the time of the last name. Increasing the distance between the electrodes and reducing the power of the electricity, the purpose is to reduce the t-field between the electrodes. After the electric field is reduced, the amount of fluoride ions in the reaction chamber will decrease, thus reducing the fluoride ion and titanium. The metal layer reacts. In addition, the purpose of introducing the gas is to allow some of the surface of the titanium metal layer to react into a nitrogen-containing compound, such as titanium nitride, so that the metal layer does not react with the idle body, thereby avoiding the formation of fluorine. Titanium protrusions. According to the study by the inventors, the distance between the two electrodes is maintained between 26 mm and 33 mm, or the operating power of the machine is adjusted between (10) watts and 150 watts and the operating frequency is 2 million _, 2,000. 7 million Hz or 6 kilograms, or the side of the 2 (four) per minute fresh cake (_) of the transport gas, can effectively avoid the titanium carbide protrusions. The above three methods can be used alone or in combination with each other's even with a pre-treatment process. For example, the patterned hard mask can be nitrided before the last name, and then the gas is conveyed when the rhyme is engraved. The effect of avoiding the formation of titanium fluoride protrusions can be made better. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should fall within the scope of the present invention. 201123295 [Simple description of the drawings] Figs. 1 to 2 illustrate a conventional method of patterning a hard mask. 3 to 5 clearly show the method of the present invention. The sixth is a schematic diagram of the deformation of the patterned hard mask. Figure 7 shows a schematic diagram of a bowl of miscellaneous profiles in the material layer. The figure of Fig. 8 shows the schematic representation of the bowl-shaped rim after the material layer passes through the conventional technique. [Main component symbol description] 10 ^ 10 14, 48 18 3 The material layer to be etched 12 Hard mask oxidized smash Layer 16, 40, 46 yttria layer tantalum nitride layer 20 patterned hard mask 34 material layer 32 metal interconnect layer dielectric layer 35 hard mask layer J6 .. 38, 38, 44 low dielectric material Layer 38 Metal plug patterned hard mask 42 Titanium metal layer Titanium nitride layer 50 Pretreatment 52 56 62 Titanium nitride 54 Emulsified g too convex fluorocarbon polymer bowl shape contour 60 Smooth contour 11