- 學位論文
不同濃度 RCA 溶液表面處理的 ITO 基板上Pentacene 薄膜結構與界面電性研究
The Structure and Interface Electrical Properties of Pentacene Thin Film on ITO Substrate Depending on ITO Surface Processing of Different Concentration RCA Solution
摘要
本論文探討銦錫氧化物(ITO)薄膜經由不同濃度RCA溶液處理過後之電性變化。實驗中利用不同氨水及雙氧水濃度之RCA溶液處理ITO薄膜表面，再將ITO表面蒸鍍Pentacene有機半導體材料，ITO與Pentacene接觸形成歐姆接觸，再經由傳輸線模型(TLM)、接觸角量測(Contact angle )、原子力顯微鏡(AFM)、光電子能譜儀(UPS/XPS)、光電子繞射儀(XRD)進行研究分析。 根據實驗結果發現，經由不同濃雙氧水濃度之RCA溶液處理ITO薄膜後，所成長出的Pentacene薄膜中摻雜了Single crystal phase、bulk phase。ITO薄膜無表面處理時特徵電阻值為7.61×10^5(Ω-cm^2)，經由雙氧水25%之RCA溶液處理後有最低的特徵電阻值2.50×10^5(Ω-cm^2)。另外，經由不同濃度處理過後之ITO功函數確實有不同變化，在雙氧水濃度為14%時有最大功函數5.03eV，證實ITO經由 RCA 溶液處理過後,ITO表面同時達到清潔及功函數提高的效果。經由不同量測所得之結果比較(傳輸線模型(TLM)---片電阻、XPS—束縛能、UPS---功函數)，我們也發現銦元素的束縛能變化與ITO的功函數相關，當銦元素的束縛能較低時ITO薄膜具有較高的功函數，也同時在ITO/Pentacene接觸上具有較低的接觸電阻。
並列摘要
In this thesis, we study the structure and interface electrical properties of Pentacene thin film on ITO substrate, the ITO surface is cleaned by different concentration RCA solution. The study method is using RCA solution of different ammonia and hydrogen peroxide concentrations to treat ITO film surface, then coating Pentacene thin film on ITO substrate. In order to make Pentacene and ITO forming ohmic contact. Via the transmission line model (TLM), contact angle measurements (Contact angle), atomic force microscopy (AFM), photoelectron spectroscopy (UPS / XPS) and photoelectron diffraction (XRD), we can understand the interface properties between Pentacene and ITO. According to the experimental results, using RCA solution of different hydrogen peroxide concentrations to treat ITO film surface, the Pentacene films composed of single crystal phase and bulk phase. The characteristic resistance of ITO film without surface treatment is 7.61×10^5 (Ω-cm^2), via RCA 25% hydrogen peroxide solution’s treatment, we get the lowest characteristic resistance value : 2.50×10^5 (Ω-cm^2). In addition, after processing of RCA solution, the work functions of ITO films have different variations. The maximum work function is 5.03eV from the treatment condition of the 14% concentration hydrogen peroxide RCA solution. Confirmed that ITO film surface will be cleaned and its work function will be improved after RCA solution treatment. Via different measurement results (Transmission Line Model (TLM) for sheet resistance, XPS for binding energy, UPS for work function), we also find that the binding energy change of ITO indium element is related to the work function of ITO. For lower binding energy of indium element, the ITO film will have higher work function and the ITO / Pentacene interface will have lower contact resistance.