Fabrication of microlens array on silicon surface using electrochemical wet stamping technique

The fabrication of microlens array (MLA) on silicon surface is focused in this paper by taking advantage of a novel micromachining approach, the electrochemical wet stamping (E-WETS). The E-WETS allows the direct imprinting of MLA on an agarose stamp into substrate through a selective anodic dissolution process. The pre-patterned agarose stamp can direct and supply the solution preferentially on the contact area between the agarose stamp and the substrate, to which the electrochemical reaction is confined. The anodic potential vs. saturated calomel electrode is optimized and 1.5 V is chosen as the optimum value for the electrochemical polishing of p-Si. A refractive MLA on an PMMA mold is successfully transferred onto p-Si surface. 151