NH_3与H_2之比对碳纳米尖端阵列形成的影响

Influences of Ratios of NH_3 to H_2 on Formation of Carbon Nanotip Arrays

以CH4,NH3和H2为反应气体,利用等离子体增强热丝化学气相沉积系统在沉积有碳膜的Si上制备了碳纳米尖端阵列。利用原子力显微镜和扫描电子显微镜分别对碳膜和碳纳米尖端进行了研究,发现碳膜的表面粗糙不平,有许多凸起,在NH3与H2的比例为1/7和1/1时,可形成碳纳米尖端阵列,利用有关等离子体刻蚀理论对碳纳米尖端阵列的形成进行了分析,结果表明,只有在这两个比例下,离子对碳膜内凸起两侧有相同的溅射刻蚀速率,因此可形成碳纳米尖端阵列。

Carbon nanotip arrays were grown from carbon films deposited on silicon substrates by plasma-enhanced hot filament chemical vapor deposition using CH4, NH3 and H2 as reaction gases. The carbon film and carbon nanotip arrays were investigated by atomic force microscopy and scanning electron microscopy, respectively. It is found that the carbon film is rough surface with a lot of spikes and the carbon nanotip arrays can be formed at 1/7 and 1/1 ratios of NH3 to H2, respectively. The formation of the carbon nanotip arrays is analyzed by the theory related to plasma sputter-etching and the result indicates that the formation results from the same sputter-etching rates of ions on both sides of the spikes.