掺氮N型纳米金刚石薄膜的制备与S波段微波场发射性能研究

发布时间：2018-02-04 04:59

本文关键词： 掺氮N 型纳米金刚石薄膜微波场发射微波等离子体化学气相沉积　出处：《西南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：金刚石由于其优异的物理化学性能引起人们的关注,特别是CVD金刚石薄膜技术的发展,通过对金刚石薄膜进行不同杂质的掺杂,获得所需要特定性能的金刚石薄膜,在电子束源以及半导体领域有着非常重要的意义。采用微波等离子体化学气象沉积(MPCVD)方法在单晶Si基底上制备不同生长条件的掺氮N型纳米金刚石(NCD)薄膜,通过场发射电子显微镜(FESEM)、激光Raman光谱、原子力探针显微镜(AFM)和X射线衍射仪分析了所制备样品的表面形貌和组成结构,详细研究了不同反应气压、温度、Ar含量和CH4浓度对掺氮NCD薄膜性能的影响,结果表明:在Ar-CH4-C3H6N6的体系下,随着反应气压和CH4浓度的增加,薄膜的颗粒尺寸和表面粗糙度均先减小后增加,而薄膜中SP2相含量则呈增加趋势;随着反应温度的增加,薄膜中的颗粒尺寸减小,而薄膜中SP2相则先减小,后增加;随着Ar含量的增加,颗粒尺寸和薄膜中金刚石相含量均减少。并在脉宽3.2μs、峰值场强极值为85 V/μm的微波场以及10-5 Pa真空环境条件下测试分析不同CH4含量制备的掺氮NCD薄膜样品的电场发射特性,并比较了微波场发射前后的SEM和Raman的变化,结果表明:低CH4浓度下制备的掺氮NCD薄膜具有较好的场发射性能,而且所有样品的F-N曲线均为直线,可知这些样品的发射遵循经典的场致发射电子特征规律,在67.7 V/?m电场下,最高发射电流密度为144.8 mA/cm2;比较场发射前后的薄膜表面形貌与物相组成,均变化较小,可知所制备的掺氮NCD薄膜在微波场发射下具有很好的稳定性。
[Abstract]:Diamond has attracted much attention because of its excellent physical and chemical properties. Especially with the development of CVD diamond film technology, diamond films are doped with different impurities. The diamond films with specific properties are obtained. It is of great significance in the field of electron beam sources and semiconductors. Microwave plasma chemical meteorological deposition (MPCVD). Methods Nitrogen-doped N-type nanocrystalline diamond (NCD) films were prepared on single crystal Si substrates under different growth conditions. The surface morphology and structure of the samples were analyzed by field emission electron microscopy (FESE), laser Raman spectroscopy, atomic force probe microscopy (AFM) and X-ray diffractometer (XRD). The effects of different reaction pressure, temperature, ar content and CH4 concentration on the properties of nitrogen-doped NCD films were studied in detail. The results showed that: in the system of Ar-CH4-C3H6N6. With the increase of reaction pressure and CH4 concentration, the particle size and surface roughness of the film decrease first and then increase, while the content of SP2 phase in the film increases. With the increase of the reaction temperature, the particle size in the film decreases, while the SP2 phase in the film decreases first and then increases. With the increase of ar content, both the particle size and the diamond phase content in the film decrease, and the pulse width is 3.2 渭 s. The electric field emission characteristics of nitrogen-doped NCD thin films prepared with different CH4 content were measured and analyzed under microwave field with peak field intensity of 85 V / 渭 m and vacuum environment of 10 ~ (-5) Pa. The changes of SEM and Raman before and after microwave field emission were compared. The results showed that the nitrogen-doped NCD films prepared at low CH4 concentration had better field emission properties. Moreover, the F-N curves of all samples are straight line. The emission of these samples follows the classical field emission electron characteristic law, at 67.7 V /? Under m electric field, the maximum emission current density is 144.8 Ma / cm ~ 2; Compared with the surface morphology and phase composition of the films before and after field emission, the results show that the nitrogen-doped NCD films have good stability under microwave field emission.
【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;TB383.2

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