Manufacture of a silicon waveguide structure

摘要

A process for making a silicon rib wavegide structure is described comporising the following steps: (i) forming a window in a protective layer on the surface of a silicon wafer to expose a part of said surface; (ii) depositing a buffer layer at least over said exposed surface; (iii) carrying out an etch step to etch the buffer layer and silicon outside a protected rib portion thereby to form a silicon rib with the buffer layer on its upper surface; and (iv) forming a layer of cladding at least on side walls of the silicon rib.