近年來，對於多鐵性材料的研究開始在學術界引起一股風潮。因為多鐵性材料本身特殊性質，讓我們有了製作新穎的電子元件的契機，但可惜的是，許多的多鐵材料在室溫下都將失去其多鐵性。而本論文所利用的材料鉍鐵氧(BiFeO3)，不論是居禮溫度或著是尼爾溫度都是高於室溫的，這樣的特色使得鉍鐵氧在許多的多鐵材料中脫穎而出，成為最有希望的先進材料。

但可惜的是，由於鉍鐵氧本身的能隙過大，致使雖然具有優秀的室溫多鐵性，但卻因為其導電性極差，所以極難應用在電子元件中。此時，存在於鉍鐵氧材料上的疇區壁，給予了鉍鐵氧材料一個走上真正應用道路的機會。因為不論在理論上，或著是實驗中，都已證明了疇區壁可以有效的提升鉍鐵氧薄膜的導電性。正因為如此，本論文希望利用存在鉍鐵氧薄膜上疇區壁的特性，加以分析希望最終可以利用"場效"來調控甚至開關疇區壁上的電流。

而本論文前兩章，將會藉由文獻回顧的方式。除了介紹鉍鐵氧這樣特殊的多鐵特性外，也會在過程中將疇區壁的重要性以及特色點出。而第三章將介紹如何利用脈衝雷射沉積法來製備我們所使用的鉍鐵氧薄膜，也會將如何利用探針技術來定義疇區壁的特性以及品質的方法做一個簡單的介紹。最後第四章以及第五章除了將我們如何製備元件的方法詳細敘述外，也將會揭露疇區壁上的傳輸特性以及詳細介紹所製作的電晶體的電性以及分析。

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