A conventional CMOS fabrication technique is used to integrate the formation
of
passive optical devices and active electro-optic devices with standard CMOS electrical
devices on a common SOI structure. The electrical devices and optical devices share
the same surface SOI layer (a relatively thin, single crystal silicon layer), with
various required semiconductor layers then formed over the SOI layer. In some instances,
a set of process steps may be used to simultaneously form regions in both electrical
and optical devices. Advantageously, the same metallization process is used to
provide electrical connections to the electrical devices and the active electro-optic devices.