TWM520723U - EUV photomask protective film structure - Google Patents

Description

EUV光罩保護膜結構EUV mask protective film structure

本創作是有關一種EUV光罩保護膜結構，特別是一種能夠於一石墨稀層兩個表面分別沉積形成出有一氮化矽層，該氮化矽層能夠用以夾持該石墨稀層，並用以保護該石墨稀層，除增加該石墨稀層的結構強度外，並可藉由石墨稀材料的特性達到高光穿透率之目的，且石墨稀為無機材料，可減少污染物質的產生。The present invention relates to an EUV mask protective film structure, in particular, capable of depositing a tantalum nitride layer on two surfaces of a graphite thin layer, which can be used to sandwich the graphite thin layer and use In order to protect the graphite thin layer, in addition to increasing the structural strength of the graphite thin layer, the high light transmittance can be achieved by the characteristics of the graphite thin material, and the graphite is an inorganic material, which can reduce the generation of pollutants.

半導體元件的電路圖案是通過使用光罩及曝光技術的微影製程將電路圖案轉印至矽晶圓的表面。光罩的缺陷會造成矽晶圓表面的電路圖案扭曲或變形，已知造成光罩缺陷的原因之一在於光罩的表面受到污染微粒（contamination particles）的污染，使得矽晶圓表面的電路圖案在有污染微粒之處產生了扭曲或變形；The circuit pattern of the semiconductor element is a transfer of the circuit pattern to the surface of the germanium wafer by a lithography process using a photomask and an exposure technique. The defect of the mask may cause distortion or deformation of the circuit pattern on the surface of the wafer. One of the reasons for the known defect of the mask is that the surface of the mask is contaminated by contamination particles, so that the circuit pattern on the surface of the wafer is Distortion or deformation in the presence of contaminated particles;

為了維持光罩在使用期間的品質，已知的一種方法是在光罩的表面設置一種光罩保護薄膜組件（pellicle），用以防止污染微粒沈積直接接觸到光罩表面；光罩保護薄膜組件的構造基本上包含透明的一保護薄膜（film）和一框架，保護薄膜提供阻隔外界污染的實體屏障，用於防止來自環境、氣體逸出（outgassing）或其他原因而產生的污染微粒污染光罩的表面。In order to maintain the quality of the reticle during use, a known method is to provide a reticle protective film assembly on the surface of the reticle to prevent the deposition of contaminated particles from directly contacting the reticle surface; the reticle protective film assembly The structure basically comprises a transparent protective film and a frame, and the protective film provides a physical barrier that blocks external pollution, and is used to prevent pollution particles from environmental, gas outgassing or other causes from contaminating the mask. s surface.

依據電路圖案的寬度，曝光技術使用的光源的波長也有不同，針對不同波長的曝光光源，保護薄膜必需具有足夠的穿透率（Transmission）以確保微影製程的良率，保護薄膜的穿透率取決於保護薄膜的厚度、抗反射塗佈的類型、保護薄膜的材質對光的吸收度及晶圓曝光機或步進機所使用的光源的波長，硝化纖維素（nitrocellulose）是最初被採用的薄膜材質，而且這類保護薄膜是使用於g-line（436 nm）或i-line（365 nm），另外氟化高分子用於KrF（248nm）或ArF（193nm）的晶圓曝光機或寬頻投射晶圓步進機。隨著電路圖案的細微化，使用波長只有13.5奈米（nanometer, nm）的極紫外光（EUV）作為曝光光源的微影製程開始受到重視並積極地發展相關的技術，然而前述用於製造保護薄膜的硝化纖維素材質會吸收波長小於350nm的光源，而氟化高分子會吸收波長小於190nm，因此不能使用在光源波長低於350nm或190nm的微影製程。Depending on the width of the circuit pattern, the wavelength of the light source used in the exposure technique is also different. For different wavelengths of exposure light, the protective film must have sufficient transmission to ensure the yield of the lithography process and protect the transmittance of the film. Depending on the thickness of the protective film, the type of anti-reflective coating, the light absorption of the material of the protective film, and the wavelength of the light source used in the wafer exposure machine or stepper, nitrocellulose was originally adopted. Film material, and this kind of protective film is used for g-line (436 nm) or i-line (365 nm), and fluorinated polymer is used for KrF (248nm) or ArF (193nm) wafer exposure machine or broadband Projecting a wafer stepper. With the miniaturization of circuit patterns, the lithography process using ultra-ultraviolet light (EUV) with a wavelength of only 13.5 nanometers (nm) as an exposure source has begun to receive attention and actively develop related technologies, but the foregoing is used for manufacturing protection. The nitrocellulose material of the film absorbs a light source having a wavelength of less than 350 nm, and the fluorinated polymer absorbs a wavelength of less than 190 nm, so that a lithography process in which the wavelength of the light source is lower than 350 nm or 190 nm cannot be used.

因為矽結晶膜是用於EUV的光，故光吸收係數相對比較低，特別是多結晶矽膜，跟非晶質矽膜或單結晶矽膜比較起來吸收係數更低，故能輕易滿足EUV用防護薄膜所需要的透光率；特別是上述採用矽結晶膜製作用於EUV的防護薄膜，在矽結晶膜成形的技術上仍存在著矽結晶膜成形不易的問題，在已公告的美國專利6,623,893，其中提出了一種以矽材質製作的保護薄膜，該保護薄膜係可採用化學汽相沉積（chemical vapor deposition, CVD）技術形成於同樣用矽材質（如二氧化矽）製成的一屏柵層（barrier layer），再利用刻蝕（etching）製程移除屏柵層的方式而令保護薄膜的中央部份顯露出來，但是這種製程較為複雜。Since the ruthenium crystal film is light for EUV, the light absorption coefficient is relatively low, especially the polycrystalline ruthenium film, which has a lower absorption coefficient than the amorphous ruthenium film or the single crystal ruthenium film, so that it can easily satisfy the EUV. The light transmittance required for the protective film; in particular, the above-mentioned protective film for EUV using a ruthenium crystal film, there is still a problem that the ruthenium crystal film is not easily formed in the technique of ruthenium crystal film formation, and the published US Patent 6,623,893 A protective film made of tantalum material is proposed, which is formed by a chemical vapor deposition (CVD) technique on a gate layer made of a tantalum material such as hafnium oxide. The barrier layer is formed by removing the screen layer by an etching process, but the central portion of the protective film is exposed, but the process is complicated.

另外在已公開的中國專利CN 101414118 A揭露了一種由單結晶矽膜製作而成光罩保護薄膜及其製造方法，該方法係透過將SOI基板薄膜化而製成，具體而言是在薄膜化的SOI基板的一主要表面形成單結晶矽的保護膜，再於後續的製程中同樣地以刻蝕的技術移除SOI基板而令單結晶矽的中央部份顯露成為保護膜。Further, in the disclosed Chinese patent CN 101414118 A, a reticle protective film made of a single crystal ruthenium film and a method for producing the same are disclosed, which are produced by thinning an SOI substrate, specifically, thinning. A main surface of the SOI substrate forms a protective film of a single crystal germanium, and in the subsequent process, the SOI substrate is removed by an etching technique to expose the central portion of the single crystal germanium as a protective film.

在已公開的台灣專利「EUV用防塵薄膜組件」(公開號201415157)，其中提出了一種能夠減輕入射EUV光的減少，同時具有高強度的EUV用防塵薄膜組件。其中透過一種具有用網格形狀(例如蜂窩結構)的輔助結構加固的EUV透過膜（為一種矽晶膜）的EUV用防塵薄膜組件，但是該輔助結構與矽晶膜如果沒有牢固地貼緊，在曝光的過程中會造成輔助結構與矽晶膜的分離，進而造成矽晶膜的破損。In the disclosed Taiwan patent "Pneumatic film assembly for EUV" (Publication No. 201415157), a dust-proof film assembly for EUV which can reduce the reduction of incident EUV light and has high strength is proposed. Wherein the EUV pellicle is assembled through an EUV permeable film (which is a twin film) reinforced with an auxiliary structure of a mesh shape (for example, a honeycomb structure), but the auxiliary structure and the twin film are not firmly adhered thereto. During the exposure process, the separation of the auxiliary structure from the twin film is caused, which causes damage to the twin film.

不論使用於何種曝光光源的光罩保護薄膜組件，其中保護薄膜的材質必須具備適當的均勻度、機械強度、穿透度、及潔淨度來承受不斷將光罩圖案曝光至晶圓上的微影製程，以及克服儲存和運送過程污染或是損壞光罩保護薄膜的問題；另外在已核准公告的台灣發明專利TW I398723「防護薄膜組件及其製造方法」，提出了一種以矽單結晶膜作為防護薄膜的防護薄膜組件，其中包含在防護薄膜的至少一面形成一無機保護膜，但由於該無機保護膜容易會因為移動時產生破裂，因此如何避免此一情況發生，將是本發明之重點。Regardless of the exposure of the illuminant protection film assembly, the material of the protective film must have appropriate uniformity, mechanical strength, penetration, and cleanliness to withstand the continual exposure of the reticle pattern to the wafer. Shadow processing, and overcoming the problem of contamination during storage and transportation or damage to the reticle protective film; in addition, the approved invention patent TW I398723 "Protective film assembly and its manufacturing method" has proposed a single crystal film. The pellicle film of the pellicle film comprises an inorganic protective film formed on at least one side of the pellicle film, but since the inorganic protective film is liable to be broken due to movement, how to avoid this situation will be the focus of the present invention.

因此，若能夠於一無機保護膜（石墨稀層）兩個表面分別沉積形成出有一氮化矽層，該氮化矽層能夠用以夾持該石墨稀層、並用以保護該石墨稀層、以增加該石墨稀層的結構強度，因此能夠避免移動時該石墨稀層產生破裂，故本發明應為一最佳解決方案。Therefore, if a tantalum nitride layer can be separately deposited on both surfaces of an inorganic protective film (graphite thin layer), the tantalum nitride layer can be used to sandwich the graphite thin layer and protect the graphite thin layer, In order to increase the structural strength of the graphite thin layer, it is possible to avoid cracking of the graphite thin layer during the movement, so the present invention should be an optimal solution.

本創作係一種EUV光罩保護膜結構，包括：一框架，係具有二個結合面； 一多層保護薄膜，係具有一石墨稀層，該石墨稀層的頂端表面結合有一第一氮化矽層，而底端表面結合有一第二氮化矽層，形成一三層結構；係藉由無機膠體將多層保護薄膜黏固於該框架的的其中一結合面，以將框架之其中一表面遮蔽。The present invention relates to an EUV mask protective film structure, comprising: a frame having two bonding faces; a multilayer protective film having a graphite thin layer, the top surface of the graphite thin layer being bonded with a first tantalum nitride a layer, wherein the bottom end surface is combined with a second layer of tantalum nitride to form a three-layer structure; the multilayer protective film is adhered to one of the joint surfaces of the frame by an inorganic colloid to shield one surface of the frame .

於一較佳實施例中，其中該第一氮化矽層及第二氮化矽層係以化學氣相沉積法沉積於石墨稀層的表面。In a preferred embodiment, the first tantalum nitride layer and the second tantalum nitride layer are deposited on the surface of the graphite thin layer by chemical vapor deposition.

於一較佳實施例中，其中該多層保護薄膜的石墨稀層厚度為8nm，該第一氮化矽層厚度為5nm，該第二氮化矽層厚度為5nm，在波長13.5nm的極紫外光照射下，其光穿透率為90%。In a preferred embodiment, wherein the multilayer protective film has a graphite thin layer thickness of 8 nm, the first tantalum nitride layer has a thickness of 5 nm, the second tantalum nitride layer has a thickness of 5 nm, and an extremely ultraviolet wavelength of 13.5 nm. Under light irradiation, the light transmittance is 90%.

如於一較佳實施例中，其中該多層保護薄膜的石墨稀層厚度為25nm，該第一氮化矽層厚度為5nm，該第二氮化矽層厚度為5nm，在波長13.5nm的極紫外光照射下，其光穿透率為80%。In a preferred embodiment, wherein the multilayer protective film has a graphite thin layer thickness of 25 nm, the first tantalum nitride layer has a thickness of 5 nm, and the second tantalum nitride layer has a thickness of 5 nm at a wavelength of 13.5 nm. Under ultraviolet light, the light transmittance is 80%.

於一較佳實施例中，其中該第一氮化矽層及第二氮化矽層可以第一釕金屬及第二釕金屬取代。In a preferred embodiment, the first tantalum nitride layer and the second tantalum nitride layer may be replaced by a first base metal and a second base metal.

於一較佳實施例中，其中該第一釕金屬層及一第二釕金屬層的厚度皆為5nm。In a preferred embodiment, the first base metal layer and the second base metal layer each have a thickness of 5 nm.

有關於本創作其他技術內容、特點與功效，在以下配合參考圖式之較佳實施例的詳細說明中，將可清楚的呈現。Other technical contents, features, and effects of the present invention will be apparent from the following detailed description of the preferred embodiments.

請參閱第1圖，為本創作EUV光罩保護膜結構之剖面結構示意圖，主要包括一框架1及一多層保護薄膜2，其中該框架1係具有一第一結合面11及一第二結合面12，該多層保護薄膜2具有一石墨稀層（Graphene）21，該石墨稀層21的頂面上結合有一第一氮化矽層22，而石墨稀層21的底面結合有一第二氮化矽層23，使石墨稀層21受到第一氮化矽層22及第二氮化矽層23的夾持，形成一類似三明治結構，以增加石墨稀層21的結構強度，避免石墨稀層21在搬移過程發生破碎損毀情形；係將該第二氮化矽層23藉由無機膠體3黏固於框架1的第一結合面11，以將框架1的其中一開放表面遮蔽。Please refer to FIG. 1 , which is a cross-sectional structural view of a protective EUV protective film structure, which mainly includes a frame 1 and a multilayer protective film 2 , wherein the frame 1 has a first bonding surface 11 and a second combination. The multilayer protective film 2 has a graphite thin layer 21 having a first tantalum nitride layer 22 bonded to the top surface of the graphite thin layer 21 and a second nitride bonded to the bottom surface of the graphite thin layer 21. The ruthenium layer 23 is such that the graphite thin layer 21 is sandwiched by the first tantalum nitride layer 22 and the second tantalum nitride layer 23 to form a sandwich-like structure to increase the structural strength of the graphite thin layer 21 and avoid the graphite thin layer 21 The crushing damage occurs during the moving process; the second tantalum nitride layer 23 is adhered to the first bonding surface 11 of the frame 1 by the inorganic colloid 3 to shield one of the open surfaces of the frame 1.

請參閱第2圖及第3圖所示，係為本創作EUV光罩保護膜結構之與一光罩結合示意圖，係將該框架1的第二結合面12以無機膠體4結合於一光罩5的頂面周圍，以將光罩5之曝光區域51遮蔽，該多層保護薄膜2藉由框架1的支撐而不與光罩5的曝光區域51接觸，並且在框架1及多層保護膜2和光罩10之間形成一內腔52，該框架1的其中一側壁13具有一通氣孔14用以令內腔52的氣壓和環境氣壓保持平衡，通氣孔14設有一過濾膜6用以防止污染物質或微粒侵入內腔52。Please refer to FIG. 2 and FIG. 3 , which is a schematic diagram of the combination of the structure of the EUV mask protective film and the reticle, and the second bonding surface 12 of the frame 1 is bonded to the reticle by the inorganic colloid 4 . Around the top surface of the cover 5, the exposed area 51 of the reticle 5 is shielded by the support of the frame 1 without coming into contact with the exposed area 51 of the reticle 5, and in the frame 1 and the multilayer protective film 2 and light. An inner cavity 52 is formed between the cover 10. One of the side walls 13 of the frame 1 has a vent hole 14 for balancing the air pressure of the inner cavity 52 with the ambient air pressure. The vent hole 14 is provided with a filter film 6 for preventing pollutants or The particles invade the lumen 52.

請參閱第4圖所示，係本創作之實施示意圖，當在使用波長13.5nm的極紫外光7的照射下，該石墨稀層21的厚度可為8nm，該第一氮化矽層22之厚度為5nm，而該第二氮化矽層23之厚度為5nm，該多層保護薄膜2的光穿透率係為90%。Referring to FIG. 4, it is a schematic diagram of the implementation of the present invention. When irradiated with extreme ultraviolet light 7 having a wavelength of 13.5 nm, the thickness of the graphite thin layer 21 may be 8 nm, and the first tantalum nitride layer 22 is The thickness is 5 nm, and the thickness of the second tantalum nitride layer 23 is 5 nm, and the light transmittance of the multilayer protective film 2 is 90%.

若該石墨稀層21的厚度為25nm，該第一氮化矽層22之厚度為5nm，而該第二氮化矽層23之厚度為5nm，在使用波長13.5nm的極紫外光7照射下，該多層保護薄膜2的光穿透率係為80%。If the thickness of the graphite thin layer 21 is 25 nm, the thickness of the first tantalum nitride layer 22 is 5 nm, and the thickness of the second tantalum nitride layer 23 is 5 nm, which is irradiated with extreme ultraviolet light 7 having a wavelength of 13.5 nm. The multilayer protective film 2 has a light transmittance of 80%.

另外，上述之第一氮化矽層22及第二氮化矽層23可以第一釕金屬及第二釕金屬。In addition, the first tantalum nitride layer 22 and the second tantalum nitride layer 23 may be a first base metal and a second base metal.

本創作所提供之EUV光罩保護膜結構，與其他習用技術相互比較時，其優點如下： 1.      本創作能夠於一石墨稀層21兩個表面分別沉積形成出有第一氮化矽層22及第二氮化矽層23，該第一氮化矽層22及該第二氮化矽層23能夠用以夾持該石墨稀層21、並用以保護該石墨稀層21、以增加該石墨稀層21的結構強度，因此能夠避免移動時該石墨稀層21產生破裂。 2.      本創作以石墨稀層21作為光罩保護膜的材料，因石墨稀層21為無機材料及具有高透明度，因此具有良好的光穿透率及不會產生污染物質，以延長光罩的使用壽命。 本創作已透過上述之實施例揭露如上，然其並非用以限定本創作，任何熟悉此一技術領域具有通常知識者，在瞭解本創作前述的技術特徵及實施例，並在不脫離本創作之精神和範圍內，當可作些許之更動與潤飾，因此本創作之專利保護範圍須視本說明書所附之請求項所界定者為準。The advantages of the EUV mask protective film structure provided by the present invention, when compared with other conventional techniques, are as follows: 1. The present invention can deposit a first tantalum nitride layer 22 on two surfaces of a graphite thin layer 21, respectively. And the second tantalum nitride layer 23, the first tantalum nitride layer 22 and the second tantalum nitride layer 23 can be used to sandwich the graphite thin layer 21 and to protect the graphite thin layer 21 to increase the graphite The structural strength of the thin layer 21 can thus avoid cracking of the graphite thin layer 21 when moving. 2. This creation uses the graphite thin layer 21 as the material of the mask protective film. Since the graphite thin layer 21 is an inorganic material and has high transparency, it has good light transmittance and does not generate pollutants to extend the mask. Service life. The present invention has been disclosed above in the above embodiments, but it is not intended to limit the present invention. Anyone skilled in the art having ordinary knowledge will understand the foregoing technical features and embodiments of the present invention without departing from the present invention. In the spirit and scope, the scope of patent protection of this creation shall be subject to the definition of the requirements attached to this manual.

1‧‧‧框架
11‧‧‧第一結合面
12‧‧‧第二結合面
13‧‧‧壁面
14‧‧‧通氣孔
2‧‧‧多層保護薄膜
21‧‧‧石墨稀層
22‧‧‧第一氮化矽層
23‧‧‧第二氮化矽層
3‧‧‧無機膠體
4‧‧‧無機膠體
5‧‧‧光罩
51‧‧‧曝光區域
52‧‧‧內腔
6‧‧‧過濾膜
7‧‧‧極紫外光1‧‧‧Frame
11‧‧‧ first joint
12‧‧‧Second junction
13‧‧‧ wall
14‧‧‧Ventinel
2‧‧‧Multilayer protective film
21‧‧‧Thin graphite layer
22‧‧‧First tantalum layer
23‧‧‧Second tantalum layer
3‧‧‧Inorganic colloid
4‧‧‧Inorganic colloid
5‧‧‧Photomask
51‧‧‧Exposure area
52‧‧‧ lumen
6‧‧‧Filter membrane
7‧‧‧ Extreme ultraviolet light

[第1圖]係本創作EUV光罩保護膜結構之剖面結構示意圖。        [第2圖]係本創作EUV光罩保護膜結構之與一光罩結合示意圖。        [第3圖]係第2圖的剖面示意圖。        [第4圖]係本創作EUV光罩保護膜結構之實施示意圖。[Fig. 1] is a schematic cross-sectional structure of the EUV mask protective film structure. [Fig. 2] is a schematic diagram of the structure of the EUV mask protective film and the photomask. [Fig. 3] is a schematic cross-sectional view of Fig. 2. [Fig. 4] is a schematic diagram of the implementation of the EUV mask protective film structure.

1‧‧‧框架 1‧‧‧Frame

11‧‧‧第一結合面 11‧‧‧ first joint

12‧‧‧第二結合面 12‧‧‧Second junction

13‧‧‧壁面 13‧‧‧ wall

14‧‧‧通氣孔 14‧‧‧Ventinel

2‧‧‧多層保護薄膜 2‧‧‧Multilayer protective film

21‧‧‧石墨稀層 21‧‧‧Thin graphite layer

22‧‧‧第一氮化矽層 22‧‧‧First tantalum layer

23‧‧‧第二氮化矽層 23‧‧‧Second tantalum layer

Claims (6)

一種EUV光罩保護膜結構，包括： 一框架，係具有二個結合面； 一多層保護薄膜，係具有一石墨稀層，該石墨稀層的頂端表面結合有一第一氮化矽層，而底端表面結合有一第二氮化矽層，形成一三層結構；        係藉由無機膠體將多層保護薄膜黏固於該框架的的其中一結合面，以將框架之其中一表面遮蔽。An EUV reticle protective film structure comprising: a frame having two bonding faces; a multilayer protective film having a graphite thin layer, the top surface of the graphite thin layer being bonded with a first tantalum nitride layer, and The bottom end surface is combined with a second tantalum nitride layer to form a three-layer structure; the multilayer protective film is adhered to one of the bonding surfaces of the frame by an inorganic colloid to shield one surface of the frame. 如請求項1所述之EUV光罩保護膜結構，其中該第一氮化矽層及第二氮化矽層係以化學氣相沉積法沉積於石墨稀層的表面。The EUV mask protective film structure according to claim 1, wherein the first tantalum nitride layer and the second tantalum nitride layer are deposited on the surface of the graphite thin layer by chemical vapor deposition. 如請求項1所述之EUV光罩保護膜結構，其中該多層保護薄膜的石墨稀層厚度為8nm，該第一氮化矽層厚度為5nm，該第二氮化矽層厚度為5nm，在波長13.5nm的極紫外光照射下，其光穿透率為90%。The EUV mask protective film structure according to claim 1, wherein the multilayer protective film has a graphite thin layer thickness of 8 nm, the first tantalum nitride layer has a thickness of 5 nm, and the second tantalum nitride layer has a thickness of 5 nm. The light transmittance was 90% under the irradiation of extreme ultraviolet light having a wavelength of 13.5 nm. 如請求項1所述之EUV光罩保護膜結構，其中該多層保護薄膜的石墨稀層厚度為25nm，該第一氮化矽層厚度為5nm，該第二氮化矽層厚度為5nm，在波長13.5nm的極紫外光照射下，其光穿透率為80%。The EUV mask protective film structure according to claim 1, wherein the multilayer protective film has a graphite thin layer thickness of 25 nm, the first tantalum nitride layer has a thickness of 5 nm, and the second tantalum nitride layer has a thickness of 5 nm. The light transmittance was 80% under the irradiation of extreme ultraviolet light having a wavelength of 13.5 nm. 如請求項1所述之EUV光罩保護膜結構，其中該第一氮化矽層及第二氮化矽層可以第一釕金屬及第二釕金屬取代。The EUV mask protective film structure of claim 1, wherein the first tantalum nitride layer and the second tantalum nitride layer are replaced by a first base metal and a second base metal. 如請求項5所述之EUV光罩保護膜結構，其中該第一釕金屬層及一第二釕金屬層的厚度皆為5nm。The EUV reticle protective film structure of claim 5, wherein the first bismuth metal layer and the second bismuth metal layer each have a thickness of 5 nm.