非晶矽薄膜電晶體已經被廣泛的應用，像是液晶顯示器(LCD)、固態X-ray或是近來的有機發光二極體(OLED)等等。非晶矽薄膜電晶體可以利用較低的成本製作在大面板尺寸上面，其可複製的元件特性也能適用在其他一些應用上。這點讓非晶矽薄膜電晶體的技術變得很有吸引性。但是將非晶矽薄膜電晶體應用在畫素的驅動元件時，其較低的電子遷移率和在偏壓下所導致的電性變差使其受到使用上的限制。另一方面，微晶矽薄膜電晶體因為它可像非晶矽般在大尺寸面板上應用，近年來被認為是一個有潛力的選擇。
然而，研究微晶矽薄膜電晶體的人普遍都會遇到同樣的問題，那就是其漏電流過高的情況。過高的漏電流，對於應用在主動式有機發光二極體(AMOLED)的開關元件上面是會產生問題的。在這篇論文裡面，我們會把焦點放在微晶矽薄膜電晶體的漏電機制上面。
在這裡，我們成功地利用電漿輔助化學氣相沉積去製作微晶矽薄膜。之後透過電漿在閘極絕緣層的處理，我們可以成長一個結晶度很高的微晶矽薄膜。而且我們對微晶矽薄膜電晶體的漏電機制做了一個探討，並且找到了一個方法可以去抑制它的漏電流。最後我們拿感應耦合電漿化學氣相沉積(ICP-CVD)的微晶矽和電漿輔助化學氣相沉積(PECVD)的微晶矽做比較。可以觀察到兩者之間會有不同的特性展現。

Hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs) are widely used in active matrix flat panel electronics such as liquid crystal displays (LCDs), solid-state X-ray imagers, and more recently, organic light emitting displays (OLEDs). With a-Si:H TFTs, reproducible device characteristics that suit a number of applications can be obtained over a large substrate area using a simple low cost fabrication process. This makes a-Si:H TFT technology very attractive. However, low field effect mobility and electrical degradation restrict the use of a-Si:H TFTs as pixel drivers. On the other hand, hydrogenated microcrystalline silicon (μc-Si:H) has recently received considerable attention as a viable alternative to its amorphous counterpart for large-area applications.
However, people studying on microcrystalline silicon TFTs will encounter an issue that the leakage current of TFTs is about 100pA which is a very high value if to be used as a switching TFT for AMOLED display. In this present thesis, we focus on the mechanism of the leakage current in microcrystalline TFTs.
In our work, we use plasma enhanced chemical vapor deposition (PECVD) to fabricate deposition of microcrystalline silicon (uc-Si) film successfully. Through plasma treatment at surface of gate dielectric, we has grown the uc-Si with high crystallization. And we investigate the mechanism of leakage current in uc-Si TFTs and find a way to suppress that. Finally, we compare with uc-Si deposited by ICP-CVD. And the different characteristics of uc-Si TFTs was observed between the ICP-CVD and PECVD.

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