US 10,120,129 B2 · Semiconductor device and method for manufacturing same

Abstract

Good optical properties can be achieved in an optical waveguide made of polycrystalline silicon. A semiconductor layer that constitutes each of a first optical signal line, a second optical signal line, a grating coupler, an optical modulator, and a p-type layer of a germanium optical receiver is formed by a polycrystalline silicon film. Crystal grains of polycrystalline silicon exposed on an upper surface of the semiconductor layer include crystal grains having flat surfaces parallel to a first main surface of a semiconductor substrate, and crystal grains of polycrystalline silicon exposed on side surfaces (including side surfaces of a protrusion of a protruding portion) of the semiconductor layer include crystal grains having flat surfaces perpendicular to the first main surface of the semiconductor substrate.

Claims19

Dependent claims

A semiconductor device comprising:

a semiconductor substrate;
a first insulating film formed over a main surface of the semiconductor substrate;
an optical waveguide formed on the first insulating film;
and
a second insulating film formed on the first insulating film such that the second insulating film covers the optical waveguide,
wherein the optical waveguide is made of polycrystalline silicon,
crystal grains of the polycrystalline silicon exposed on an upper surface of the optical waveguide include crystal grains having surfaces extending along the main surface of the semiconductor substrate,
crystal grains of the polycrystalline silicon exposed on side surfaces of the optical waveguide include crystal grains having surfaces extending along a direction perpendicular to the main surface of the semiconductor substrate, and
the second insulating film contacts the upper surface and the side surfaces of the optical waveguide and contacts an upper surface of the first insulating film.

6 more elements

A semiconductor device comprising:

a semiconductor substrate;
a first insulating film formed over a main surface of the semiconductor substrate;
a first optical waveguide formed on the first insulating film;
a second insulating film formed on the first insulating film such that the second insulating film covers the first optical waveguide;
a second optical waveguide formed on the second insulating film;
and
a third insulating film formed on the second insulating film such that the third insulating film covers the second optical waveguide,
wherein the second optical waveguide is made of first polycrystalline silicon,
crystal grains of the first polycrystalline silicon exposed on an upper surface of the second optical waveguide include crystal grains having surfaces extending along the main surface of the semiconductor substrate,
crystal grains of the first polycrystalline silicon exposed on side surfaces of the second optical waveguide include crystal grains having surfaces extending along a direction perpendicular to the main surface of the semiconductor substrate, and
the third insulating film contacts the upper surface and the side surfaces of the second optical waveguide and contacts an upper surface of the second insulating film.

8 more elements

Dependencies are inferred from the claim text.

Semiconductor device and method for manufacturing same

Life of this patent

Semiconductor device and method for manufacturing same

Life of this patent

Abstract

Claims19