用氢气/甲醇混合气体在微波等离子体CVD中合成纳米晶粒金刚石膜

用微波等离子体增强化学气相沉积方法(MPECVD),利用氢气和甲醇的混合气体,在硅片上沉积出纳米晶粒的金刚石薄膜.用扫描电子显微镜(SEM)、拉曼光谱(Raman)、原子力显微镜(AFM)及扫描隧道显微镜(STM)对薄膜的晶粒平面平整性及纯度进行了表征.通过SEM发现,提高甲醇浓度或降低沉积温度可以减小金刚石膜的晶粒尺寸.拉曼光谱显示薄膜中确实存在纳米晶粒的金刚石,并且薄膜的主要成分为金刚石.用AFM测得薄膜表面的粗糙度Rms＜80m,STM观测晶粒的平均尺寸在10～20m之间.研究结果表明,用MPECVD方法,利用氢气和甲醇的混合气体是制备纳米晶粒金刚石膜的一种理想方法.

Nanocrystalline Diamond Films Deposited with Methanol and Hydrogen Mixtures in Microwave Plasma CVD Reactor

Nanocrystalline diamond thin films are grown on silicon substrates by using methanol and hydrogen mixtures in MPECVD(microwave plasma enhanced chemical vapor deposition ) reactor. The evidence of nanocrystallinity, smoothness and purity is obtained by characterizing the samples with a combination of scanning electron microscopy (SEM),Raman spectroscopy,atomic force microscopy (AFM)and scanning tunneling microscopy (STM). SEM images reveal that increasing the methanol concentration or decreasing the deposition temperature can reduce the grain size of diamond films. The Raman band indicates the presence of nanocrystalline diamond and diamond component dominated the film composition. Surface roughness is measured as Rms<80 nm by AFM. The grain size averages are measured as approximately 10-20 nm by STM. Using methanol and hydrogen mixtures in MPECVD reactor can be considered as a promising technique for developing nanocrystalline diamond films.