近來年，由於鉍的原子量較大帶有非常強的自旋霍爾效應，因此利用多層膜製備的鉍薄膜在自旋軌道扭矩裝置中具有很大的吸引力。我們的主要目標是如何製備出具有平滑表面的鉍薄膜，可以應用於改善自旋流轉換電荷流的效率。在我們的實驗中，我們使用直流和交流濺射在玻璃基板上生長鉍薄膜，並比較這兩種不同沉積技術的表面形貌變化。 X射線反射率用於量測出薄膜的粗糙度，厚度和電子密度。我們通過掃描式電子顯微鏡和X射線繞射來比較表面形貌和晶體性質。在實驗分析結果中，我們發現，在相同厚度下(12 ± 1 nm)，直流濺鍍之鉍和氧化鉍的界面粗糙度為9.5 ± 4 Å而交流濺鍍為48.9 ± 8.5 Å，可能是因為原子敲擊效應和薄膜表面的大晶粒造成。我們也利用了X光吸收光譜證實非晶碳膜(厚度約為10 nm)之覆蓋層在長時間內並無法保護鉍薄膜不被氧化。從XRD結果，我們觀察到不同濺鍍方式之鉍薄膜有不同的優選取向，直流濺鍍和交流濺鍍分別為(003)和(012)方向，有可能是因為交流濺鍍之沉積速率較慢，吸附原子在薄膜表面有足夠的能量和時間有利於形成Bi(012)晶面，雙層與雙層之間鉍原子的鍵結較為穩定。而與之相反，直流濺射之沉積速率較快，吸附原子不利於形成(012)晶面，鉍原子與雙層內的三個最相鄰近原子形成穩定的鍵結，因此較有利於(003)方向的生長。

Recently, preparation of bismuth thin film is attractive in fabricating the spin-orbital torque device because of strongly spin Hall effect, using multilayer deposition method. How to make a thin bismuth thin film with smooth surface for spin-orbital torque device production is our main goal. In our work, we deposited bismuth thin film on glass substrate by DC and RF sputtering deposition and to compare the surface morphology change. X-ray reflectivity is used to examine the thin film roughness, thickness and electron density. We measured surface morphology and crystal properties by scanning electron spectroscopy and X-ray diffraction. In the experiment analysis result, we found that bismuth thin films deposited by DC sputtering deposition is smoother than that deposited by RF sputtering deposition in the same thickness because of the atomic peening effect and large grain on the surface of thin films. We confirm oxidation of top layer of bismuth from the energy shift of X-ray absorption spectroscopy in bismuth thin films coating with only 9 nanometer carbon layer. From the XRD result, we also found that the preferred orientation is (012) deposited by RF sputtering deposition and the preferred orientation is (003) by DC sputtering deposition. The different energy of sputtered Bi atoms by DC and RF magnetron sputtering methods might cause these subtle morphology difference.

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