Patent ID: 7447387

Claim:
An electro-optical modulator, comprising: a structural substrate, having an insulating layer on top; a waveguide layer, disposed on the insulating layer; a resonant layer, disposed on the insulating layer, wherein the resonant layer has a curving rim adjacent to the waveguide layer to form an optical coupling region; a gate dielectric layer, covering part of the resonant layer; a dielectric layer, disposed over the resonant layer and covering the gate dielectric layer, wherein the dielectric layer has a first opening exposing part of the resonant layer and a second opening exposing the gate dielectric layer, wherein part of the second opening is adjacent to the curving rim of the resonant layer; a first polysilicon layer, disposed on the exposed region of the resonant layer to serve as a first electrode; and a second polysilicon layer, disposed over the dielectric layer, filling the second opening, being in contact with the gate dielectric layer, part of the second polysilicon layer covering the dielectric layer to serve as a second electrode.