Monolithic iii-v-on-silicon opto-electronic phase modulator with a ridge waveguide

A method for fabricating a monolithic integrated electro-optical phase modulator, wherein for fabricating an optical modulation region of the phase modulator the method comprises:

• providing a silicon-based n-type base layer;
• growing an n-type ridge waveguide for propagating light, wherein the ridge waveguide is grown protruding from and extending along the n-type base layer and is made of III-V semiconductor material;
• forming one or more insulating layers on the ridge waveguide, wherein the one or more insulating layers have together a thickness in a range of 1-100 nm;
• and
• forming a silicon-based p-type cover layer on the one or more insulating layers at least above the ridge waveguide,
• wherein the n-type ridge waveguide, the one or more insulating layers, and the p-type cover layer form together a monolithically integrated semiconductor-insulator-semiconductor capacitor for phase modulating the light propagating along the ridge waveguide in the optical modulation region.