1231046 玖、發明說明： 【發明所屬之技術領域】 本發明是有關於一種低溫多晶石夕薄膜電晶 之雷射再結晶方法，尤指—種可使通道内 ^ 但不需額外光罩，且同時達到提升元件特性^ = 均勻度與節省製程成本之功效。 獒件 【先前技術】 按，一般傳統非晶矽薄膜電晶體液晶 时 :⑽D)因為價格持續滑落，再加上低溫多晶 W晶體液晶顯示器在小尺寸的應用領域曰漸普及， 而5亥低溫多晶石夕的薄膜電晶體液晶顯示器具有解析产、 =、Γ及電磁干擾等各方面的優勢，並已逐漸：個 =理、數位相機、行動電話等行動終端設備中取 其中在傳統雷射退火低溫多晶矽薄雕 (LTPS-TFT)的製造步驟上，合先 \日日肢 射再結晶後衫義電晶體主鮮進行雷 人/ 兒日日版主動層，可是如此矽晶粒大小 曰^限於薄膜厚度而無法變更大且不規則的石夕晶粒大小 分佈於電晶體主動層内會導致㈣與元件之間電特性上 的是異而使均勻性變差，但是，若Μ義電晶體主動層 再進仃雷射再結晶’則主動層會时薄膜全料融時所 造成的表面張力而對主動層產生微縮現象（Surface Tension induced Shr丨nkage)，如此方法不適用於低溫多 1231046 晶矽薄膜電晶體的製造； 另外多晶石夕薄膜電晶體（丁FT)和石夕絕緣層上的金 屬乳化物半導體場效電晶體（s〇|_m〇sfet)等元件其 主動層下方為一層導熱效率較差的絕緣層，如此當元;牛 工作在大電流時’主動層的溫度會瞬間上升，載子於主 ^層^移動率會因此而下降，便有相關技術者提出將 變成很多小通道寬度w丨的並聯來改善這自 =、、、效應（self_heatingEffect)如第7圖所示，其係 為傳統解決自我發熱效應的方式。 【發明内容】 體（lt$s月要 '的，在於可使低溫多晶石夕薄膜電晶 2件之間的差I之場效載子移動率提高並可降低元件與 ，/、’利用此方法來製作電晶體時，當通道 小’通道内㈣晶粒越大，如此用來製作驅動佥 :曰U體可使顯示器之解析度大幅提升，此外雷射再 ;:a二:二(:rocess window)變寬，並且改善了低溫 旦Γ ^ ”的電特性’同時使元件與元件間的差 異變小，均句性坦斗 左 徒升如此可改善產品良率。 發明之另—目的，係在於可具有連續波長 (continuous wavp ρ\Λ/λ ^ ^ ^ m m )雷射或準分子（Exci_)命 射退火後觸發炫融石夕側向士曰 田 升場效載子移動玄'隹 機制，因此可大幅提 =載子移動率進而改善元件特性，但製 外光草，且厚的間距發㈤ 1231046 在雷射照射後不會微縮變形，若利用高能量雷射對狗骨 ^ $狀（dqig. bone Shape )的主動層經源極—汲極 S0urce-Dram)方向進行掃猫，可得到單獨一顆石夕晶 粒於電晶體通道内的狀況，進而可製作高性能（_ ^_nCe)、高均勻度_咖jty)的低溫多 1缚版電晶體’用本發明來實現較大通道寬度〜的元 牛τ可以利用小通道見度Wi並聯的方式以符合各種電 流需求，如此仍可保持較大矽晶粒於通道内，且可順便 改善元件自我發熱效應（Se|f_heating Effect)。、 為達上述之目的’本創係—種低溫多晶㈣膜電晶 體主動層之雷射再結晶方法，包含下列步驟： 步驟一 ··提供一基板； 步驟二：該基板上係形成一緩衝氧化層 Oxide); 步驟三：在該緩衝氧化層上沈積一非晶矽薄膜層 (amorphous silicon); 步驟四·再於該非晶石夕薄膜層上沈積一低溫氧化層鲁 (L⑽Temperature〇x丨de)，而該低溫氧化層係為了作· 為後續製程時，矽薄膜非等向性電漿蝕刻（Anis〇tr〇pjc ，1231046 发明 Description of the invention: [Technical field to which the invention belongs] The present invention relates to a method for laser recrystallization of a low-temperature polycrystalline crystalline thin film transistor, in particular, a method that allows the inside of a channel ^ but does not require an additional mask, At the same time, it can achieve the effect of improving component characteristics ^ = uniformity and saving process costs. Article [Previous technology] According to the conventional traditional amorphous silicon thin film liquid crystal: ⑽D) because the price continues to fall, coupled with the low-temperature polycrystalline W-crystal liquid crystal display in the field of small-sized applications, and the low temperature Polycrystalline thin film transistor liquid crystal displays have the advantages of analytical production, =, Γ, and electromagnetic interference, and have gradually evolved from traditional mobile lasers to mobile terminals such as cameras, digital cameras, and mobile phones. In the manufacturing steps of annealed low temperature polycrystalline silicon thin sculpture (LTPS-TFT), the first step is to re-crystallize the body, and the main body of the transistor is to perform the active layer of the thunder / children's day version, but this is the size of the silicon grains ^ Due to the thickness of the film, it is not possible to change the large and irregular distribution of the crystal size of the stone in the active layer of the transistor, which will cause the difference in the electrical characteristics between the element and the element to deteriorate the uniformity. The active layer is re-injected into the laser and recrystallized. The surface tension of the active layer caused by the thin film melting during the active layer will cause the active layer to shrink (Surface Tension induced Shr 丨 nkage). This method is not applicable. For the manufacture of polycrystalline silicon thin film transistors at low temperature 1231046; In addition, polycrystalline silicon thin film transistors (FT) and metal emulsion semiconductor field effect transistors (s〇 | _m〇sfet) on the insulating layer of Shi Xi Under the active layer is an insulating layer with poor thermal conductivity, so when the current is high, the temperature of the active layer will rise instantaneously when the cow is working at a high current, and the carrier's mobility in the main layer will decrease accordingly. It is proposed to improve the self-heating effect in parallel by turning many small channel widths w 丨 as shown in Fig. 7, which is a traditional way to solve the self-heating effect. [Summary of the Invention] What is necessary is to increase the field-effect carrier mobility of the difference I between the two pieces of low-temperature polycrystalline silicon thin film transistors and reduce the component and / When this method is used to make a transistor, when the channel is small, the crystal grains in the channel are larger, so it is used to make the driver: U body can greatly improve the resolution of the display, and in addition, the laser is again; : rocess window) is widened, and the low-temperature denier Γ ^ "electrical characteristics" is improved, and the difference between the components is reduced. The uniform sentence can be used to improve the product yield. , Because it can have a continuous wavelength (continuous wavp ρ \ Λ / λ ^ ^ ^ mm) laser or excimer (Exci_) life-trigger annealing to trigger the Xuan Rong Shi Xi side to Shi Yuetian ascendant field mover Xuan '隹 mechanism, which can greatly improve the carrier mobility and improve the device characteristics, but the outer light grass, and thick pitch hair ㈤ 1231046 will not shrink and deform after laser irradiation. If high energy laser is used to dog bone ^ The active layer of $ 状 （dqig. Bone Shape） goes in the direction of source-drain Source-Dram. Sweep the cat to obtain a single Shi Xi crystal grain in the transistor channel, and then can produce high-performance (_ ^ _nCe), high uniformity _ coffee jty) low-temperature multi-layer version of the transistor 'Using the invention In order to achieve a larger channel width, the Yuan Ni τ can use the small channel visibility Wi in parallel to meet various current requirements, so that a larger silicon die can still be kept in the channel, and the self-heating effect of the component can be improved by the way (Se f_heating Effect). In order to achieve the above-mentioned purpose, the “inventive system” —a low-temperature polycrystalline holmium film transistor active layer laser recrystallization method, includes the following steps: Step 1 ·· Provide a substrate; Step 2: The substrate A buffer oxide layer (Oxide) is formed on the system; step three: depositing an amorphous silicon film layer on the buffer oxide layer; step four: depositing a low-temperature oxide layer on the amorphous stone film layer ( L⑽Temperature〇x 丨 de), and the low-temperature oxide layer is for the subsequent process, the silicon film anisotropic plasma etching (Anis〇tr〇pjc,
Plasma Etching)的停止層、雷射退火時防止熱量散逸 的保溫層和作為再結晶後去除間距矽的硬式光罩（H a「d Mask ); 步驟五：之後利用一光阻層（Ph〇t〇「esist)作為硬 !231〇46Plasma Etching) stop layer, thermal insulation layer to prevent heat dissipation during laser annealing, and a hard mask (H a "d Mask) that removes the spacing silicon after recrystallization; Step 5: Then use a photoresist layer (Phot 〇 "esist" as hard! 231〇46
式光罩，利用非望A 後再部分蝕刻下方_曰電:钱刻將低溫氧化層完全敍刻 J非日日矽潯膜層； 步驟六··去除光阻層後 時，原本下方之非晶石夕積;^另—非晶石夕薄膜層 接’再以非等向#電；;::亥非晶矽薄膜層相 接下來執行非W主動心2間㈣於主動層邊緣， 再結晶後，即可使主動射或準分子雷射 等向性電漿_完全去除間距:二=利用非 化層。 王動層上方的低溫氧 【實施方式】 方'7圖』’係本發明之成形之垂直電流 Γ置:意圖、本發明之重要描述在電晶體上二 r視圖、本發明之SEM (Sc— Electron 咖scope)圖、本發明在使用連續波長（⑽ wave，W)雷射再結晶時主動層圖形方位與雷射掃瞒方向 =意圖、習用解決較大通道寬度電晶體自我發熱效應 (Self-heatlng Effect)方式之示意圖。如圖所示：本 發明係一種低溫多晶矽薄膜電晶體（ltps_tft )主動層 之雷射再結晶方法，包含下列步驟： 步驟 提供一基板 步私一 · 4基板1上係形成一緩衝氧化層2 (-Type photomask, using the non-Wang A and then partially etching the bottom _ said electricity: Qian engraved the low-temperature oxide layer completely J non-Japanese silicon silicon film layer; Step 6 · After removing the photoresist layer, the original non- Spar slab; ^ Another—amorphous slab thin film layered and then non-isotropic #electrical ;;: Hai amorphous silicon thin film layer phase next performs a non-W active center 2 between the active layer edge, and After crystallization, you can make the active or excimer laser isotropic plasma _ completely remove the distance: two = use of non-chemical layer. Low-temperature oxygen above the king ’s layer [Embodiment] The square '7 figure' is the vertical current Γ of the present invention: intended, important description of the present invention, two r views on the transistor, SEM (Sc— Electron (scope) diagram, the present invention, when using continuous wavelength (⑽ wave, W) laser recrystallization, the active layer pattern orientation and laser sweep direction = intention, custom to solve the self-heating effect of larger channel width transistor (Self- heatlng Effect) method. As shown in the figure, the present invention is a laser recrystallization method for an active layer of a low temperature polycrystalline silicon thin film transistor (ltps_tft), which includes the following steps: Steps Provide a substrate Step 4 • A buffer oxide layer 2 is formed on the substrate 1 (
Oxide ); 步驟三：在該緩衝氧化層2上沈積一非晶矽薄膜層 1231046 3 (amorphous silicon); 步驟四：再於該非晶石夕薄膜層3上沈積一低溫氧化 層4 (Low Temperature 〇xide)，而該低溫氧化層4係 可作為後續製程時，矽薄膜非等向性電漿蝕刻 (Anisotropic Plasma Etching)的停止層、雷射退 1 時防止熱量散逸的保溫層和作為再結晶後去除間距石夕 (silicon-spacer)的硬式光罩（Hard Mask); ，〜1夂〜用且！ imotoresist) 5作為 硬式光罩，利用非等向性電黎钱刻8將低溫氧化層〇 全姓刻後再部分_下方的非晶”膜層3; 步,1:去除光阻層5後再沈積上另一非晶石夕薄膜 二：;原：下方之非晶石夕薄膜層3會與該非晶石夕薄膜 層3a相接，再以非等向性電漿_8形成間㈣7於主 =邊緣’接下來執行非晶石夕主動層的連續波長或準分 子田射再後，即可使主動層㈣ =用非等向性完全去㈣距w與主$ 上方的低溫氧化層4。 曰 以上所述之該間距矽Oxide); Step 3: deposit an amorphous silicon film layer 1231046 3 (amorphous silicon) on the buffer oxide layer 2; Step 4: deposit a low temperature oxide layer 4 (Low Temperature 〇) on the amorphous stone film layer 3 xide), and the low temperature oxide layer 4 can be used as a stop layer for anisotropic plasma etching (Anisotropic Plasma Etching) of the silicon film during the subsequent process, a thermal insulation layer to prevent heat dissipation when the laser exits 1, and after recrystallization Remove the hard mask of the silicon-spacer; ~ 1 夂 ~ Use it! imotoresist) 5 as a hard mask, using a non-isotropic electrical Li Qian engraved 8 low temperature oxidation layer 〇 full name and then partially _ below the amorphous "film layer 3; step, 1: remove the photoresist layer 5 and then Another amorphous stone film 2 is deposited on the original: the original amorphous stone film layer 3 below will be connected to the amorphous stone film layer 3a, and then the non-isotropic plasma _8 will be used to form the gap 7 on the main = Edge 'Next, the continuous wavelength of the active layer of the amorphous stone or the field emission of the excimer can be used to make the active layer ㈣ = Use anisotropy to completely remove the distance w from the low-temperature oxide layer 4 above the main $. The pitch silicon mentioned above
(Λ /加可包括複晶矽薄I (polycrystalline silicon fn 、 t r 〇n film )與非晶矽薄用 (amorphous silicon ^ , ilc〇n iUnO所形成 且該步驟六中製作間距料 （SPaCer)((Λ / plus can be formed by polycrystalline silicon thin film I (polycrystalline silicon fn, tr 〇n film) and amorphous silicon thin film (amorphous silicon ^, ilcoon iUnO), and a spacer material (SPaCer) is prepared in this step 6.)
、包括用於潯膜電晶體（TFT 、、、巴、’彖g上的金屬氧化物半日 帝曰 (S0I-M0SFET)之主動層邊緣 琢效电日日- (匕έ填入主動層邊緣下 1231046 方處）’且不論高、低溫製程都適用此方法。另，該步驟 六中製作間距石夕薄膜電晶體之主動層邊緣後再進行雷射 再結晶’此間距石夕主要目的是製造一溫度梯度導致矽薄 膜側向再結晶。且該步驟六中覆蓋於薄膜電晶體之主動 層側壁的間距石夕可以換成介電質（如〇xide、NitHde、 Metal oxide…等）或金屬（如鋁A1、鎢w、鉬M〇、鉻 Cr…）等材料代替，最後再將間距矽選擇性去除 接留下）後繼續往下的製程。另外，該步驟六亦可先利 用準分子雷射退火（ELA)、目相結晶⑽）或金屬致側 向再結晶UIIX)等方法先對主動層再結晶後，再製作 間距石夕於薄膜電晶體切絕緣層上的金屬氧化物半導體 場效電晶體之主動層邊緣。 忒間距矽7被製作在主動層非晶矽薄膜層3的邊 緣後’可用南能量連續波長雷射對狗骨頭形狀（岭匕㈣ 咖⑷的主動層進行再結晶，或以準分 雷射進f再結晶9，其間可使主動層產生-溫度梯1 而使矽晶粒變大（如第3圖所示）； 由該第4圖觀之’其係顯示了間極 源極 1 1 (Source)、汲極2 2 f (Gate)與 双杜 Z ( Drain)之 可看到如此之製程，在雷射再結晶之 ， 繞整個主動層（非晶㈣膜層3 …距碎7會環 向性電槳㈣8沒有完全去除間距石夕7 交，的非寺 石夕7並不會對電晶體的電特性產㈣、〜餘的間距 心向，因為間距矽7 10 1231046 的^曰曰特性很差’電壓很難使間距矽7導通進而對電流 產生貢獻。 第5圖是利用準分子雷射再結晶所得的多晶矽晶粒 Grains)於通道内的分佈狀況，此可證明本 $明可侍較大的矽晶粒於電晶體的通道内，其中原因是 口為在田射照射後較薄的通道區域全部熔融，但較厚的 曰夕7則部分炫融，全部熔融的區域會以間距矽7為 種（seed)而觸發往内再結晶，此外，由第5圖亦可 戶、J X主動層邊緣沒有微縮（Shrinkage)變形的現象， 所以坆方法可以有效的抑制矽薄膜全部熔融後表面張力 ^導致的u縮效應（Shrinkage Effect);而該第6圖為 1方法在使用連續波長雷射再結晶時主動層圖形方位盥 方向之最佳狀況，另，第7圖其係為傳議 發熱效應的方式，本發明可進一步利用此方式搭配 較大通道寬度w電晶體日_小通道寬度 石… 符合各種電流需求，如此仍可保持較大 曰曰粒於通，内’且可順便改善元件自我發熱效應。 由乂上°羊細况明’可使熟知本項技藝者明瞭本發明 專利=成前述目的’實已符合專利法之規^，羞提出 惟以上所述者，僅為本發明之較佳實施例而已，各 =以此限定本發明實施之範圍；故，： 專利範圍及創作說明書内容所作之簡單料效 1231046 飾，皆應仍屬本發明專利涵蓋之範圍内。 1231046 【圖式簡單說明】 第1 2、3目，係本發明之成形之垂直電流方向剖面 示意圖。 第4圖，係本發明之重要描述在電晶體上的相對位置俯 視圖。 第 5 圖，係本發明之 SEM (Scanning Eiectr〇n Microscope)圖。 第6圖，係本發明在使用連續波長（⑶ntinuous wave， CW)雷射再結晶時主動層圖形方位與雷射掃瞄 方向之示意圖。 第7圖，習用解決較大通道寬度電晶體自我發熱效應 (Self-heating Effect)方式之示音圖。 【圖號說明】 心口 緩衝氧化層2 低溫氧化層4 間距矽7 基板1 非晶矽薄膜層3、3 a 光阻層5 非等向性電漿蝕刻8 動層的連續波長或準::，結晶9 汲極1 2 13, Including the edge of the active layer for the metal oxide film transistor (TFT ,,,, and the metal oxide half-day Emperor's (S0I-M0SFET)) to cut the electric day-(dagger filled under the edge of the active layer 1231046 square) 'and this method is applicable regardless of the high and low temperature process. In addition, in step six, the active layer edge of the Shishi thin film transistor is made and then the laser is recrystallized. The temperature gradient leads to the lateral recrystallization of the silicon thin film, and the distance between the side walls of the active layer covering the thin film transistor in step 6 can be changed to a dielectric (such as 0xide, NitHde, Metal oxide, etc.) or a metal (such as Aluminum A1, tungsten w, molybdenum M0, chromium Cr ...) and other materials are replaced, and finally the distance silicon is selectively removed and then left) to continue the process. In addition, in step 6, the active layer may be first recrystallized by using methods such as excimer laser annealing (ELA), mesh phase crystallization) or metal-induced lateral recrystallization (UIIX). The crystal cuts the edge of the active layer of a metal oxide semiconductor field effect transistor on the insulating layer.忒 Pitch silicon 7 is fabricated behind the edge of the active layer amorphous silicon thin film layer 3 '. The dog bone shape can be recrystallized with a South-energy continuous-wavelength laser (the active layer of the ridge dagger or the calyx laser). f recrystallizes 9, during which the active layer can generate-temperature ladder 1 to make the silicon grains larger (as shown in Figure 3); from the view in Figure 4 'its system shows the interpolar source 1 1 ( Source), Drain 2 2 f (Gate) and Shuang D Z (Drain) can be seen in such a process, recrystallized in the laser, around the entire active layer (amorphous rhenium film layer 3… a distance of 7 will ring The directional electric paddle 8 does not completely remove the pitch Shi Xi 7, and the non-temple Shi Xi 7 will not produce electrical characteristics of the transistor, and the remaining pitch is centered, because the characteristics of the pitch silicon 7 10 1231046 are very The difference 'voltage is difficult to make the pitch Si 7 conductive and thus contribute to the current. Figure 5 is the distribution of polycrystalline silicon grains (Grains) in the channel obtained by recrystallization of excimer laser, which can prove that this can be compared. The large silicon grains are in the channel of the transistor. The reason is that the mouth is thinner in the channel area after field irradiation. It melts, but the thicker Yuxi 7 is partially melted, and all the melted regions will trigger inward recrystallization with the pitch of silicon 7 as seed. In addition, as shown in Figure 5, the edge of the JX active layer is not Shrinkage deformation phenomenon, so the 坆 method can effectively suppress the shrinkage effect (shrinkage effect) caused by the surface tension of the silicon film after all melting; and Figure 6 shows the method 1 when using continuous wavelength laser recrystallization The best situation of the active layer graphic orientation and direction. In addition, Figure 7 is a way to discuss the heating effect. The present invention can further use this method with a larger channel width w transistor day _ small channel width stone ... The current demand can still be kept large, so it can improve the self-heating effect of the components by the way. From the details of the sheep, the skilled person will be able to understand the patent of the invention = to achieve the aforementioned purpose 'It is actually in compliance with the regulations of the Patent Law ^, but the above mentioned are only the preferred embodiments of the present invention, each = to limit the scope of the implementation of the present invention; therefore, the scope of the patent and the description of the creation The simple material effect 1231046 decoration made in the book content should still fall within the scope of the patent of the present invention. 1231046 [Simplified illustration of the drawings] Items 1 and 2 are schematic cross-sectional schematic diagrams of the vertical current direction of the invention. Section 4 The figure is a plan view of the relative position on the transistor, which is an important description of the present invention. Figure 5 is a SEM (Scanning Eiectron Microscope) diagram of the present invention. Figure 6 is a continuous wave (CDntinuous wave, (CW) Schematic diagram of the active layer pattern orientation and laser scanning direction during laser recrystallization. Figure 7: Acoustic diagram used to solve the self-heating effect of a transistor with a large channel width. [Illustration of the drawing number] Heart buffer oxide layer 2 Low temperature oxide layer 4 Pitch silicon 7 Substrate 1 Amorphous silicon thin film layer 3, 3 a Photoresistive layer 5 Anisotropic plasma etching 8 Continuous wavelength or quasi ::, Crystal 9 Drain 1 2 13