石墨烯場效電晶體常因基板上電荷散射、雜質及殘留等因素，影響元件的電子性能，因此有研究提出了懸空石墨烯元件，將石墨烯做成懸空結構能避免基板因素的影響，保持石墨烯最本質的性質，但由於懸空石墨烯元件所能製作元件尺寸小且製程困難，所以本實驗選擇使用自組裝膜的方式製作場效電晶體元件，達到類懸空結構的效果，同樣能改善石墨烯元件之電性。 本研究之具體成果：(1)使用熱蒸鍍法改質基板，水接觸角從34.36°提升至115.26°。 (2)改質基板轉印石墨烯，石墨烯並不會與氟原子產生額外鍵結，因此並不會影響石墨烯品質。 (3)自組裝膜無法改善基板的表面粗糙度，改質基板比未改質基板表面粗糙度上升2.09 nm，證明基板表面粗糙度並非載子遷移率增加的主因。 (4)以改質基板搭配高分子轉印石墨烯，有助於電性提升，濕式轉印的電子和電洞遷移率可提升6.42 %和29.65 %，乾式轉印的電子及電洞遷移率可達296.32 %和300.00 %。 (5)使用直接轉印(Drc-FS)的方式，可以於不破壞石墨烯晶格結構的情形下提升效能，與一般常見的濕轉相比，其電子遷移率提高600.23 %，電洞遷移率提高713.01 %。 ;Graphene field-effect transistors often affect the electronic properties, because of charge scattering, impurities, and residues on the substrate. Therefore, research has proposed the suspended graphene device, the suspended structure to avoid the influence of substrate factors. The essential properties of graphene are maintained. However, the suspended graphene device can be made with small size and difficult processes, this experiment chooses to use a self-assembled film to make a device. The half suspended structure can improve the electrical properties of the graphene device. Results of this research are as follows. (1) This experiment uses thermal evaporation to the modified substrate, the contact angle 34.36° increase to 115.26°. (2) Using modified substrate transfer graphene, the graphene does not have bonding with the fluorine atom, and it does not affect the graphene quality. (3) The surface roughness of the modified substrate is 2.09 nm higher than the unmodified substrate. Therefore, the increased mobility is not mainly related to the roughness of the substrate. (4) Using the polymer transfer graphene on the modified substrate, which contributes to electrical improvement. Electron mobility and hole mobility of the wet transfer can be increased by 6.42% and 29.65%. Electron mobility and hole mobility of the dry transfer can be increased by 296.32% and 300.00%. (5) Using direct transfer (Drc-FS), the F-SAM can successfully increase mobility without alter the graphene lattice. Compared with the common wet transfer, the electron mobility is increased by 600.23 % and the hole mobility is increased by 713.01 %.
