| 摘要: | 目前運用化學氣相沉積法在金屬基板(如銅、鎳)上合成大面積石墨烯雖然是非常成熟的技術，但是目前仍然無法直接將合成在金屬催化基板上的石墨烯直接應用於各式元件中；因此需要藉由轉印技術來將石墨烯從金屬基板轉移到其他目標基板上。雖然已經有各種不同方法被提出，但是在轉印的過程中仍然會造成破壞、汙染甚至是高分子的殘留，進而影響石墨烯本身的材料特性。因此如何減少轉印過程中的破壞以及降低缺陷的形成，並得到大面積潔淨石墨烯薄膜，是目前石墨烯應用上首要解決的難題。
本實驗將以紫外光解黏膠帶取代捲對捲乾式轉印中常用的熱解黏膠帶作為支撐層；並且使用更容易去除的高分子Rosin作為緩衝層來降低轉印過程中造成的缺陷和殘留。其中具體研究成果：(1)使用紫外光解黏膠帶轉印的石墨烯表面潔淨度達99.1 %且載子遷移率為1105 cm2/Vs，比傳統濕式轉印高約1.6倍，也比TRT乾式轉印高約1.1倍。(2)紫外光解黏膠帶的脫附機制，不必經過繁雜的曝光顯影步驟，讓石墨烯可在脫離光解黏膠帶時同步選擇性圖案化，最小線寬約100 μm，並用於後續元件製作。此外，在實驗過程中發現紫外光能使緩衝層- Rosin劣化讓它從長鏈的聚合物分解成短分子，而當Rosin分子之間的鍵結被打斷後，有利於在有機溶劑清洗時，讓Rosin變得更加容易被去除，並且基於Rosin裂解的機制，將Rosin照射紫外光後再放置於潮濕環境中，也發現能加快Rosin劣化。對TRT乾式轉印的石墨烯表面進行紫外光與潮濕環境的處理與未經任何處理的比較，其潔淨度高達99.4 %且載子遷移率升高1.3倍，此實驗發現更有效去除Rosin且不會對石墨烯造成缺陷的方法，本研究提供一個同時圖案化且高品質石墨烯轉印的策略，有助於未來石墨烯於多樣化之功能性元件的應用。
;Currently, the synthesis of large-area graphene on metal substrates (such as copper and nickel) by chemical vapor deposition method is a mature technology; however, it is still challenging to directly apply graphene, synthesized on catalytic substrates, to various components. Therefore, it is necessary to transfer graphene from the metal substrate to target substrates. Although various methods have been proposed, the transfer process will still cause the defeat, pollution and even polymer residues, which will affect the material properties of pristine graphene. Therefore, how to reduce the damage during the transfer process and avoid the formation of defects for obtaining a large-area clean graphene film, is the main issue required to be addressed before it been used in various applications.
In this work, we proposed the ultraviolet light release tape as the support layer for replacing the frequently used thermal release tape in a typical roll-to-roll dry transferring process; and use the easier-to-remove polymer Rosin as a buffer layer to reduce the defects that occur during the transfer process. The specific research results: (1) The surface cleanliness of graphene transferred by ultraviolet light release tape is 99 % and the mobility is 1105 cm2/Vs, which is about 1.6 times higher than that of general wet transfer and is also about 1.1 times higher than TRT transfer. (2) The UV illumination lead to the facile release of graphene film which is beneficial to achieving one-step and selective patterning of graphene go without the complicated procedure, with a minimum width of about 100 μm and feasible for the subsequent component integration. Moreover, it was found that UV light can degrade the buffer layer-Rosin, which decomposes rosin from long-chain polymers into short molecules. When the bond between the rosin molecules is broken, it is beneficial for obtaining the cleaning graphene surface. Based on the mechanism of Rosin dissociation, the Rosin is irradiated with ultraviolet light followed by facilitated degradation under a humid environment. The graphene of TRT transfer printing is treated with ultraviolet light and humid environment compared with the graphene of pristine TRT transfer, the cleanliness is 99.4 % and the carrier mobility is increased by 1.3 times. The method found that the Rosin is more effectively removed and that does not cause defects in graphene. This proposed transferring method enables the facile patterning together with maintaining the high-quality graphene film, which paves the way to versatile functional graphene applications. |
