利用噴墨技術在塑膠基板上製作有機薄膜電晶體

Abstract

以有機化合物或是高分子材料在塑膠基材上製作電子電路，一直是非常重要的研究主題。在塑膠基板，以有機化合物或是高分子材料作為電晶體元件就可以非常便宜的噴墨(inkjet printing)方式大量生產大幅降低成本，而以噴墨製程製作電子原件最大的好處是設備簡單，不需要光罩或是母模，但是其缺點是解析度較差。2000年劍橋大學首先發表以改變基材上親疏水性，來改善噴墨系統的精準度問題，該此技術可製作閘極寬度僅5μm的全噴墨製程有機薄膜電晶體，而後陸續幾年內仍以噴墨技術為發展方向，在有機薄膜電晶體上仍有創新突破。 本論文研究方向，首先架設出整體之實驗流程架構裝置，再以文獻研究為基礎，希望能夠達成用噴墨製作在塑膠基板上製作全有機之薄膜電晶體。目前以PMMA作為絕緣層，P3HT為半導體層以及PEDOT/PSS作為電極，在透明塑膠片上成功的滴鑄出全有機的元件，同時無漏電流現象發生；但元件閘極電壓對通道的控制能力相當薄弱，將來會進一步改進。

Research into organic thin film transistor (OTFT) has been rapidly growing in the past few years. The use of organic semiconductor devices promises low-cost electronics over large area, using solution based deposition techniques under ambient condition. By direct printing of solution process materials provide a new route to the fabrication of organic thin film transistors. Although the natural resolution with inkjet printing system is limited, the resolution of critical dimension can be improved by surface energy patterns causing inks to be repelled and dewetting form pre-defined regions on substrate. With this technique, the critical channel length dimensions can be lowered down to sub-micrometer range. Printing sub-micron electrode spacing for organic transistors is an important step towards high performance low-cost organic plastronics. More studies will be needed to achieve the reproducibility and process stability toward this goal. The OTFT process mentioned was fabricated on glass or silicon wafer with one lithography step on patterning the channel region. Here, a new process based on hot-embossed nano-imprint was proposed to eliminate the lithography step, and the processing temperature through the whole process is confined below the temperature plastic substrates can sustained.