化学刻蚀硅中电荷转移和纳米结构的形成

Charge Transfer and Nanostructure Formation in Chemical Etching of Silicon

Turner机理对于化学刻蚀中多孔硅形成的描述中,并未对表面活性数据和纳米结构的形成进行详细解释。通过研究发现氧化物在纳米多孔硅薄膜的形成中并不起重要作用,基于对化学刻蚀和纳米结构形成机理的理解提出了刻蚀溶液选择的七条规则。使用这七条规则尝试了三种新的含有Fe3+,VO2+和Ce4+的刻蚀溶液并证实能有效制备多孔硅。这些溶液可以避免由硝酸盐/亚硝酸盐为基础的刻蚀溶液所造成的问题,其优点包括无需活化、诱导时间缩短以及厚度均一膜的可重复性,因而是化学刻蚀工艺中一个重要的进展。

In the description of the Turner mechanism for the porous silicon formation during the chemical etching, the surface active data and nanostructure formation were not explained in detail. It is found that the oxide does not play an important role in the formation of the nanoporous silicon film. Based on the understanding of the chemical etching and nanostructure formation mechanism, the seven rules to choose the etching solution were proposed. Using the seven rules,three new etching solutions contained Fe^3＋,VO^2＋ and Ce^4＋ were tried. And it is confirmed that these solutions can prepare the porous silicon effectively. These solutions can avoid the problems caused by the nitrate/nitrite-based etching solutions, their advantages include without activation,shorter induction time and reproducibility of films with uniform thickness, which is an important progress of the chemical etching process.