Electroless Deposition of Noble Metal Nano Particles as Catalyst and Subsequent Micropatterning of Silicon Substrate by Wet Chemical Etching

Abstract

Noble metal particles such as Ag and Pd were deposited site-selectively on Si substrate using colloidal crystal composed of polystyrene spheres as a mask for electroless plating to obtain metallic honeycomb pattern. After metal-assisted chemical etching of Si in HF/H₂O₂, ordered Si convex arrays were formed. On the other hand, isolated-island metal pattern was obtained on Si substrate by hydrophobic treatment with colloidal crystal templating, which acted as a mask for subsequent electroless plating. Si hole arrays formed after chemical etching corresponded to inverse structure of above-mentioned Si convex arrays. The dimensions of the resultant pattern could be adjusted with feature sizes ranging from 3 µm to 200 nm by changing the diameter of the polystyrene spheres used as an initial mask.