Integrated MOSCAP waveguide structure and phase modulator comprising same

The invention particularly relates to a waveguide structure of an integrated MOSCAP and a phase modulator comprising the waveguide structure of the integrated MOSCAP. The waveguide structure is composed of a waveguide, a lower electrode layer, an insulator layer and a grid electrode, and a sandwich structure sequentially composed of the lower electrode layer, the insulator layer and the grid electrode from bottom to top is located above the waveguide; the waveguide is made of undoped monocrystalline silicon, and the lower electrode layer is made of a conductive silicon material. According to the phase modulator prepared by adopting the waveguide structure, the high mobility of the lower electrode layer is kept, the doping concentration and the thickness height are more controllable, compared with an existing mode that the whole silicon waveguide serves as the lower electrode, the situation that high carrier concentration is introduced into a non-effective modulation area and additional optical loss is caused