一般來說，金屬矽化物與純金屬比較，具有較好的熱穩定性和不容易被氧化的特性，且有較佳的抗腐蝕能力；大部分的金屬氧化物相對於金屬也具有較低的電阻。所以金屬矽化物也是第一個被用在 MOS 結構中的閘極（gate）、ohmic contacts 和 Scotty barriers 的材料。
從 Fe-Si 的相圖中，在相圖兩側分別表示金屬含量比較高和 Si 含量比較高的區域，各別具有許多不同的相，顯示了 Fe、Si 系統在不同成分比例組成下的複雜性，例如 Fe3Si, FeSi2、Fe5Si3、FeSi…等；另一方面，即使具有相同的定量組成，也有可能因為其晶格或是電子結構的不同，使其具有不同的性質。
雖然到目前為止，矽化鐵奈米結構的生成機制尚不明朗，但是有不同的報告指出在謹慎小心的控制溫度、壓力、載流氣體流量等基本參數，可以利用 CVD 合成出形貌為一維的奈米線或是奈米螺旋狀結構。
我們注意到 beta-FeSi2 相較其他矽化物具有獨特的性質。根據理論計算和實驗數據都顯示 beta-FeSi2 對光有較高的吸收係數且較小的能階，其能階約為 0.85 eV，而 0.85 eV 對應到光波的波長為 1.5 μm。因此我們可以將 beta-FeSi2 與其他具有不同能階的矽化物合成在同一個 Si 晶片上，應用到許多不同的領域，例如紅外光偵測器、光電元件。
在本研究中，beta-FeSi2 奈米線是經由化學氣相沈積法（Chemical Vapor Deposition）來合成。在 700 ~ 900 ℃ 的溫度範圍間，經由載流氣體（carrier gas）將 FeCl3 前驅物運送到 Si 基板處反應生成 β 相的 FeSi2 ， beta-FeSi2 的結構可以經由 XRD 和 TEM 的分析交互比對來獲得證實，且其結構的形貌也可經由 SEM 直接觀測。綜合以上分析，在 700 ~ 900 ℃ 的溫度之間 我們找到一個穩定的方法來合成 beta-FeSi2 奈米線。

In this study, FeSi nanowires were fabricated by chemical vapor deposition method. Beta-FeSi2 nanowires were deposited on Si substrate by applying FeCl3 as precursor at temperature ranged from 700 to 900 ℃. The structure of beta-FeSi2 nanowire was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The surface morphology were analyzed by scanning electron microscopy (SEM). This study provide a stable and catalyst-free procedure for beta-FeSi2 nanowire at temperature ranged from 700 to 900 ℃.
Metal Silicides are characterized by their high thermal stability and better resistance against oxidation than pure metals. Most of them are metallic and have low resistivity. Exactly metallic silicides were first employed for interconnections, gate in MOS structures, ohmic contacts, and Scotty barriers.
From the Fe-Si phase diagram, numerous specific phase has been identified in both metal-rich and silicon-rich regions. They clearly demonstrate which definitely shows the complexity of the system with different chemical compositions such as Fe3Si, FeSi2, Fe5Si3, FeSi…etc. In addition, even with the same stoichiometry samples might possess diverse properties due to their lattice and electronic structure.
Even if the growth mechanism is not yet fully recognized, it was reported that morphology of one dimension FeSi nanowires [1] and FeSi spiral structure [2] could be acquired by chemical vapor deposition (CVD) under certain condition with careful control of temperature, pressure and the flow rate of carrier gas.
The fantastic features of beta-FeSi2 were thoroughly investigated. The theoretical prediction and experimental results show that beta-FeSi2 has a high optical coefficient as well as a direct band gap of ~ 0.85 eV [3] , which corresponding to the optical wavelength of 1.5 μm. As a result, we can mixing beta-FeSi2 with other silicides with various gaps integrated on a single silicon chip and offers potential applications in areas, such as infrared light detectors, opto-electric devices, and photovoltaics.

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