纳米絮状碳膜的制备及场发射特性

采用电子回旋共振等离子体化学气相沉积(ECR-CVD)技术,以CH4和H2为源气体,硅片为衬底制备了碳膜。利用拉曼光谱仪和扫描电子显微镜成功研究了基板偏压、沉积时间、CH4浓度等工艺参数的改变对碳膜絮状结构的影响。通过分析碳膜结构和形貌,得出纳米絮状碳膜的最佳工艺参数。通过电流密度-电场(J-E)曲线和Fowler-Nordheim(F-N)曲线,研究了CH4浓度对纳米絮状碳膜的场发射特性的影响。随着CH4浓度的增加,碳膜的阈值电场逐渐降低,发射电流密度逐渐增加。

Preparation and Electron Field Emission Characteristics of Nano-Catkin Carbon Films

Nano-catkin films were prepared on Si substrates by means of electron cyclotron resonance microwave plasma chemical vapour deposition method in a hydrogen and methane mixture. The influences of substrates bias, CH4 concentration and deposition time on the nano-catkin structure of carbon film were investigated by Raman spectroscopy and scanning electronic microscope, respectively. The optimal deposition conditions were obtained by ana-lyzing the images of nano-catkin film. The field emission characteristics were analyzed by using the current density versus electric field(J-E) curves and Fowler-Nordheim(F-N)curves. The threshold electric field of nano-catkin carbon films was reduced with increasing the CH_4 concentration, at the same time emission current density was increased.