製備周期性奈米結構銳鈦礦二氧化鈦薄膜之研究

Abstract

摘要 在本研究中，提出藉由膠體粒子的自組裝性質結合蝕刻技術，製作出大面積、有周期性柱狀奈米結構的二氧化鈦薄膜。且此周期性結構可透過選擇不同大小尺寸的膠體粒子做為光罩來控制其間隔，而柱狀結構的高寬可透過氧電漿及四氟化碳電漿反應離子蝕刻的參數加以調整。而有著周期性柱狀奈米結構的二氧化鈦薄膜則有望應用於有機太陽能電池的系統，提供一個直接傳導電子的通路。我們藉由使用功率較高的耦合式反應離子蝕刻技術成功地製作出具有高約為70∼130奈米，直徑約為160奈米，間距約為120奈米周期性結構的二氧化鈦薄膜及高約為85∼125奈米，直徑約為135奈米，間距約為145奈米周期性結構的二氧化鈦薄膜。若可有效控制蝕刻時的溫度，則有望製作出高寬比更大的柱狀結構。

Abstract During the last two decades, nanostructured materials have attracted much attentions because of their massive possible abilities. For the most widely used conventional photolithography, diffraction limits its’ resolution to ~100nm. For electron beam lithography(EBL) and focus ion beam(FIB), extremely high resolution can be achieved, however, high cost and low throughput limited further application for these two technique. Thus, fabrication of large area nanostructure materials is still a huge challenge. In this study, we offer an alternative approach to fabricate large area ordered nanostructures on TiO2 film, which has never done before. We applied nanosphere lithography(NSL), which is not limited by light diffraction and cost. NSL takes the advantage of the self assembly nature of nanospheres, and thus allow to form large periodic nanostructures rapidly and easily. More further, the self assembled nanosphere monolayer can be modified with reactive ion etching(RIE) technique. The modified sphere monolayer can act as mask for either deposition or etching process, thus various nanostructures can be made by this method. The periodical structure can be controlled by using different sizes of polystyrene spheres and more precise control can be achieved by oxygen plasma to modify the sphere mask. The column structure is likely to provide a good electron transportation path, thus to achieve a better efficiency. Nano column structure with height 70~130，diameter 135~160nm can be made on anatase TiO2 films. Better process temperature control is crucial for higher aspect ratio.