Patent ID: 8242564

Claim:
A semiconductor structure, comprising: a substrate; a first insulating layer over the substrate; in a transistor region, a first semiconductor layer over the first insulating layer, a second insulating layer over the first semiconductor layer, a second semiconductor layer over the second insulating layer, and a transistor having a gate dielectric, the gate dielectric over and in physical contact with a top surface of the second semiconductor layer, wherein the first semiconductor layer has a bottom surface and a top surface opposite the bottom surface, and wherein the top surface of the first semiconductor layer is between the bottom surface of the first semiconductor layer and the second insulating layer; and in an optical device region, a waveguide device over the first insulating layer, wherein the waveguide device has a bottom surface and a top surface opposite the bottom surface, wherein the bottom surface of the waveguide device is substantially coplanar with the bottom surface of the first semiconductor layer, wherein the top surface of the waveguide device has a first portion and a second portion, the second portion being located higher than the first portion with respect to the bottom surface of the waveguide device, wherein the waveguide device comprises a continuous semiconductor material, wherein the second portion of the top surface of the waveguide device is substantially coplanar with the top surface of the second semiconductor layer, and wherein the continuous semiconductor material is epitaxially grown on the second portion.