表面電漿子，產生於金屬和介電質介面的現象，由於能克服光學繞射極限，使人們利用此技術能操縱遠小於光學波長的尺度。基於成長、製作奈米元件的能力逐漸成熟，不管是在材料上、尺度上，都已有許多突破性的進展，而成長超薄膜材料的一大優勢為可調控其表面電漿共振位置。在材料的選擇上，鋁，相較於金、銀等傳統電漿材料，不需要成長額外的緩衝層，此優勢可令其在製程上更簡單，物理模型也更單純，如此能更凸顯其應用在超薄膜的價值，是一個可嘗試作為替代貴金屬的電漿材料。
本論文以熱蒸鍍(Thermal Evaporator)方法在c面藍寶石基板上成長出高品質的單晶超薄鋁，透過原子力顯微鏡(AFM)確認表面為原子級平整，高解析穿透式電子顯微鏡(HRTEM)確認樣品為連續膜，再利用高解析X光繞射儀(HRXRD)擬合其厚度，確認生長的出薄膜鋁具有良好的晶向及表面形貌。透過橢圓偏光儀(SE)量測超薄鋁膜，擬合出薄膜介電函數，並計算出4、6、8、10、30.5nm鋁的品質因子在400-700nm的波段為150-300，確保鋁的表面電漿應用範圍可以包含到可見光區。使用聚焦離子束(FIB)製程在超薄鋁上做出奈米溝槽結構，透過白光干涉(WLI)量測表面電漿子，並以橢圓偏光儀擬合出的介電函數利用FDTD進行模擬，將白光干涉及橢圓偏光儀兩者實驗的結果畫出色散圖後進行比較，可得到穩合的結果。從色散圖得知15nm以下可產生明顯的超薄膜效應，10nm以下能成功激發出超薄膜效應下的對稱模態，此模態將能大幅調控其表面電漿共振波段。

Surface plasmons, the phenomenon that occurs at the interface of metal and dielectric, overcome the optical diffraction limit, allowing people to use this technique to manipulate subwavelength scales. Based on the progress of growing and fabricating nanodevices, there are many breakthroughs in materials and scales, and one of the major advantages of growing ultrathin film materials is that the tunability of surface plasmon resonance. In terms of material selection, compared with gold and silver, aluminum does not need to grow an additional buffer layer. This advantage can make it simpler in the process and the physical model, which can further highlight its application in ultrathin films. The thesis is trying to show that aluminum is an alternative plasmonic material to silver and gold and demonstrate its ultrathin film properties.
In this thesis, high-quality single crystalline ultrathin aluminum films are grown on the c-plane sapphire substrate by thermal evaporator. The surface morphology is confirmed to be atomically smooth by atomic force microscopy (AFM), and a continuous film by high resolution transmission electron microscopy (HRTEM). Then, the thickness is investigated by high resolution X-ray diffractometer (HRXRD). Using spectroscopic ellipsometry (SE) to measure ultrathin aluminum films and fit its dielectric function, then the quality factor of 4, 6, 8, 10, and 30.5 nm aluminum films are calculated to be 150-300 in 400-700nm range, which ensures that the application range of aluminum surface plasmon can cover the full visible range. In the fabrication process, nanoslit arrays are fabricated by Focused Ion Beam (FIB), and the surface plasmons is measured by white light interferometry (WLI). Finally, compare the result of WLI, and the FDTD simulation, which dielectric function is fitted by the ellipsometry. After comparison, the consistent result can be obtained. It can be seen from the dispersion diagram that the ultrathin film effect occurs below 15 nm, and the symmetric mode of the ultrathin film effect can be successfully excited below 10 nm, which can greatly control the surface plasmon resonance.

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