Vapor-Phase Preparation of Carbonaceous Materials Using Activated Fluorine Species

本研究的目的是开发一种在低于传统方法的温度下气相制备碳质材料的新方法。通过三氟化氮（NF_3）在血浆中的分解得到活性氟，并用于激活烃的分解过程。采用四极杆质谱（QMS）分析了NF_3存在下的分解机理。主要研究结果如下：1。碳质材料的气相制备以苯为碳源制备薄膜。在NF_3存在的情况下，碳质膜的沉积速率明显高于不存在NF_3的情况。在400℃的低温下也能得到碳质薄膜。玻璃板衬底的碳质膜表面平整，而镍板衬底的表面粗糙。随着衬底温度的升高，沉积速率降低。在700℃的温度下进行气相反应，得到了质量最好的碳质膜。当等离子体功率增加时，薄膜的结晶度增加，而沉积速率降低。QMSQMS分析表明，NF_3分解释放出活性氟，并取代苯中的氢生成氟苯。氟苯比苯更容易分解，导致观察到的沉积速率加快。

The aim of this research is to develop a novel method for vapor-phase preparation of carbonaceous materials at temperatures lower than those used in conventional methods. Activated fluorine species was obtained by decomposition of nitrogen trifluoride (NF_3) in plasma, and was used to activate the decomosition process of hydrocarbon. The decomposition mechanism in the presence of NF_3 was analyzed by quadrupole mass spectroscopy (QMS). Major findings are as follows :1.Vapor-phase preparation of carbonaceous materialsBenzene was used as a carbon source for thin film. In the presence of NF_3, deposition rate of carbonaceous film increased significantly when compared with that in the absence of NF_3. Carbonaceous thin films can be obtained even at a low temperature of 400ﾟC.Glass plate substrates gave carbonaceous films of flat surface, wheresas nickel plate substrates resulted in rough surface. When the temperature of the substrate was increased, deposition rate decreased. Carbonaceous films with best quality was obtained by vaporphase reaction at 700ﾟC.When the plasma power was increased, the crystallinity of the resulting films increased, whereas the deposition rate decreased.2.Analysis by QMSQMS analysis revealed that activated fluorine species was released by decomposition of NF_3, and this active species substitutes the hydrogen of benzene to form fluorobenzene. Flurobenzene decomposes more easily than benzene, resulting in the observed enhancement of deposition rate.