Structures formed using monocrystalline silicon and/or other materials for optical and other applications

摘要

To fabricate an interposer for interfacing waveguides (e.g. optical fiber cables) to transducers, a cavity (410) is formed in a top surface of a substrate. A first layer (520) is formed over the cavity's bottom surface, with one or more gaps in the first layer's top surface. A second layer (3410) is formed in the one or more gaps. The second layer overlaps the first layer. At least part of the first layer is removed to form channels separated from each other by portions of the second layer that are located in the one or more gaps; at least part of the first layer is removed from under the second layer. The second layer portions in the one or more gaps provide one or more spacers in the cavity; these one or more spacers at least partially cover the channels. Waveguides can be placed into the channels.