Dense arrays of uniform submicron pores in silicon and their applications

We report a versatile particle-based route to dense arrays of parallel submicron pores with high aspect ratio in silicon and explore the application of these arrays in sensors, optics, and polymer micropatterning. Polystyrene (PS) spheres are convectively assembled on gold-coated silicon wafers and sputter-etched, resulting in well-defined gold disc arrays with excellent long-range order. The gold discs act as catalysts in metal-assisted chemical etching, yielding uniform pores with straight walls, flat bottoms, and high aspect ratio. The resulting pore arrays can be used as robust antireflective surfaces, in biosensing applications, and as templates for polymer replica molding.