摘要
通过运用Si3N4和SiO2作掩膜,采用各向同性和各向异性腐蚀液,利用硅的腐蚀自停止特性,实现了硅梁的纳米宽度控制,同时利用多次氧化在SOI材料上实现了纳米厚度控制,最终成功批量制作了硅纳米线.扫描电镜观测表明,制备的纳米线厚度和宽度都可严格控制在100nm以下,最细的纳米线宽度可以达到20nm.同批样品的宽度变化范围在20%以内.大气中对其电学特性测量表明,剥离了表面氧化层的纳米线的电阻会随放置时间的增长而逐渐增大.进一步实验分析发现水分吸附在其电阻变化中起了重要的作用.
A novel diameter-controllable on-chip silicon nanowire is fabricated by traditional MEMS technology on a siliconon-insulator substrate. The thickness of the nanowires is determined by thermal oxidation,and the width is achieved in the nanometer scale by isotropic and anisotropic self-stop etching with masks of SiO2 and Si3N4 . SEM photos of the nanowires indicate that the thickness and width of the nanowires are both less than 100nm and the thinnest one is less than 20nm. The electronic properties of the as-released silicon nanowires are different from those with thick oxide shells. Their resistance increases gradually with time as they are exposed to air. Further experiments show that the adsorption of water plays a key role in the process.
基金
国家重点基础研究发展规划资助项目(批准号:2006CB300403)~~
