Method and apparatus for an improved micromechanical modulator

A method for making a micromechanical modulator comprising the steps of:

• (a) depositing a cavity-defining layer on a suitably-prepared substrate;
• (b) patterning the cavity-defining layer into a desired shape that defines a region that will become a modulator cavity and further removes the cavity-defining layer from the substrate in the region;
• (c) oxidizing the substrate in the region;
• (d) depositing a rapidly-etchable layer on the oxidized substrate of step (c);
• (e) patterning the rapidly-etchable layer;
• (f) depositing a membrane-forming layer on the patterned rapidly-etchable layer;
• (g) patterning the membrane-forming layer into a membrane, wherein holes are formed in the membrane;
• and
• (h) removing the rapidly-etchable layer and the oxidized substrate.

A method for forming a feature in a structure wherein there is limited access to a region of a first layer, comprising a first material that must be etched to form the feature, comprising the steps of:

• (a) forming a rapidly-etchable layer on the first layer, the rapidly-etchable layer comprising a second material that is etched rapidly via a first etch relative to the first material;
• (b) forming a second layer on the rapidly-etchable layer;
• (c) delivering the first etch to the rapidly-etchable layer, thereby removing it and forming a conduit;
• and
• (d) delivering to the first layer, via the conduit, one of either the first etch, or a second etch if the first layer is not etchable by the first etch, to remove the region and form the feature.