Anisotropically etched Si molds for fabricating fine optical components

Here we demonstrate two fine optical components fabricated by replica-molding from anisotropically etched Si molds. One component is microcavity in micro-scales and the other is grating coupler with a pitch of 500 nanometer. We investigated the feasibility of two methods for the microfabrication of the Si molds: one method is for making hundreds of micrometer size Si molds by using conventional photolithography and reactive ion etching (RIE)technique combined with post anisotropical crystalline etching; and the other is for fabricating nanoscale Si molds by using electron beam lithography and fast atom beam etching. By using the molds, a novel simple process suitable for fabrication of micro periodic structure in optical waveguide was presented. Periodicities in excess of 5000 lines/mm were successfully transferred from silicon mold to polymer layer. The yield, repeatability and efficiency of the original master are very good. This technique can also be used to fabricate other nanometer-scale structures.