| Summary: | 碩士 === 臺灣大學 === 應用力學研究所 === 98 === 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.
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