Method for manufacturing a thermo-optic component
A method for manufacturing a thermo-optic component comprises the following steps: a) providing a silicon-on-insulator (SOI) substrate comprising: a surface layer made of single-crystal silicon, extending in a main plane and placed on a dielectric layer, itself placed on a carrier made of silicon, and at least one buried cavity, which is formed in the carrier and which opens under the dielectric layer, b) forming an optical waveguide extending in the main plane and comprising a core formed in the surface layer and encircled by an optical confinement layer including the dielectric layer, c) producing at least one heating element, on the optical waveguide, the heating element being positioned, in the main plane, plumb with a segment of the optical waveguide, or on either side of the segment, the heating element and the segment of the optical waveguide being located plumb with the at least one buried cavity.
1 . A method of forming a thermo-optic component, the method comprising:
providing a silicon-on-insulator (SOI) substrate including:
a single-crystal silicon surface layer extending in a main plane;
a dielectric layer; and
a carrier substrate, wherein the dielectric layer is disposed between the single-crystal silicon surface layer and the carrier substrate, a surface of the carrier substrate defining at least one cavity extending into the carrier substrate adjacent the dielectric layer;
forming an optical waveguide extending in the main plane and comprising a core in the single-crystal silicon surface layer, the optical waveguide surrounded by an optical confinement layer comprising the dielectric layer; and
forming at least one heating element proximate the optical waveguide, the at least one heating element positioned, relative to the main plane, plumb with a segment of the optical waveguide, or on either side of the segment of the optical waveguide, the at least one heating element and the segment of the optical waveguide located plumb with the at least one cavity;
after providing the SOI substrate including the single-crystal silicon surface layer, the dielectric layer, and the carrier substate with the surface of the carrier substrate defining at least one cavity, forming an aperture through the SOI substrate, the aperture extending to the at least one cavity; and
altering a pressure within the at least one cavity.
2 . The method of claim 1 , further comprising plugging the aperture to hermetically seal the at least one cavity with the altered pressure therein.
3 . The method of claim 1 , wherein the at least one cavity is hermetically sealed while forming the optical waveguide and forming the at least one heating element.
4 . The method of claim 1 , wherein the dielectric layer comprises silicon oxide and has a thickness between 100 nm and 3 microns.
5 . The method of claim 1 , further comprising forming the surface layer to have a thickness between 100 nm and 500 nm.
6 . The method of claim 1 , wherein forming the optical waveguide comprises forming an additional dielectric layer defining part of the optical confinement layer, the additional dielectric layer having a thickness between 0.5 and 1.5 microns.
7 . The method of claim 1 , further comprising forming the at least one cavity to have lateral dimensions, in the main plane, between 10 microns and three millimeters, and a depth, along an axis normal to the main plane, between three microns and 100 microns.
8 . The method of claim 7 , further comprising forming the at least one cavity to have a depth between 5 and 10 microns.
9 . A method of forming a thermo-optic component, comprising:
forming at least one thermo-optic component according to a method as recited in claim 1 ; and
forming a switch, a phase-shifter, a modulator, a laser emitter, an amplifier, a directional coupler, a filter and/or a multiplexer using the at least one thermo-optic component.