Patent ID: 11953725
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 12:
13. A grating coupler for silicon photonics, comprising:
a base;
a plurality of grating structures arranged on the base and separated from each other by trenches, the plurality of grating structures each comprising a bottom portion and a top portion, the bottom portion being wider than the top portion by a width of less than 300 nm, the plurality of grating structures having a periodicity of less than 600 nm, the plurality of grating structures being parallel to each other and arranged between a first waveguide portion and a second waveguide portion;
a dielectric material deposited in the trenches; and
a dielectric layer deposited over the plurality of grating structures,
wherein:
the top portions of ones of the plurality of grating structures close to the first waveguide portion are narrower than the top portions of ones of the plurality of grating structures close to the second waveguide portion;
the bottom portions of the ones of the plurality of grating structures close to the first waveguide portion are narrower than the bottom portions of the ones of the plurality of grating structures close to the second waveguide portion;
ones of the trenches corresponding to the ones of the plurality of grating structures close to the first waveguide portion are wider than ones of the trenches corresponding to the ones of the plurality of the grating structures close to the second waveguide portion; and
sums of corresponding ones of the top portions width plus the trenches width are uniform throughout the plurality of grating structures.