硅纳米线的PECVD生长研究

Study on the Growth of Silicon Nanowires by PECVD

本文以硅烷(SiH4)为反应气体,利用等离子体化学气相沉积(PECVD)方法在硅(100)衬底上生长硅纳米晶体、纳米线。应用扫描电镜观察不同条件下生长的样品表面,发现衬底条件对硅纳米结构的影响十分显著。在温度、压强等其它条件相同的情况下,对硅衬底应用Fe3+催化剂处理后,呈纳米线状结构生长,而无Fe催化剂涂覆情况下,基本呈纳米晶体状生长,说明催化剂对Si纳米线的生成起了重要的促进生长作用。通过进一步研究硅纳米晶体、纳米线的等离子增强化学气相生长机理,发现它们以气-液-固(VLS)机制生长。

In this paper, Si nanowires thin films were fabricated Si on substrates using SiH4 as reactive by plasma-enhanced chemical vapor deposition （PECVD）. We found that the growth conditions played a great influence on the nanostructure,the surface of the obtained samples were various under observation of scanning electronic microscopy （SEM）. Si nanowires were obtained on the silicon substrate with Fe catalyzer,while silicon nanocrystals were grown on the substrate without Fe activator,using the same temperature,pressure conditions. It indicates that activator plays an important action of enhance in growth. Based on the study of the growth mechanism of Si nanocrystals,nanowires of PECVD,we found that the growth of them is characteristics of the gas-solid-night （VLS） mechanism.