N型纳米金刚石微结构的制备及其在S波段微波场发射性能研究

发布时间：2018-01-05 00:24

本文关键词：N型纳米金刚石微结构的制备及其在S波段微波场发射性能研究　出处：《西南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着真空微电子、高功率微波、太赫兹技术的快速发展,现有的热阴极和光阴极难以满足射频电子枪对电子束源的要求,发展具有优异电子束发射特性和品质的冷阴极材料已成为当前的研究热点。本论文以微波等离子体化学气相沉积法制备的掺氮N型纳米金刚石(N-NCD)薄膜为研究对象,通过磁控溅射在薄膜表面沉积金属Ni纳米膜,进一步加热Ni纳米膜去润湿后原位形成金属Ni纳米颗粒,以此为掩膜板采用Ar/O2等离子体刻蚀技术,实现了纳米金刚石薄膜的表面微结构化。通过扫描电子显微镜(SEM)、原子力显微镜(AFM)、Raman光谱等测试技术详细研究Ni纳米膜沉积工艺、Ni纳米膜热退火工艺以及Ar/O2等离子体刻蚀工艺参数对N-NCD薄膜微结构化的影响。最后,以所制备的N-NCD微结构为阴极,在S波段微波脉冲电场的激励下,测试并比较了Ar/O2等离子体表面微结构化处理对其微波场场致电子发射性能的影响。实验结果表明:(1)金属Ni纳米颗粒的密度大小、分布均匀程度与磁控溅射镀Ni膜厚度和热退火处理时间紧密相关。当溅射Ni膜厚度为6nm,热退火时间超过20min后,在N-NCD薄膜表面所形成的Ni纳米金属球密度最高、分布均匀性最好;(2)在等离子体刻蚀过程中,加入一定比例的Ar可以增加等离子体对金刚石膜的刻蚀程度。当Ar浓度为45%时,等离子体刻蚀能够形成具有一定刻蚀深度、分布均匀、一致性高的多孔状微结构;(3)表面微结构化处理有助于提高N型纳米金刚石薄膜阴极的S波段微波场场发射电流密度,在72.1 MV/m的微波梯度场下,发射电流密度增加量为41%左右。
[Abstract]:Along with the development of vacuum microelectronics, high power microwave, the rapid development of terahertz technology, the existing hot cathode and the photocathode RF gun is difficult to meet the requirements of electron beam source, the development of excellent electron beam emission characteristics and quality of cold cathode materials has become a research hotspot. In this paper, microwave plasma chemical vapor deposition of nitrogen doped N type nanocrystalline diamond (N-NCD) thin films prepared by magnetron sputtering as the research object, in the deposition of thin film surface metal Ni nano membrane, further heating of Ni nano film dewetting after in situ formation of metallic Ni nanoparticles as a mask by Ar/O2 plasma etching technology, the surface of nano diamond thin films by micro structured. Scanning electron microscopy (SEM), atomic force microscopy (AFM), Ni nano film deposition process with test technology of Raman spectra, Ni nano film thermal annealing process and Ar Effect of /O2 on plasma etching parameters on N-NCD thin film micro structure. Finally, the prepared N-NCD micro structure as cathode in S band microwave excitation pulse electric field under test and compare the Ar/O2 plasma surface micro structured processing affect the electron emission properties of the microwave field. The experimental results show that: (1) the size of metal Ni nano particles, and the degree of uniformity of magnetron sputtering Ni film thickness and annealing time are closely related. When the sputtering Ni film thickness is 6nm, annealing time is over 20min, on the surface of N-NCD film formed by Ni nano metal ball the highest density distribution was better (2); in the plasma etching process, adding a certain proportion of Ar can increase the degree of plasma etching on diamond film plasma. When the concentration of Ar was 45%, the plasma etching is capable of forming the etching depth, uniform distribution, The porous microstructure with high consistency. (3) surface microstructural treatment helps to improve the S band microwave field emission current density of N type nano diamond film cathode, and the emission current density increases by 41% at 72.1 MV/m microwave gradient field.

【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ163;TB383.1

【参考文献】