有機薄膜式電晶體是相當新穎的電子元件。它有著低成本以及低製程溫度的優點，而這些優點使得它可以選擇不同種類的基板。然而，當有機材料作為半導體使用時，其主要缺點是載子遷移率過低而不敷使用。

　　本論文主要著重於一個叫做氮氣處理的附加步驟。預期此附加步驟將造成一種類似於一般摻雜的效果。隨著此步驟的加入，有機薄膜式電晶體在電特性上將得到更好的表現。

　　第一部分是關於有機薄膜式電晶體隨著氮氣處理的有無，而會有什麼樣的差異性。結果發現經過氮氣處理的元件總是會比未經氮氣處理的元件有著較大的載子遷移率以及較小的臨界電壓。主動層中的載子濃度也在經過氮氣處理之後而有所提升。

　　第二部分主要是關於有機薄膜式電晶體對氮氣處理的時間依存性以及溫度依存性。很明顯的，載子濃度隨著處理時間的延長而增加，但還是有上限。至於溫度，它對有機薄膜式電晶體並無太大改變， 但是元件在140度的溫度之下產生了劣化的現象。

　　最後的實驗中，第一層主動層的厚度被縮減了。我們認為將附加的載子侷限於較薄的主動層中將會對元件的開關控制有所助益。結果顯示，此種結構的元件的確擁有較大的開關電流比以及較佳的表現。

　　綜合上述結論，使用氮氣處理的步驟將有助於有機薄膜式電晶體在特性上的改善。

　Organic thin-film transistors are novel electronic devices. They have the advantages of low cost and low process temperature, and can be fabricated on various substrates deemed possible. However, the carrier mobility of organic material is still relatively poor when it is used as semiconductor.

　This thesis will focus on the additional process called N2 treatment. This treatment is similar to general doping process. With the treatment, the OTFTs can get better performance in electrical characteristics.

　The first part is concerned with the difference in performance between OTFTs fabricated with and without N2 treatment. The devices with N2 treatment always have larger mobility and smaller threshold voltage than those without N2 treatment. Furthermore, the carrier concentration was found to increase in active layer after N2 treatment.

　The second part is mainly devoted to the studies of time-dependence and temperature-dependence of OTFTs with N2 treatment. Obviously, to a limited extent the carrier concentration increases with the treatment time. As for the temperature, On the contrary, the temperature virtually has no influence on improving OTFTs but instead causing degradation of devices at 140°C.

　At last experiment the thickness of first active layer was decreased. The confinement of additional carriers in a thinner active layer should prove helpful in terms of switching OTFTs. The results have demonstrated that the device with this structure does have larger on/off current ratio and better performance.

　In conclusion, the improvement in performance of OTFTs can be achieved via N2 treatment.

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