以 SiO2 為氧化層的 MOS 結構因容易備製與良好的絕緣性，在早期備受關注。而鋁金屬是高導熱與高導電的材料之一，這類金屬薄膜的外延生長是廣泛應用於電子元件中電氣觸點 ( Electrical Contacts ) 與連接 ( Interconnections ) 的技術。此外也有學者提出在半導體與金屬之間嵌入一層極薄的絕緣層，可以減緩費米能階釘扎效應與降低蕭特基能障。因此若能了解這類薄膜的生長特性，便有助於更好的應用。
在2004年有兩篇報告，觀察了在室溫以及低溫 (145 K)中鋁在矽(111)上的薄膜成長，透過在不同溫度下蒸鍍少量的鋁，再退火後使用反射式高能電子衍射儀 ( RHEED ) 以及掃描穿隧顯微镜( STM ) 觀察表面狀態，除了觀察因應晶格不匹配而有特殊生長模式外，在發現特定條件下有機會生長出平坦的表面，這對製造量子元件是重要的技術。而我們以此為出發點，透過曝氧改變矽(111)表面的狀態，觀察氧對鋁薄膜的影響。
本實驗全程於超高真空中進行，將乾淨的矽(111)基板加熱至 300 ℃，並曝上適量的氧，使其形成氧化矽薄膜，待降回室溫後，蒸鍍鋁並進行退火，便會形成鋁箔膜。實驗結果主要以STM進行結果的量測。STM有著近 0.01 nm 的空間解析度，可以在不破壞樣品的狀況下觀察到原子在實空間的排列，並在後續進行傅立葉轉換的倒晶格分析及STS頻譜分析，進而分辨表面樣貌。
結果上觀察到氧會減弱矽上懸空鍵對鋁的作用，並在退火過程中脫離矽的吸附，轉移至鋁箔膜的表層。氧的介入加速原子在表面移動現象，並影響島嶼生長的形式。本實驗探討鋁在氧化矽的生長過程，並統整氧在矽與鋁之間的作用，相信對於理解材料的特性，與MOS系統的製成提供了一種新的思維與方向。

The MOS structure with SiO2 as oxide layer has obtained a lot of attention because of its easy preparation and great electrical insulation. Aluminum is a material with high thermal conductivity and high electrical conductivity. The epitaxial growth of this kind of metallic film is widely used as electrical contacts and interconnections in very large scale integrated electronics. Some researchers have proposed to embed a very thin insulating layer between the semiconductor and the metal, which can slow down the Fermi level pinning effect and reduce the Schottky energy barrier. Therefore, understanding the growth characteristics of this type of film can help better performance in applications.
In 2004, two reports observed the growth of Al/Si(111) at room temperature and low temperature (145 K) , they deposited Al at different temperatures and observed the surface with reflection high energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). In addition to observing the special growth mode due to lattice mismatch, a flat Al film can be grown under certain conditions. It is an important technology for manufacturing quantum components. We use this as a starting point to change the state of the Si(111) surface through oxygen exposure to observe the effect of oxide on the growth of aluminum films.
The whole experiment was carried out in an ultra-high vacuum chamber. The clean Si(111) substrate was heated to 300 ℃ and exposed oxygen to form a silicon oxide film. After cooling to room temperature, aluminum was deposited and annealed to 250 ~ 300 ℃, an aluminum film is obtained. The experimental results are measured by STM. With an ultra-high resolution of close to 0.01 nm the arrangement of atoms in real space can be observed without damaging the sample. The inverted lattice analysis of Fourier transform and STS spectrum analysis was performed to distinguish the surface periodicity.
Our results indicate that the SiOx layer weakens the effect of silicon adatom. Oxygen will be released from the SiOx layer during the annealing process and moved to the surface of the aluminum film. The intervention of oxygen accelerates the movement of atoms on the surface and affects the formation of island growth. This experiment explores the growth process of aluminum on silicon oxide and clarifies the role of oxygen between silicon and aluminum. This investigation provides a new direction for understanding the characteristics of materials and the fabrication and morphology of the Al films.

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