201113843 六、發明說明： 【發明所屬之技術領域】 法’尤指一種軟性顯 本發明係關於一種軟性顯示元件之製作方 示元件金屬基板之製作方法。 【先前技術】 隨著顯示技術與資訊產品的蓬勃發展，顯示器已從傳統的陰極 射線管㈣hoderaytube，CRT)進入平面顯示器(flatpanddis㈣， #卿)時代。而軟性顯示器(祕le display)更因較習知剛性玻璃面 板平面顯不H具有更㈣、可撓曲、耐衝擊而具安全性，且不受 場合、空間限制等特性，鐶然成為下世代顯示器發展的新趨勢。又 軟性薄職Baa_hin film transistGf，以下祕為基板是 軟性顯不H的f要元件之-，其基板材料的選擇觸發更是軟性 顯不器發展上最重要的議題。目前軟性基板材料上的選擇有塑膠 基板(plastic substrate)、超薄(thin giass)玻璃基板 金屬. ㈣al㈣，其中塑膠基板雖可實現輕薄、耐衝擊、低 鲁但塑膠基板具有不耐高溫製程、阻水氣與阻氧氣能力不足與熱膨 脹係數較大4問題。超薄玻璃基板雖然具有耐高溫、安定性高等 特性，但其仍具有薄化玻璃基板時難以克服的高成本問題，以及 較不耐衝擊等缺點。 金屬軟板的耐南溫性質遠高於塑膠與玻璃，其熱膨脹係數較 低、阻水氣與阻氧氣能力佳、且具有低靜電效應、製程上的耐化 學腐蝕性及較佳安定性、低成本等特點，使得金屬軟板成為較具 潛力的軟性TFT基板材料。然而’以金屬軟板作為軟性TFr基板 最大的挑戰’在於金屬表面粗糙度的克服。請參閱第1圖，第1 201113843 圖係為一習知金屬軟性TFT基板之剖面示意圖。如第丄圖所示， 金屬軟性TFT基板1〇〇包含一金屬基底1〇2，金屬基底1〇2的表 面平坦度非常差’其均方根(root mean sqUare ’ RMS)值大於1000 埃(angstrom)，因此其上的元件1〇6彷彿製作在高高低低的山峰 上，不易製作成功；此外金屬基底102表面上的尖點1〇4甚至會 影響其上元件的電特性。為了避免在此高低落差過大的表面上製 作元件，業者常有利用化學機械研磨法(chemical mechanical polishing ’ CMP)、電化學拋光法(eiectr〇 chemical p〇lishing，ECp)、 • 鏡片拋光技術(suPer mirr〇r technique)、以及於金屬基底1〇2表面形 成一層如第1圖所示的緩衝層108等方法降低表面粗糙度。其中 形成緩衝層108的方法除具有可降低金屬基底1〇2的粗糙度的用 途外，更可作為金屬基底1〇2與其上元件log的絕緣層，並用來 避免金屬基底102上的微粒(particie) no污染元件，因此最常 使用。 值得注意的是，形成緩衝層108此方法仍有幾個缺點：為了確 保緩衝層108可以覆蓋所有的尖點1〇4與缺陷而降低金屬基底1〇2 • 的粗糙度，習知的緩衝層108會做的很厚，其厚度介於i〜5微米 (micrometer ’ /zm) ’大大地增加了製程時間與成本、降低軟性顯 示器的可撓性。更重要的是，一般緩衝層1〇8包含無機材料如氧 化矽等，當氧化矽層厚度增加時，缓衝層1〇8更產生了應力的問 題’進而造成裂缝(crack)，影響了緩衝層1〇8所欲提供的上述功能。 因此，如何能成功地提供具有潛力的金屬軟性Μ基板，且 能解決金屬軟板作為軟性TFT基板所面臨的表面平坦度缺點實 為軟性TFT基板材料的開發中一重要的課題。 201113843 【發明内容】 有鑑於此’本發明之一目的係提供金屬TFT基板之製作方 法，且該製作方法係可克服金屬軟板表面祕度的缺點。 本發明揭露—錄性顯示器元件之製作綠，其包含以下步 驟.k供一承載基底，1卜报#古 开η$成有—犧牲層。接下來於犧牲層上 層’再於緩衝層上形成主動元件。最後對承載 基底進仃㈢射處理，以分離金顧與承載基底。201113843 VI. Description of the invention: [Technical field to which the invention pertains] The invention is particularly a soft invention. The invention relates to a method for fabricating a metal substrate for a flexible display element. [Prior Art] With the booming display technology and information products, displays have entered the era of flat panel displays (flatpanddis(4), #卿) from traditional cathode ray tubes (four) hoderaytubes, CRTs. The soft display is more suitable than the conventional rigid glass panel. It has more (4), flexibility, impact resistance and safety, and is not subject to occasions and space constraints. A new trend in display development. The soft-skinned Baa_hin film transistGf, the following secret is that the substrate is a soft component that is not H-, and the selection of the substrate material is the most important issue in the development of the soft device. At present, the selection of flexible substrate materials includes plastic substrate and thin giass glass substrate metal. (4) al (4), wherein the plastic substrate can be light, thin, impact resistant, and low-rug, but the plastic substrate has high temperature resistance and resistance. The problem of insufficient water vapor and oxygen barrier capacity and a large thermal expansion coefficient are four. Although the ultra-thin glass substrate has characteristics such as high temperature resistance and high stability, it still has a high cost problem that is difficult to overcome when the glass substrate is thinned, and is less resistant to impact. The south temperature resistance of metal flexible board is much higher than that of plastic and glass. It has low thermal expansion coefficient, good water blocking gas and oxygen barrier ability, low electrostatic effect, chemical resistance in process and better stability and low. The characteristics of cost and other make metal soft board become a potential soft TFT substrate material. However, the biggest challenge in using metal flexible sheets as soft TFr substrates is the overcoming of metal surface roughness. Please refer to FIG. 1 , and the first 201113843 diagram is a schematic cross-sectional view of a conventional metal flexible TFT substrate. As shown in the figure, the metal flexible TFT substrate 1A includes a metal substrate 1〇2, and the surface roughness of the metal substrate 1〇2 is very poor, and its root mean sqUare 'RMS value is greater than 1000 Å ( Angstrom), therefore, the component 1〇6 on it seems to be made on high and low peaks, which is not easy to make successfully; in addition, the sharp point 1〇4 on the surface of the metal substrate 102 may even affect the electrical characteristics of the components thereon. In order to avoid fabricating components on such a surface with excessively high and low drops, chemical mechanical polishing (CMP), electrochemical polishing (ECp), and lens polishing (suPer) are often used. The surface roughness is reduced by a method of forming a buffer layer 108 as shown in FIG. 1 on the surface of the metal substrate 1〇2. The method for forming the buffer layer 108 can be used as an insulating layer for the metal substrate 1〇2 and the upper element log, in addition to the use for reducing the roughness of the metal substrate 1〇2, and is used to avoid particles on the metal substrate 102 (particie). ) no contaminated components, so they are most commonly used. It is worth noting that the method of forming the buffer layer 108 still has several disadvantages: in order to ensure that the buffer layer 108 can cover all the sharp points 1〇4 and defects and reduce the roughness of the metal substrate 1〇2, the conventional buffer layer 108 will be very thick, its thickness between i ~ 5 microns (micrometer ' / zm) ' greatly increases the processing time and cost, reducing the flexibility of the flexible display. More importantly, the general buffer layer 1 〇 8 contains inorganic materials such as yttrium oxide, etc., when the thickness of the yttrium oxide layer is increased, the buffer layer 1 〇 8 has a problem of stress, which in turn causes cracks, which affects the buffer. Layer 1〇8 is intended to provide the above functions. Therefore, how to successfully provide a metal soft ruthenium substrate with potential and to solve the surface flatness disadvantage of the metal soft plate as a soft TFT substrate is an important issue in the development of a soft TFT substrate material. SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a method for fabricating a metal TFT substrate, which is capable of overcoming the shortcomings of the surface roughness of the metal flexible board. The invention discloses a green production of a recording display element, which comprises the following steps: k for a carrier substrate, and a sacrificial layer. Next, an active element is formed on the upper layer of the sacrificial layer and then on the buffer layer. Finally, the substrate is loaded into the substrate (three) to separate the gold and the carrier substrate.
月所提供之製作方法’係藉由承載基底提供剛性穩定的 使得主動树得以良好的製作於金屬層與緩衝層上； a…射處理使具有主動元件的金朗與緩衝層得以與承載基 將承縣辅換成軟㈣金屬基底，最終獲得金屬軟性 TFT基板。 【實施方式】 π參閱第2圖至第8圖’其為本發明軟性顯示器元件製作方 έτ之縫:實⑯例。如第2圖所示，本發明首先提供—承載基底 • ’其定義有-第一表面2〇2與一相對之第二表面2〇4。承載基 底200為透光性基底，其可包含玻璃、石英或藍寶石等透光性 材料隨後係於承載基底2〇〇之第一表面202形成一犧牲層21〇， 犧=層210之厚度係小於5〇〇埃。在本較佳實施例中犧牲層21〇 人藉由化予乳相沈積(chemical vapor deposition，以下簡稱為 c，製程形成於第—表面2〇2上，且包含非晶树料。值得注意 的疋在CVD製程中，亦可藉由石夕曱烧⑽挪，5脇)與氮的加入 一調正，增加犧牲層21〇的氫含量。另外，更可在CVD製程之後， 對犧牲層21G進行—氫離子佈植製程或氫離子電漿處理，用以增 201113843 加犧牲層210之氫含量。 請參閱第3圖。接下來於犧牲層21〇上形成一金屬層22〇 :於 此實知例中，金屬層220係包含不鏽鋼(stainiess steei)，其可藉由 濺鍍(sputter)或銀膠塗佈(silver paste c〇ating)等方式形成犧牲層 210上。值得注意的是，當金屬層22〇係藉由濺鍍或銀膠塗佈等方 式形成於犧牲層210上時’其表面平坦度將大為改善。金屬層22〇 之厚度係可小於2 因此本實施例所提供之軟性顯示器元件 更可為一具有超薄金屬基板之軟性顯示器元件。 “請參閱第4圖。接下來於金屬層22〇上形成一緩衝層23〇，緩 衝曰230係用以平坦化金屬層22〇之表面，以及避免金屬層 了後、中形成的元件產生的電容偶合效應，因此緩衝層㈣ 係可包含絕緣之有機材料或無機材料如氧切、氮化料，以提 供金屬層220與元件間的電性隔離。值得注意的是，由於緩衝層 =0下方的金屬層22G之表面平坦度已大為改善，因此緩衝層咖 …須為配合金屬層22〇之平坦度而增加本身的厚度，即可達到平 =化目的。當緩衝層230包含有機材料時，其厚度可為數微米之 内^而當_層23〇包含無機材料如本較佳實施例所揭露之氧化 =時，^衝層23〇之厚度係可減少至數千埃之内。因此，緩衝層 響到軟性顯示器元件的可撓特性。且因氧化石夕層之厚度 眺㈣之㈣料谢因氧切層 明應力問題，即可藉此實施例消失；繼而本發 月斤知供之1作方法更可減少緩衝層帽縫的發生。 動元緩衝層230之後’即可開始形成主動元件，·此種主 ==依整體設計而有多種不同變化。請參閱第5圖至 圖此為本發明所提供之-實施例；其在形成緩衝層230之 201113843 後製作的主動元件，結構如圖中的如薄膜電晶體(TFT) 240與書素 電極260。如第5圖所示，於緩衝層230上形成TFr 的一閘極 金屬層242。接下來如第6圖所示’於閘極金屬層242上形成一閘 極絕緣層244、一半導體層246與一源極/沒極金屬層2你。如第7 圖所示，隨後於源極/沒極金屬層248與閘極絕緣層244上形成一 具有開口圖案之背向通道保護層(back_channel passivatiQn，Bp) 250，如一絕緣之氮化矽層’與畫素電極26〇，如一氧化銦錫 tin oxide ’ ITO)層或氧化銦辞(in(jium zinc 〇别6，ιζο)層。書素電 • 極260係如第7圖所示，藉由背向通道保護層250之開口與源極/ 汲極金屬層248電性連接。如上之TFr24〇的各層與畫素電極26〇 之製作’可藉由多道沈積製程與微影暨蝕刻製程 (photoetching-process ’ PEP)完成；而其相關之製程可由業界週知 之技術達成’故此不再加以贅述。 請參閱第8圖，於完成此實施例之主動元件後，亦即，完成 TFT 240與晝素電極26〇的製作後，則對承載基底2〇〇與金屬層 220進行一分離處理。在本較佳實施例中，分離處理可為一雷射處 鲁理如氣化成準分子雷射處理(XeCl eximer Laser)。其對承 載基底200之第二表面2〇4施以一波長約為3〇8奈米(觸咖如， nm)的雷射，由於承载基底2〇〇透光的特性，雷射的能量會由第二 表面204直接穿透承載基底2〇〇而到達犧牲層21〇。也就是說，在 雷射處理270時’犧牲層21〇會吸收雷射的能量，使得非晶石夕材 料被轉換成多晶矽材料。與此同時，犧牲層22〇内的氫原子將被 釋放出來而產生氫爆(hydrogen decrepitati〇n)，並導致金屬層22〇 與承載基板200分離；而分離後的金屬層22〇即成為軟性顯示器 元件的可撓性基板。另外值得注意的是，在雷射處理27〇後，犧 201113843 仍附著於承载基底細上而與金顧22〇分離，因 藉由其他處理移除承餘底·上的犧牲層加，而讓承麟底 態’因此可供再次使用，細可節省整體的承載基 了岡,ΓίΓΓ供之概齡11元件之製作料，首先係提供 屬使得犧牲層210、後續作為金屬軟板的金 2屬00層Γ G與絲元件如ΤΚΓ24_料於承載基底 理完作’確航件製作的良率。接下來分離處The production method provided by the month is to provide rigid stability of the active substrate by the carrier substrate, so that the active tree can be well fabricated on the metal layer and the buffer layer; a... the processing process enables the Jinlang and the buffer layer with the active component to be combined with the carrier layer. Cheng County was replaced by a soft (four) metal substrate, and finally a metal soft TFT substrate was obtained. [Embodiment] π refers to Figs. 2 to 8 which are the slits of the manufacturing apparatus of the flexible display device of the present invention: 16 cases. As shown in Fig. 2, the present invention first provides a carrier substrate • ' which defines a first surface 2〇2 and an opposite second surface 2〇4. The carrier substrate 200 is a light transmissive substrate, which may include a light transmissive material such as glass, quartz or sapphire, and then is formed on the first surface 202 of the carrier substrate 2 to form a sacrificial layer 21, and the thickness of the layer 210 is less than 5 〇〇. In the preferred embodiment, the sacrificial layer 21 is formed by chemical vapor deposition (hereinafter referred to as c, the process is formed on the first surface 2〇2, and contains amorphous tree material. In the CVD process, the hydrogen content of the sacrificial layer 21〇 can also be increased by adding a positive adjustment to the addition of nitrogen by Shi Xizheng (10). In addition, after the CVD process, the sacrificial layer 21G may be subjected to a hydrogen ion implantation process or a hydrogen ion plasma treatment to increase the hydrogen content of the sacrificial layer 210 by 201113843. Please refer to Figure 3. Next, a metal layer 22 is formed on the sacrificial layer 21〇: in this embodiment, the metal layer 220 comprises stainless steel (stainiess steei), which can be coated by sputtering or silver paste. The sacrificial layer 210 is formed by a method such as c〇ating. It is to be noted that when the metal layer 22 is formed on the sacrificial layer 210 by sputtering or silver paste coating, the surface flatness thereof is greatly improved. The thickness of the metal layer 22 can be less than 2. Therefore, the flexible display element provided in this embodiment can be a flexible display element having an ultra-thin metal substrate. "Please refer to Fig. 4. Next, a buffer layer 23 is formed on the metal layer 22, and the buffer layer 230 is used to planarize the surface of the metal layer 22, and to avoid the formation of components formed after the metal layer. The capacitive coupling effect, so the buffer layer (4) may comprise an insulating organic material or an inorganic material such as an oxygen-cut or nitride material to provide electrical isolation between the metal layer 220 and the component. It is worth noting that the buffer layer is below 0. The surface flatness of the metal layer 22G has been greatly improved, so the buffer layer must be increased in thickness to match the flatness of the metal layer 22, and the flattening effect can be achieved. When the buffer layer 230 contains organic materials. The thickness of the layer 23 can be reduced to a few thousand angstroms. Therefore, when the layer 23 contains an inorganic material such as the oxidation of the preferred embodiment, the thickness of the layer 23 can be reduced to several thousand angstroms. The buffer layer oscillates to the flexible characteristics of the flexible display element, and because of the thickness of the oxidized stone layer (4) (4), the Xie oxygen cut layer has a clear stress problem, and the embodiment can be eliminated; 1 method can reduce the slowdown The occurrence of the punching of the cap layer. After the movable element buffer layer 230, the active element can be formed. This type of main == has various changes depending on the overall design. Please refer to Fig. 5 to Fig. - an embodiment; an active device fabricated after forming the buffer layer 230 of 201113843, as shown in the figure, such as a thin film transistor (TFT) 240 and a pixel electrode 260. As shown in Fig. 5, formed on the buffer layer 230 A gate metal layer 242 of TFr. Next, as shown in FIG. 6, a gate insulating layer 244, a semiconductor layer 246 and a source/electrode metal layer 2 are formed on the gate metal layer 242. As shown in FIG. 7, a back-channel passivati Qn (Bp) 250 having an opening pattern, such as an insulated tantalum nitride layer, is formed on the source/deion metal layer 248 and the gate insulating layer 244. With the pixel electrode 26〇, such as indium tin oxide tin oxide 'ITO layer or indium oxide (in (jium zinc) 6, ζ layer). The book element is shown in Figure 7, by The opening facing away from the channel protection layer 250 is electrically connected to the source/drain metal layer 248. As above, TFr24 The fabrication of each layer and the pixel electrode 26 can be accomplished by a multi-pass deposition process and photoetching-process 'PEP; and the related processes can be achieved by well-known techniques in the industry' and therefore will not be described again. Referring to FIG. 8, after the active device of this embodiment is completed, that is, after the fabrication of the TFT 240 and the halogen electrode 26 is completed, the carrier substrate 2 and the metal layer 220 are separated. In the preferred embodiment, the separation process may be a laser treatment such as gasification into a XeCl eximer laser. It applies a laser having a wavelength of about 3 〇 8 nm (touch, for example, nm) to the second surface 2 〇 4 of the carrier substrate 200, and the energy of the laser is due to the light transmission property of the carrier substrate 2 The second surface 204 directly penetrates the carrier substrate 2 to reach the sacrificial layer 21A. That is, at the time of laser processing 270, the sacrificial layer 21 吸收 absorbs the energy of the laser, so that the amorphous stone material is converted into a polycrystalline germanium material. At the same time, the hydrogen atoms in the sacrificial layer 22 will be released to generate hydrogen decretation, and the metal layer 22 is separated from the carrier substrate 200; and the separated metal layer 22 becomes soft. A flexible substrate for a display element. It is also worth noting that after the laser treatment of 27〇, the sacrifice 201113843 is still attached to the load-bearing base and separated from the Jingu 22〇, because the other layers are used to remove the sacrificial layer on the bottom of the bearing. The bottom state of Chenglin' is therefore reusable, and the overall load-bearing base can be saved. The material of the 11-element element is provided. Firstly, the genus is provided with the sacrificial layer 210 and the subsequent metal genus as a metal soft board. The 00 layer Γ G and the silk element, such as ΤΚΓ24_, are expected to be used as the yield of the carrier. Next separation
Lt .等方法所提供的能量，而使得犧牲層產生氫 屬層220與承載基底2⑻的分離，成魏獲_欲取2 性金屬軟板。由於本發财金屬層22G係藉由频或銀膠 fit 於犧牲層210上，因此其表面平坦度大為改善， 使付後續形成於金屬層挪上的緩衝層23()厚度亦可隨之降低， 避，了因緩衝層230過厚造成的可撓性降低問題與應力、裂縫等 問題。 也就是說，根據本發騎提供之紐，射_輕成軟性 勤不器讀金屬基底的製作，取得金屬軟板耐高溫、低熱膨服係 f、較佳阻水氣阻氧氣能力、低靜電效應等優點。且由於金屬軟 π較佳阻水乳、阻氧氣的特性，根據本發明所提供之方法製作而 件的軟性顯示ϋ金屬基底，亦適合作為非液晶麵示器之基底， 如有激發光二極體㈣心娜細出㈣驗⑽聊示器之基 底’以克服有機發光材騎水氣與氧氣的敏制題，因此可不限 ^上述LCD TFT基板之製作。同時藉由濺鍍或縛_等方式改 :了金屬軟板最大的缺點，即表面平坦度關題，也因此可降低 緩衝層的厚度，更加避免了緩衝層230過厚造成的可撓性降低問 201113843 題與應力、裂鏠等問題。此外’由於本發明所提供承載基底係可 重複利用，更可節省承載基底之使用成本。 【圖式簡單說明】 第1圖係為一習知金屬軟性TFr基板之剖面示意圖。 第2圖至第8圖所繪示為本發明所提供之軟性顯示器元件之 製作方法之一較佳實施例之示意圖。 【主要元件符號說明】 100 102 金屬軟性薄膜電晶體基板 104 金屬基底 106 小田L 穴點 108 元件 110 緩衝層 200 微粒 202 承載基底 204 第一表面 210 第二表面 220 犧牲層 230 金屬層 240 緩衝層 242 薄膜電晶體 244 閘極金屬層 246 閘極絕緣層 248 半導體層 250 源極/汲極金屬層 260 背向通道保護層 270 畫素電極 d 雷射處理 線寬The energy provided by the method, etc., causes the sacrificial layer to separate the hydrogen layer 220 from the carrier substrate 2 (8), and to obtain a bismuth metal soft plate. Since the carbon layer 22G of the present invention is made of a frequency or a silver paste on the sacrificial layer 210, the surface flatness thereof is greatly improved, and the thickness of the buffer layer 23 () which is subsequently formed on the metal layer can be increased. The problems of reduction in flexibility, stress, cracks, and the like due to excessive thickness of the buffer layer 230 are reduced and avoided. That is to say, according to the New Zealand provided by the hairpin, the light_softness is soft and the metal substrate is not read, and the metal soft board is resistant to high temperature, low heat expansion, f, better water resistance, oxygen resistance, low static electricity. Effects and other advantages. And because of the metal soft π preferred water blocking emulsion and oxygen barrier properties, the soft display of the metal base is made according to the method provided by the invention, and is also suitable as a substrate for a non-liquid crystal display, such as an excitation light diode. (4) The heart is fine (4) Test (10) The base of the talker' to overcome the sensitive problem of the organic light-emitting material riding water vapor and oxygen, so it is not limited to the above-mentioned LCD TFT substrate. At the same time, by sputtering or binding, etc., the biggest disadvantage of the metal soft board is that the surface flatness is the same, so that the thickness of the buffer layer can be reduced, and the flexibility of the buffer layer 230 excessively thick is further avoided. Ask 201113843 questions and stresses, cracks and other issues. In addition, since the carrier substrate provided by the present invention can be reused, the use cost of the carrier substrate can be saved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view of a conventional metal soft TFr substrate. 2 to 8 are schematic views showing a preferred embodiment of a method for fabricating a flexible display device according to the present invention. [Main component symbol description] 100 102 metal flexible thin film transistor substrate 104 metal substrate 106 Oda L point 108 element 110 buffer layer 200 particles 202 carrier substrate 204 first surface 210 second surface 220 sacrificial layer 230 metal layer 240 buffer layer 242 Thin film transistor 244 gate metal layer 246 gate insulating layer 248 semiconductor layer 250 source/drain metal layer 260 back channel protection layer 270 pixel electrode d laser processing line width