Hybrid MOS optical modulator

A method of fabricating an optical modulator comprising:

• forming an isolation trench in a first semiconductor layer carried by a substrate;
• implanting ions in a portion of the first semiconductor layer;
• forming a second semiconductor layer on the first semiconductor layer, the second semiconductor dissimilar from the first semiconductor, a capacitor being defined between the first and second semiconductor layers;
• forming an optical waveguide in the first and second semiconductor layers;
• removing a portion of the second semiconductor layer to expose a portion of the first semiconductor layer;
• forming an electrode on the exposed portion of the first semiconductor layer;
• and
• forming an electrode on the second semiconductor layer.

An optical modulator comprising:

• an optical waveguide;
• a cathode comprising a III-V semiconductor material and formed in the optical waveguide;
• an anode comprising silicon and formed in the optical waveguide, the anode adjoining the cathode, a capacitor being defined between the anode and the cathode;
• and
• a dielectric disposed between the cathode and the anode, wherein the dielectric comprises an oxide of the III-V semiconductor material and an oxide of the silicon of the anode, wherein the III-V semiconductor material comprises indium phosphide.