Method and structure providing optical isolation of a waveguide on a silicon-on-insulator substrate
View Patent ↗Disclosed are a method and structure providing a silicon-on-insulator substrate on which photonic devices are formed and in which a core material of a waveguide is optically decoupled from a support substrate by a shallow trench isolation region.
1. An integrated structure comprising:
a first semiconductor substrate having a shallow trench isolation region formed therein, the trench of the isolation region being filled with a dielectric material having a first index of refraction, wherein the dielectric material comprises silicon dioxide; and
a second substrate attached to the first substrate and including a dielectric material facing the first substrate and a waveguide formed of a semiconductor material over the dielectric material, the waveguide being formed of a material having a second index of refraction greater than the first index of refraction and being located over the shallow trench isolation region.
2. A structure as in claim 1 , wherein the combined thickness of the dielectric material facing the second substrate and the shallow trench isolation region is at least 1000 nm.
3. A structure as in claim 1 , wherein the first and second substrates comprise silicon.
4. A structure as in claim 1 , wherein the waveguide comprises a core region surrounded by a cladding region, the cladding region being formed at least in part by the dielectric material on the second substrate.
5. A structure as in claim 1 , wherein the core region comprises silicon and the cladding region comprises silicon dioxide.
6. A structure as in claim 1 , further comprising an area of the semiconductor material of the second substrate on which an electronic circuit element is formed.
7. A structure as in claim 1 , wherein the attached first and second substrates form a silicon-on-insulator structure.
8. A structure as in claim 1 , further comprising a dielectric material over the semiconductor material of the second substrate.
9. A structure as in claim 8 , wherein the dielectric material over the semiconductor material of the second substrate is part of an interlayer dielectric structure.