高介電值閘極介電層低溫製程薄膜電晶體的研究與開發

Low-temperature Fabrication Process for High-K Gate Dielectrics Thin Film Transistors

賴柏誠(Po-Cheng Lai)

指導教授 ： 李世光

共同指導教授 ： 林世明

國立臺灣大學/工學院/應用力學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.10674

摘要

過去薄膜電晶體的製程複雜、手續繁瑣，常常需要在高潔淨度之無塵室中製作，導致製作成本十分的高昂。本論文以設計開發出可以在室溫下進行製作為目標，並朝大面積、可撓曲的方向前進。
　　首先，先利用鍍膜技術，從高介電值之金屬鋁、鈦、鉭等金屬做為電晶體的閘極，再藉由簡易的電化學、酸鹼反應、氧化還原、電漿反應等常溫下可以操作的方式，來使上述金屬產生不導電的氧化物，進而達到在閘極上直接產生高介電係數閘極介電層。接著，再以奈米碳管和溶膠凝膠法之氧化鋅分別作為薄膜電晶體之主動層，同時也達成低溫製程的目的。
　　完成上述步驟後，薄膜電晶體元件就大功告成。再以探針台量測所製作出的薄膜電晶體之載子遷移率、閘極電壓對汲極電流的關係和元件開關比等元件之參數，來驗證所製作之元件可達應用程度。
　　未來可嘗試將原本矽晶圓的基板改以塑膠基板來代替，並將尋找透明之電極材料取代金屬電極，來重複上述之薄膜電晶體之製作過程，以祈能提升整體薄膜電晶體之透明度和可撓曲度，使元件能更臻完美。

關鍵字

高介電值 ； 金屬閘極 ； 低溫製程 ； 奈米碳管 ； 氧化鋅 ； 薄膜電晶體

並列摘要

A newly developed process for making high-K dielectric thin film transistors is presented. Starting from a Silicon substrate, high-K materials such as Aluminum, Titanium and Tantalum were coated to form the metal gate. As these three chosen materials can be easily oxidized, the gate insulator on top of the metal gate can thus be fabricated by oxidization, electroplating, wet chemical process, high-temperature furnace oxidization, or even oxygen plasma in room temperate. This process naturally leads to small gate thickness. Furthermore, Aluminum oxides, Titanium oxides and Tantalum oxides have high enough dielectric constant, band gap and have good contact to the original metal gate when compared to many other materials. When compared to previous processes based on using chemical vapor deposition (CVD) to deposit SiO2, SiNX or some low-K materials to make the gate insulator, the above-mentioned process fabricated the gate and the gate insulator (Aluminum oxide, Titanium oxide and Tantalum oxide) thin film without the need to deposit the insulator layer separately. It is to be noted that this process contains only low temperature processes after the metal gate is deposited, which means that this process can be used for flexible electronics once the substrate is changed from silicon to flexible substrate.

並列關鍵字

High-K ； High-K dielectric ； metal gate ； low temperature fabrication ； thin film transistor

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