低溫下利用大氣電漿沉積二氧化矽薄膜作為有機薄膜電晶體之閘極絕緣層在不同基本製程參數之研究

Abstract

我們成功地在低製程溫度下製作低操作電壓頂部接觸之汲極與源極結構的有機薄膜電晶體，且利用大氣電漿技術在基板溫150℃和大氣壓下成長閘極介電層，在這樣的製程環境可以改善大面積的製程能力以利於應用在顯示器上並且減少設備的費用，我們發現大氣電漿沉積的矽氧化物的品質強烈取決於主要氣體、設備的電漿噴嘴和表面之間的距離與氬氣的流量，而這些因素甚至也影響沉積速率。我們藉由改善閘極絕緣層的特性可使得有機薄膜電晶體可以得到良好的電性，其載子遷移率達到0.66 cm2/ V•s、操作電壓約在-2 V、次臨界擺幅約0.7 V/dec。

Low operation voltage organic thin film transistors (OTFTs) were successfully fabricated with top contact structure at low fabrication temperature. The thin gate dielectric of OTFTs were deposited by atmospheric pressure plasma jet at the substrate temperature about 150℃and under atmospheric pressure. The environment of processes would significantly improve the abilities of large area application for display and decrease the cost of instruments. We found that the quality of silicon oxide deposited by atmospheric pressure plasma jet strongly depended on the main gas, the gap distance between plasma nozzle and surface of the device, and the Ar flow rate even influenced the deposition rate. Due to the improvement of gate insulator quality, good electrical characteristics of OTFTs can be obtained, such as carrier mobility as large as 0.66 cm2/ V•s, operation voltage as low as -2 V, and subthreshold swing as low as 0.7 V/dec.