预氧化法制备均匀硅纳米线阵列

Preparation of Uniform Silicon Nanowire Arrays by Pre-oxidation Method

利用双氧水溶液对硅片表面进行预氧化处理,并用改良的RCA法清洗硅片,结合金属辅助化学刻蚀(MACE)制备硅纳米线阵列(Si NWs)。通过表征发现:预氧化清洗相较于传统RCA清洗,能够降低硅片表面微粗糙度,同时提高后续制备的硅纳米线阵列的均匀性。此外,在300～800 nm波段,当硅纳米线的长度相近时,经预氧化清洗制备的硅纳米线阵列反射率降低,当硅纳米线长度为500 nm左右时,反射率降低值大于2. 4%。最后分析了均匀硅纳米线阵列的形成机理。

Silicon nanowire arrays(SiNWs)were prepared by pre-oxidation treatment of the silicon wafer surface using hydrogen peroxide aqueous solution,followed by modified RCA silicon wafer cleaning and then metal-assisted chemical etching(MACE)process.Through characterization,it is found that,in comparison with the conventional RCA cleaning,the pre-oxidation cleaning is able to decrease the micro-roughness of silicon surface and simultaneously improve the uniformity of the subsequently fabricated SiNWs.In addition,when the length of SiNWs is close,the SiNWs prepared by pre-oxidation cleaning,in comparison with the conventional RCA cleaning,have a lower reflectance over the spectral range of 300-800 nm.In particular,when the length of SiNWs is about 500 nm,the reflectance difference for the SiNWs prepared by pre-oxidation cleaning and conventional RCA cleaning is more than 2.4%.Finally,the mechanism for the formation of uniform SiNWs was analyzed.