The present invention relates to: a semiconductor device; and a technology of a semiconductor device having an optical device for example.
There is a silicon photonics device of an SIS (Semiconductor Insulator Semiconductor) type as an example of an optical modulator configuring an optical device. The device is configured by: forming a second semiconductor layer with a dielectric layer interposed over a first semiconductor layer formed with an insulating layer interposed over a substrate; and further covering them with an insulating film. The first semiconductor layer configures an optical waveguide (core section) mainly to transmit an optical signal and the second semiconductor layer configures a control electrode mainly to control the transmission state of the optical signal. Further, the insulating film covering the insulating layer as the base of the first semiconductor layer and the first and second semiconductor layers comprises a material having a refractive index of light for a signal lower than the first semiconductor layer and configures a clad section.
Such a silicon photonics device of an SIS type is described in Patent Literatures 1 and 2 for example. In Patent Literature 1, described is a configuration of stacking a transparent electrode that is optically transparent at least in a near-infrared wavelength region over a second conductivity type semiconductor layer formed over a dielectric layer. Further, in Patent Literature 2, described is a configuration of setting the height of a heavily doped region adjacent to a rib section configuring a first silicon semiconductor layer of a rib waveguide shape with a slab section interposed so as to be equal to the height of the rib section.