A periodic array of silicon pillars fabricated by photoelectrochemical etching

作者：Li Xiaopeng; Seo Hong Seok; Um Han Don; Jee Sang Won; Cho YongWoo; Yoo Bongyoung^*; Lee Jung Ho

来源：Electrochimica Acta, 2009, 54(27): 6978-6982.

DOI：10.1016/j.electacta.2009.06.094

• Photoelectrochemical etching
• Silicon pillar array
• Pore separation
• Macroporous silicon
• KOH post-etching

A periodic array of silicon pillars was photoelectrochemically fabricated using the two-step etching process with a n-type Si (1 0 0) substrate. Two key factors, backside illumination and anodic bias, were required to obtain a high-aspect ratio macropore array of silicon. It was found that the initial pore could be separated into two different pores when the applied anodic bias was greater than a certain critical value. The pore size of the macroporous silicon with a high porosity was increased by anisotropic etching in an alkaline solution. Due to destruction of the pore sidewalls, KOH etching allowed for the fabrication of silicon pillars on a large-scale wafer with an improved uniformity. The anisotropic etching behavior of KOH solution led to necking of the silicon pillars when the etching time exceeded 60 s.

• 出版日期2009-11-30