二氧化硅纳米颗粒的反应离子刻蚀及其在硅纳米针尖制备中的应用

系统地研究了硅衬底上二氧化硅纳米颗粒的反应离子刻蚀（R IE）过程,并在此基础上制备了可用于场发射的硅纳米针尖阵列.首先,采用改进的蒸发法在硅衬底上实现二氧化硅纳米颗粒的单层密排结构,再采用典型的刻蚀二氧化硅的RIE技术同时刻蚀硅衬底和二氧化硅纳米颗粒,在对纳米颗粒尺寸随刻蚀进行而改变的电镜照片分析的基础上,获得了相应的二氧化硅纳米颗粒刻蚀模型,计算得到横向和纵向的刻蚀速率;当刻蚀后的二氧化硅纳米颗粒从衬底上脱落后,进一步对硅衬底的刻蚀可以得到锐利的硅纳米针尖阵列,初步的实验结果表明,所制备的硅纳米针尖具有较好的场发射特性.

RIE of SiO_2 Nanoparticles and Its Application in Preparation of Silicon Nanopillar Array

Reactive ion etching (RIE) of SiO_2 nanoparticles on a silicon substrate has been systemically studied in this paper and a silicon nanopillar array has been prepared with this technique for field emission. A monolayer of SiO_2 nanoparticles was first obtained on a Si wafer by the revised evaporation approach. Then the Si wafer and the SiO_2 nanoparticles were etched by RIE anisotropically with a typical silicon oxide etching recipe. On the basis of analysis of the geometrical data of the shrunk nanoparticles in SEM images, the RIE process of the SiO_2 nanoparticles was modeled, and the horizontal and vertical etching rates were calculated based on the proposed geometrical model. Besides, a further etching of the silicon substrate after the nanoparticles brushed off led to a sharp silicon nanopillar array. Preliminary experiment result indicates that the so-prepared silicon nanopillar has good performance in field emission.