【摘要】 研究了纳米金刚石外延薄膜的制备方法及其场发射特性。采用电泳方法将粒径20nm以下的纳米金刚石微晶沉积到Ti电极衬底上,用热丝CVD方法在纳米金刚石微晶薄膜上再外延生长一层含非晶碳金刚石薄膜。用Raman光谱研究了外延纳米金刚石薄膜的结构并在高真空条件下研究了其场发射特性。更多还原

【Abstract】 Diamond material may be ideal electron emission material for vacuum microelectron devices and field emission display because of its low emission work function and better chemistry stability. In most research work on field emission properties of diamond, chemical vapor deposition (CVD) diamond were found to be very attractive for application. But fabrication of diamond emitter with large area and uniform emission properties is difficult. In this research, synthetic diamond nanogrits was deposited onto substrate by electrophoretic method and then diamond layer was grown again on diamond nanogrits by epitaxy method. The aim is to improve emission uniform of diamond emitter.  Epitaxial diamond emitter was fabricated by three steps. First, metal Ti thin film(0.2μm) was sputtered onto silicon substrate, and then diamond nanogrits(<20nm) were deposited onto metal Ti electrode surface by electrophoretic deposition, finally, epitaxial diamond film was grown on synthetic diamond nanogrits surface by microwave plasmaenhanced CVD(MPCVD). V(CH4)∶V(H2)=1∶100. The growth time is 1h. The temperature of Tisilicon substrate is about 850℃. Pressure is kept about 2×103Pa. Raman spectrum is employed to research epitaxial diamond. Measurements of field emission properties are solved in high vacuum chamber at pressure of 10-5Pa. The distance between anode and cathode are about 100μm. The results show that field emission distribution of the diamond nanogrits emitter deposited by electrophoretic method are serious nonuniform, but was improved after epitaxial diamond. Raman spectrum of synthetic diamond nanogrits shows only one sharp peak at 1 334cm-1. But Raman spectrum of epitaxial diamond presents a wide graphite peak between 1 440~1 600cm-1, the peak at 1 335.6cm-1 also become wide.It seems that graphite composition on epitaxial diamond surface is important for improving field emission uniformity.更多还原