硫族合金奈米複合薄膜於非揮發性浮動閘極記憶體及氫氣感測器之應用研究

Abstract

本計畫擬研究含硫族合金之奈米複合薄膜在化合物在非揮發性浮動閘極記憶體 （Nonvolatile Floating Gate Memory，NFGM）及氫氣感測器之應用。先期研究顯示，以 濺鍍法可製成含硫族合金奈米晶之複合薄膜，其可取代IV 族半導體或過渡金屬之奈米 晶做為NFGM 元件中之電荷捕捉位置，其不僅可降低後熱處理溫度與時間，並可簡化 元件製程與結構；先期研究亦發現硫族合金奈米複合薄膜具備靈敏之氫氣感測性質，其 毋須複雜之化學製程與貴金屬催化物，並可整合於CMOS 製程，這兩項極具潛力之應 用在學理與製程均有許多待釐清與改善之處，故提出本計劃研究之，期能為硫族合金開 啟新穎之應用領域。 本計劃第一年除以先期研究為基礎，完成含硫族合金奈米複合薄膜在 NFGM 元件 應用特性與微觀結構分析，並建立最佳化之元件結構與製程方法之外，並將完成氣體反 應測試系統與即時拉曼光譜儀之建置，以供後續研究分析之用。第二年將以前一年建立 完成之各種硫族合金奈米複合薄膜製成CMOS 結構與商用MOS 感測元件，並完成其氣 體感測能力與反應機制，以奠立硫族合金氣體感測器元件之開發基礎。硫族合金與其奈 米複合薄膜之組成與對不同氣體之感測能力將一併研究之，以完整了解其氣體感測性質 及相關之學理知識。

This project intends to explore the applicability of nanocomposite thin films containing nano-scale chalcogenides to nonvolatile floating gate memory (NFGM) and hydrogen sensor. Preliminary study found that the chalcogenide nanocrystals (NCs) embedded in the matrix of nanocomposite may serve as the charge trapped sites of NFGM devices. In addition to reduce the temperature and time span of post annealing, the utilization of such a nanocomposite may be an alternative to semiconductor and transition metal NCs so as to simplify the NFGM fabrication and device structure. A high sensitivity to hydrogen gas of chalcogenide nanocomposite was also observed in preliminary study. The fabrication of chalcogenide nanocomposite is compatible to present CMOS process and avoid the usage of complicated chemical process and noble-metal catalysts. Since both the fundamental knowledge and applicability of chalcogenide nanocomposite remains to be explored, we hence propose this project in order to implant new application era for chalcogenides. In first year of study, the application properties of chalcogenide nanocomposites to NFGM and relevant microstructure evolution in devices will be investigated on the basis of preliminary study. A gas sensitivity measurement system and a real-time Raman spectroscopy will be also established for subsequent research. In second year, the chalcogenide nanocomposites prepared in first year will be incorporated in CMOS structure to realize its commercial applications. The sensing capability to various types of gases, the effect of constitution of chalcogenides and their nanocomposites to sensing characteristics and the gas reacting mechanisms will also be analyzed so that a full understanding on the gas sensing theories and applicability of chalcogenide nanocomposites can be secured.