Silicon based optical modulators including vertical slabs and methods of forming

A method of forming an optical modulator structure comprising:

• simultaneously forming a core region, and pluralities of first and second vertical slabs, wherein the core region comprises an optical transmission path having a refractive index that is modulated via electric charge introduced into the core region;
• wherein the plurality of first vertical slabs contacts and are spaced along a first side of the core region to provide a first path for the electric charge to/from the core region;
• and
• wherein the plurality of second vertical slabs contacts and are spaced along a second side of the core region, opposite the first side, to provide a second path for the electric charge to/from the core region.

A method of forming an optical modulator structure comprising:

• forming a trench in a substrate;
• forming a lower cladding layer in the trench;
• depositing an amorphous Si layer on the lower cladding layer;
• patterning the amorphous Si layer using a single mask to simultaneously define a core region pattern and pluralities of first and second vertical slab patterns on the amorphous Si layer;
• etching the amorphous Si layer to faun a core region and a plurality of first vertical slabs on a first side of the core region and a plurality of second vertical slabs on a second side of the core region opposite the first side;
• and
• depositing an upper cladding layer on the core region and on the pluralities of first and second vertical slabs.