中文摘要：

以铜（Cu）作为催化剂，采用两步化学腐蚀法成功制备了微纳米多孔硅（PS）。本文方法成本低廉、操作简易。系统研究了腐蚀液中H202浓度、Si衬底掺杂浓度、腐蚀液温度和腐蚀时间对PS表面形貌和腐蚀深度的影响，并得到最佳制备参数。高、低掺Si衬底所采用的最佳配比腐蚀液中的H2O2浓度分别达到0．70mol／L和0．24mol／L。在25℃腐蚀液中，腐蚀2h得到约200nm深的纳米级孔洞，其表面反射率在宽波段内降低到5％以下；而在50℃腐蚀液中，经过2～4h的腐蚀，可得到14-41μm深的结构稳定的微纳米级孔洞。文中还对Cu辅助腐蚀与其他金属辅助腐蚀（MACE）作了对比，分析了Cu辅助腐蚀获得锥状孔洞的原因和机理。

英文摘要：

Ahstract ：Porous silicon with micro-nano sizes has been prepared by the metal-assisted chemical etching approach with Cu nanoparticles as the catalyst agents. This method has the advantages of low cost and simple operation. The effects of the preparation condition on the morphologies and etching depth of the porous structures is discussed, such as the concentration of H2O2, the doping level of silicon substrate, the temperature of etching solution and the etching time. An optimal etching condition is obtained, the concentration of H2O2 in the reactant is more than 0. 70 mol/L for highly doped silicon substrate,and more than 0.24 mol/L for lightly doped silicon substrate. Nano porous structures with layer thickness a- bout 200 nm are obtained after etching for 2 h at the temperature of 25℃. The average surface reflectivity of the prepared nanostructures is under 5% for the wide band. While at the optimal temperature of 50℃, stable structures of micro-nano porous silicon with depth about 14-41μm are achieved after etching for about 2-4 h. The formation mechanism of the surface morphology of the Si wafers under different reactant concentrations can be explained with the hole injection model. The action of Cu and other metals on the etching is studied,and the formation of the pores with cubic cone shape is also analyzed. Key words：metal-assisted chemical etching （MACE）~ Cu catalysis; porous silicon （PS）~ nano-structure~ surface anti-reflection