MPCVD法合成硼掺杂金刚石薄膜的次级发射性能

发布时间：2018-04-13 20:53

本文选题：硼掺杂金刚石 + 微波等离子体化学气相沉积(MPCVD)　；参考：《中国空间科学技术》2017年02期

【摘要】：为解决电子倍增器、场发射阴极和粒子/光子探测器现有阴极材料次级发射系数低且发射不稳定的问题,对微波等离子体化学气相沉积(Microwave Plasma Chemical Vapor Deposition,MPCVD)法结合H等离子体表面处理工艺制备的不同B2H6/CH4浓度的硼掺杂金刚石薄膜的次级发射能力进行了研究。样品表面扫描电子显微镜和拉曼光谱分析结果显示,硼掺杂金刚石膜表面形貌与未掺杂的金刚石膜相似,样品表面均为高纯度的金刚石相。将置于空气中数日且未经任何表面处理的硼掺杂金刚石样品进行次级电子发射性能测试,结果显示一次电子入射能量为1keV时,得到高达18.3的二次电子发射系数。试验证实这种具有高二次电子发射系数的硼掺杂金刚石膜,暴露空气中由于表面氧化会破坏其表面的负电子亲和势,而真空中加热会使表面重新恢复负电子亲和势,这种负电子亲和势的完整保留,提高了该材料次级发射的稳定性,在器件中具有重要的应用前景。
[Abstract]:In order to solve the problem of low secondary emission coefficient and unstable emission of field emission cathode and particle / photon detector,The secondary emission properties of boron-doped diamond films with different B2H6/CH4 concentrations prepared by microwave plasma chemical vapor deposition (MPCVD) method and H plasma surface treatment were studied.The results of scanning electron microscope and Raman spectroscopy showed that the morphology of boron doped diamond film was similar to that of undoped diamond film and the sample surface was high purity diamond phase.The secondary electron emission properties of boron doped diamond samples which were placed in air for several days without any surface treatment were measured. The results show that the secondary electron emission coefficient of 18.3 is obtained when the incident energy of the primary electron is 1keV.The experimental results show that the boron doped diamond film with high secondary electron emission coefficient will destroy the negative electron affinity of the surface in the exposed air because of the oxidation of the surface, while heating in vacuum will restore the negative electron affinity of the surface.The complete retention of the negative electron affinity potential improves the stability of the secondary emission of the material and has an important application prospect in the device.
【作者单位】：北京真空电子技术研究所微波电真空器件国家级重点实验室;
【基金】：微波电真空器件国家级重点实验室基金(9140C0505011006)
【分类号】：TN104

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