200848541 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種奈米碳管之製備方法，尤其涉及一種 分枝型奈米碳管之製備方法。 【先前技術】 奈米碳管（CNTs)自90年代初由日本學者η以脈發現 以來（IijimaS·，Nature，1991，354(7)，56-58)，立即 引起科學界及產業界之極大重視，係近年來國際科學研究 之熱點。奈米碳管由六元環組成之石墨片層結構捲曲而形 成之同心圓筒構成。分枝型奈米碳管因其三維管狀結構而 具有獨特之電學開關性及導熱性。隨著現代電子工藝更— 步地微型化，分枝型奈米碳管可作為電極材料、聚合物增 強角1]、電晶體或電化學產品而廣泛地應用於奈米尺度之電 晶體、放大器或電極材料等方面。 ^先前之㈣分枝型奈織管之方㈣電贼電法及化 學氣相沈積法（Chemical Vapor Deposition，CVD)。其中， 通過電弧放餘製備之倾型奈讀管之產率極低;從而 ，制了該方法之推廣。目前，⑽法為製備分枝型奈米碳 官之主要方法。該方法為利用含有分枝型通孔之模板，於 通孔中线分枝型奈米碳管，或者利用揮發性有機金屬化 合物於高溫下分解而得到分枝型奈米石炭管。然，利用模板 f方法製備分枝型奈米碳管過程複雜，且所得到之奈米碳 管之品!較差；利用有機金屬化合物分解之方法製備分枝 型奈米碳管，因金屬催化劑係於氣相下分解，不容易實現 200848541 分枝型奈米碳管之定位生長，不利於奈米碳 件中之應用。 蚊兒子态 有繁於此，提供-财實現定位生長、有利於後期應 用之分枝型奈米碳管之簡單㈣方法實爲必要。… 【發明内容】 ^下以實齡m明—齡枝型奈錢f之製 其包括以下步驟： 提供-基底；形成—隔離層於該基底之表面 催化劑層於該隔離層之表面，於奈米碳管之生 料係互不浸潤;將表；編 ==細丨狀基底置於—反麟内；加熱使反應爐之溫 X達到-預疋溫度，通人倾氣退火—段_後，再往反 應爐内通^碳源氣，反應—段時間即得到分枝型奈米碳管。 、與先前技術相比，該分枝型奈米碳管之製備方法具有 =下優點：⑴以乙块、m、乙烯等純碳氫氣體為碳源 乳’降低了生產成本；⑵採用鍍膜之方法製備催化劑層， 故可利用光刻等方法以實現奈米碳管之定位生長；⑶製 備出之分枝型奈米碳管多數頂端包覆有金、銀、銘等導電 性佳之金屬’從而提高了奈米碳管與電路之電性連接，有 2奈米碳管之後期應用；⑷該方法製備之分枝型奈米 石厌官之產率可達到50%。 【實施方式】 下面將結合附圖對本發明實施例作進一步之詳細說 明。 17 8 200848541 種分枝型奈米碳管之生長 請參閱圖1，本發明提供一 方法，具體包括以下步驟： 面、』驟一:1先提供一基底1()，並於該基底1◦之-表 面沈隔離層12。基底1G之材料可知、玻璃、石# 該隔離層12為通過熱沈積、電子束蒸鍍或濺射等方= 形成之氧魅、二氧化料材料，該隔離層 於度為大 於本實施射，基底1Q之材料切， 過好束蒸鍍絲絲聽Π)上之厚賴為 鋁層。 〜平 丄步驟二：形成一催化劑層14於隔離層12之表面。催 化剖層14為通過熱沈積、電子束蒸鑛、或濺射等方法形成 ，金、銀、銅、翻、錯等導電性佳之貴金屬材料。該催化 劑層之厚度為0.5nm至1.5nm。於奈米碳管之生長溫度下， 催化劑層14與隔離層12之材料係互不浸潤。、酿又 於本實施例中，催化劑層14為通過電子束蒸渡法形成 於隔離層12上之厚度為lnm之金層。 步驟三··將表面依次形成有隔離層12與催化劑層14 之基底ίο置於一反應爐内。該反應爐為先前CVD法中常用 之管式反應爐，反應爐之直徑約為1英寸。 步驟四·加熱反應爐到一預定溫度，先通入保護氣退 火一段時間後，再通入碳源氣反應一段時間，可於隔離層 U之表面，沿平行於基底1〇表面之方向生長出分枝型奈 米石炭管16。 9 200848541 本實施例中，反應爐溫度為880〜950°C (攝氏度），優 選為900〜95(TC。該爐溫係由催化劑之種類來決定之，催 化劑不同，爐溫會相差較大。保護氣包括氬氣與氫氣，其 中氬氣之流量為〇〜丨4〇立方厘米/分鐘（sccm)，氫氣之流 量約為20〇sccm。通入保護氣退火之時間為1〇—3〇分鐘。 通入的氫氣主要作用係還原催化劑，以保持其催化活性。 叙t地，氬氣與氫氣流量比為140:200，反應時間為烈分 鐘。石麵氣為乙炔、甲烧、乙烯、—氧化石炭或乙醇等氣體刀， 通入妷源氣之流量為1〇〜5〇sccm，反應時間為5分鐘至刈 分鐘。優選地，以乙炔作為碳源氣，流量為1〇〜25此⑽， 反應時間為15分鐘。 凊苓閱圖2及圖3，於本發明所提供之分枝型奈米碳 官16之製備過程中，分枝型奈米碳管16之具體生長過程 如下： ' 催化劑層14在反應爐溫度之作用下熔化，由於催化劑 層^與隔離層12互不浸潤，溶化之催化劑收縮成球形催 J顆粒，且於隔離層12之表面具有流動性。碳源氣於炫 化之催化劑顆粒表面分解、析出碳原子，從而沿平行於基 底1〇之方向生長出奈米碳管。催化劑顆粒位於奈米碳管之 ^長頂端。當兩個奈米碳管之生長頂端之催化劑顆粒相遇 時，兩個較小之催化劑顆粒可合併成一個較大之催化劑顆 粒j而後再從較大之催化劑顆粒上生長出新的奈米碳管， 即可件到Y型之分枝型奈米碳管16 (如圖2 (a)及圖3(a) 所不）。如果，該γ型之分枝型奈米碳管16之生長頂端之 10 200848541 催化劑顆粒再與另一奈米碳管之催化劑顆粒相遇，則可得 到多極的Y型之分枝型奈米碳管16 (如圖3 (b)所示）。 同理，當兩個奈米碳管之催化劑顆粒頭對頭地正面相遇即 得到丄字型或十型的分枝型奈米碳管16 (如圖3 (c)及圖 3 (d)所示），當複數奈米碳管之催化劑顆粒同時相遇即得 到多分枝型的分枝型奈米碳管16 (如圖3 (e)所示）；當 一個奈米碳管之催化劑顆粒與另一奈米碳管之侧壁相遇可 知到L型的分枝型奈米碳管i6(如圖2(b)及圖3(f) 所示）。該方法製備之分枝型奈米碳管之產率為3〇%〜5〇%。 〃該方法製備之分枝型奈米碳管16通過組裝將奈米碳 管與電子電路之電極相連，從而保證奈米碳管與電路良好 讀姆接觸。另外，由於採驗膜方法製備催化劑，故可 實現分枝型奈米碳管16之粒生長，有利於奈米碳管器件 有選擇地定向地製備。 與先前技術相比，該分枝型奈米碳管之製備方法呈有 町伽：⑴仏炔、R、乙鱗純錢氣體為碳源 孔，降低了生產成本；⑵採用鍍膜之方法製備催化劑層， 故可利用糾等方法以實現奈米碳管之定位生長 備出之分枝型奈米碳管多數頂端包覆有金、銀、 性佳之金屬，從而提高了奈米碳管與電路之電接，，: ^奈米碳管之後期制；⑷該方法製備 1 產率可達到50% 〇 丁人s之 本發明確已符合發明專利之要件遂依法 &出專議。惟’以上所述者僅為本發明之較佳實施例， 11 200848541 自不能以此限制本案之_請專利範圍 之人士援依本發明之精神所作之 舉凡熟悉本案技藝 蓋於以下_請翻範圍内。」修飾《化，皆應涵 【圖式簡單說明] 圖1係本發明實施例中分枝型奈米碳管之製備過程示 意圖。 圖2係本發明實施例中所形成之分枝型奈米碳管之掃 描電子顯微鏡（SEM)照片。 圖3係本發明實施例中分枝型奈米碳管之生長過程示 意圖。 、 【主要元件符號說明】 基底 10 隔離層 12 催化劑層 14 分枝型奈米碳管 16 12200848541 IX. Description of the Invention: [Technical Field] The present invention relates to a method for preparing a carbon nanotube, and more particularly to a method for preparing a branched carbon nanotube. [Prior Art] Since the discovery of nanocarbon tubes (CNTs) by Japanese scholars η in the early 1990s (IijimaS·, Nature, 1991, 354(7), 56-58), it immediately caused great scientific and industrial circles. Pay attention to it, which is a hot spot in international scientific research in recent years. The carbon nanotubes are composed of a concentric cylinder formed by a six-membered ring-shaped graphite sheet structure. Branched carbon nanotubes have unique electrical switching and thermal conductivity due to their three-dimensional tubular structure. As modern electronic processes are more miniaturized, branched-type carbon nanotubes can be widely used as nano-scale transistors and amplifiers as electrode materials, polymer-enhanced angles, crystals or electrochemical products. Or electrode materials and so on. ^The previous (four) branching type Nylon tube (four) electric thief electric method and chemical vapor deposition (Chemical Vapor Deposition (CVD). Among them, the yield of the tilting type read tube prepared by the arc remnant is extremely low; thus, the method is popularized. At present, the method (10) is the main method for preparing branched nanocarbons. The method is to use a template containing a branched through-hole, a branched-type carbon nanotube in a through-hole, or a branched-type nano-carboniferous tube by decomposing a volatile organometallic compound at a high temperature. However, the process of preparing the branched carbon nanotubes by the template f method is complicated, and the obtained carbon nanotubes are poorly produced; the branched carbon nanotubes are prepared by the decomposition of the organometallic compounds, because of the metal catalyst system. Decomposition in the gas phase, it is not easy to achieve the positioning growth of the 200848541 branched carbon nanotubes, which is not conducive to the application of nano carbon parts. It is necessary to provide a simple (four) method of branching type carbon nanotubes that can be used for positioning and growth, and is advantageous for later application. The invention includes the following steps: providing a substrate; forming a barrier layer on the surface of the substrate; and a catalyst layer on the surface of the spacer layer; The raw materials of the carbon nanotubes are not infiltrated with each other; the table; the == fine-shaped base is placed in the -inverse lining; the heating makes the temperature of the reactor reach X-pre-temperature, and the person is tempered to anneal- Then, the carbon source gas is passed through the reaction furnace, and the branched carbon nanotubes are obtained in the reaction period. Compared with the prior art, the preparation method of the branched carbon nanotube has the following advantages: (1) using a pure hydrocarbon gas such as a block, m or ethylene as a carbon source to reduce the production cost; (2) using a coating film The catalyst layer is prepared by using photolithography and the like to realize the localized growth of the carbon nanotubes. (3) The branched carbon nanotubes prepared by the majority are coated with gold, silver, and other conductive metals. The electrical connection between the carbon nanotube and the circuit is improved, and the 2 nm carbon tube is applied in the later stage; (4) the yield of the branched nano-stone prepared by the method can reach 50%. [Embodiment] Hereinafter, embodiments of the present invention will be further described in detail with reference to the accompanying drawings. 17 8 200848541 Growth of branched carbon nanotubes Referring to FIG. 1 , the present invention provides a method, which specifically includes the following steps: face, first step: 1 first provide a substrate 1 (), and then the substrate 1 The surface sinks the isolation layer 12. The material of the substrate 1G is known to be glass, stone #. The isolation layer 12 is an oxygen oxidant or a dioxide material formed by thermal deposition, electron beam evaporation or sputtering, and the isolation layer is greater than the present embodiment. The material of the substrate 1Q is cut, and the thick layer of the vapor-deposited wire is used for the aluminum layer. ~ Flat Step 2: Form a catalyst layer 14 on the surface of the separator 12. The catalytic fracture layer 14 is formed by a method such as thermal deposition, electron beam evaporation, or sputtering, and a noble metal material having good conductivity such as gold, silver, copper, turn, and error. The catalyst layer has a thickness of from 0.5 nm to 1.5 nm. At the growth temperature of the carbon nanotubes, the material layers of the catalyst layer 14 and the separator 12 are not infiltrated with each other. In the present embodiment, the catalyst layer 14 is a gold layer having a thickness of 1 nm formed on the separator 12 by electron beam evaporation. Step 3: The substrate 形成 of the surface layer in which the separator 12 and the catalyst layer 14 are sequentially formed is placed in a reactor. The reactor is a tubular reactor commonly used in previous CVD processes, and the diameter of the reactor is about 1 inch. Step 4: heating the reaction furnace to a predetermined temperature, first annealing into the shielding gas for a period of time, and then introducing the carbon source gas for a certain period of time, and growing on the surface of the separation layer U in a direction parallel to the surface of the substrate 1 Branched type carboniferous tube 16. 9 200848541 In the present embodiment, the temperature of the reactor is 880 to 950 ° C (degrees Celsius), preferably 900 to 95 (TC. The temperature of the furnace is determined by the type of the catalyst, and the catalysts are different, and the furnace temperatures are largely different. The shielding gas includes argon gas and hydrogen gas, wherein the flow rate of the argon gas is 〇~丨4〇 cubic centimeters per minute (sccm), and the flow rate of the hydrogen gas is about 20 〇sccm. The annealing time of the protective gas is 1〇-3〇 minutes. The main function of the hydrogen is to reduce the catalyst to maintain its catalytic activity. The ratio of argon to hydrogen flow is 140:200, and the reaction time is minute. The surface gas is acetylene, ketone, ethylene, For gas knives such as oxidized carbon or ethanol, the flow rate of the sulphur gas is 1 〇 5 〇 sccm, and the reaction time is 5 minutes to 刈 minutes. Preferably, acetylene is used as the carbon source gas, and the flow rate is 1 〇 25 25 (10) The reaction time is 15 minutes. Referring to Figure 2 and Figure 3, in the preparation process of the branched carbon carbon 16 provided by the present invention, the specific growth process of the branched carbon nanotubes 16 is as follows: The catalyst layer 14 is melted under the action of the temperature of the reaction furnace, The agent layer and the separator 12 are not wetted with each other, and the melted catalyst shrinks into spherical particles and has fluidity on the surface of the separator 12. The carbon source gas decomposes on the surface of the catalyst particles and precipitates carbon atoms, thereby The carbon nanotubes are grown parallel to the direction of the substrate. The catalyst particles are located at the long end of the carbon nanotubes. When the catalyst particles at the top of the growth of the two carbon nanotubes meet, the two smaller catalyst particles can be Combine into a larger catalyst particle j and then grow a new carbon nanotube from the larger catalyst particle, which can be transferred to the Y-type branched carbon nanotube 16 (Fig. 2 (a) and Figure 3 (a) does not. If the growth of the γ-type branched carbon nanotube 16 10 200848541 catalyst particles and another catalyst tube of carbon nanotubes meet, you can get multi-pole Y-type branched carbon nanotubes 16 (as shown in Figure 3 (b)). Similarly, when the catalyst particles of two carbon nanotubes meet head-to-head, they will get the 丄-shaped or ten-type Branched carbon nanotubes 16 (as shown in Figure 3 (c) and Figure 3 (d)), when multiple nanometers When the catalyst particles of the tube meet at the same time, a multi-branched branched carbon nanotube 16 is obtained (as shown in Fig. 3 (e)); when the catalyst particles of one carbon nanotube and the side wall of another carbon nanotube The encounter is known to the L-type branched carbon nanotubes i6 (as shown in Figure 2(b) and Figure 3(f)). The yield of the branched carbon nanotubes prepared by this method is 3〇%~ 5〇%. The branched carbon nanotubes 16 prepared by the method are connected to the electrodes of the electronic circuit by assembly, thereby ensuring good contact between the carbon nanotubes and the circuit. The method prepares the catalyst, so that the grain growth of the branched carbon nanotubes 16 can be realized, which is beneficial to the selective preparation of the carbon nanotube devices. Compared with the prior art, the preparation method of the branched type carbon nanotubes is that the gamma is: (1) decyne, R, and the squamous pure money gas are carbon source pores, which reduces the production cost; (2) preparing the catalyst by the coating method The layer can be used to realize the positioning of the carbon nanotubes. The branched carbon nanotubes are mostly coated with gold, silver and good metals, thus improving the carbon nanotubes and circuits. Electrical connection,, : ^ carbon carbon tube after-stage system; (4) the preparation of the method 1 yield can reach 50% 〇 人 s 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本 本However, the above description is only a preferred embodiment of the present invention, and 11 200848541 can not limit the scope of the present invention. The person who claims the scope of the patent will be assisted by the spirit of the present invention. Inside. DETAILED DESCRIPTION OF THE INVENTION Fig. 1 is a schematic view showing the preparation process of a branched carbon nanotube in the embodiment of the present invention. Fig. 2 is a scanning electron microscope (SEM) photograph of a branched carbon nanotube formed in an example of the present invention. Fig. 3 is a schematic illustration showing the growth process of a branched carbon nanotube in the embodiment of the present invention. [Description of main component symbols] Substrate 10 Isolation layer 12 Catalyst layer 14 Branched carbon nanotubes 16 12